The vegetation of the páramos of the Colombian Cordillera Oriental by JPZ.

THE VEGETATION OF THE PARAMOS OF THE COLOMBIAN CORDILLERA ORIENTAL

PROEFSCHRIFT TER VERKRIJGING VAN DE GRAAD VAN DOCTOR IN DE WISKUNDE EN NATUURWETENSCHAPPEN AAN DE RIJKSUNIVERSITEIT TE UTRECHT, OP GEZAG VAN DE RECTOR MAGNIFICUS PROF. DR. M. A. BOUMAN, VOLGENS BESLUIT VAN HET COLLEGE VAN DECANEN IN HET OPENBAAR TE VERDEDIGEN OP MAANDAG 1 JUNI 1981 DES NAMIDDAGS TE 4.15 UUR

DOOR

ANTOINE MARIE CLEEF geboren op 8 September 1941 te Heythuysen

PROMOTORES : PROF. DR. T. VANDER HAMMEN (U niversiteit van Amsterdam) PROF. DR. A.L. STOFFERS PROF. DR. M.J .A. WERGER

Aan de nagedachtenis van mijn vader Aan mijn moeder

ACKNOWLEDGEMENTS At the completion of this thesis I express my sincere gratitude to Dr . T. van der Hammen (University of Amsterdam) for directing me towards the study of equatorial high mountain biota of Colombia and for his long-standing friendship and support. He thaught me tropical Andean ecology in terms of time and space . I am much indebted to Professor Dr. A.L. Stoffers , who succeeded the emeritus professor Dr.J.Lanjouw and the late Dr . P . A.Florschutz as promotor; he allowed me all freedom and facilitated my studies on the vegetation of the tropical Andes in the Institute of Systematic Botany in Utrecht. I also thank Professor Dr . M. J.A . Werger , who introduced me to modern methods of vegetation classification and drew my attention to morphological characters of the vegetation . They all gave full and constructive criticism on the manuscript . The present study was financially supported by the Netherlands Organisation for the advancement of Tropical Research (WOTRO) , The Hague (grants W 85-43 , W 85-111, and B 85-148) . The continuous interest in and support of our studies by WOTRO is gratefully acknowledged . The Hugo de Vries Laboratory , Amsterdam , provided important help with sample analyses and dating . In Colombia our base was at the Instituto de Ciencias Naturales-Museo d~J Historia Natural of the Universidad Nacional in Bogota. The past and present directors, Dr . A. Fernandez-Perez and Dr . P . Pinto-Escobar, strongly promoted our studies and generously offered us facilities and help with identification . We enjoyed the hospitality of our Colombian friends and colleagues during fieldJWork intervals from 1971-1973 . Dr . R. Jaramillo-Mejia introduced us to the 路 vascular flora of the paramos; special support was given by Dra . M. T. Murillo, Dr. S. Dfaz-Piedrahita , Dr . H. Garcfa-Barriga, Dr . L. E. Mora-Osejo and Dr . L. Uribe-Uribe <t) . Most helpful and hospitable were all people living in the chilly paramos; to them is this study specially dedicated . I am sincerely grateful to the many taxonomists who helped me with the identification of my material . They are all listed in the introductory chapter. Dr . J. Cuatrecasas (Washington , DC . ) and Dr . Rob Gradstein (Utrecht) gave useful and original comments on part of the manuscript and advise during the preparation . Thanks are also due to the staff and personel of the Institute of Systematic Botany in Utrecht, specially to Harrie Sipman for organizing the identification of the lichens, to Guido van Reenen for the preparation the tables , to Dr . Fred Daniels for syntaxonomical advises, to Mr . T. SchLpper and Mr. H.R . Rypkema for skillfully inking my original drawings , to Mr . W. G. Driehuis and Mr. G. Cornelissen for handling and mailing the herbarium specimens and to Mrs. J . R. A. J . Hendriks-Halla and Mrs . A. Holla-Smit for the final typewriting . The companionship and help of my wife Mieke during all the fieldwork and afterwards and our love for Colombia were a substantial contribution to this study , virtually our joint effort. We are greatly indebted to Mrs . L. Rojas de Ma-lo, Bogota, and her family, who made us a home during our stay in Colombia .

Contents

TABLE OF CONTENTS page Acknowledgements I.

INTRODUCTION, GENERAL DATA AND METHODS

THE CORDILLERA ORIENTAL OF COLOMBIA: GENERAL DATA Topography , geology , geomorphology and soils Climate, Paramo flora vascular plants musci hepaticae lichenes algae macro fungi Phytogeography Botanical exploration Paramo vegetation previous investigation the present study Morphological characters of paramo vegetation Paramo fauna Land use and human impact Evolution and Quaternary history of paramo climate and vegetation METHODS AND MATERIALS General concepts Field methods and materials Laboratory methods and synthesis II.

ALTITUDINAL ZONATION AND OUTLINE OF THE ZONAL PARAMO VEGETATION

ALTITUDINAL ZONATION Atmospherically dry paramo slopes Atmospherically humid paramo slopes Paramo vegetation zonation, upper forest-line , altitude and climate SHORT SURVEY OF THE ZONAL COMMUNITIES *)

12 12 17

21 21 22 22 22 23 24 24

25 26 26 26 27

29 31

36 36 36 39.

45 45 45 47 49 51 51

THE SUBPARAMO

EspeZetiopsis 2. Subparamo shrub of Senecio vaccinioides 3 . Shrub of Eupatorium (Ageratina } tinifoZium 4. Shrub and dwarffores t of the "Vaccinion fZoribundi " Cuatrecasas 1934 I. Shrubparamo with

)

Introduction s h r u b p a r a m o (or lower subparamo)

The sequence of communities and syntaxa is based on physiognomy and does not reflect syntaxonomical rank or hierarchic position .

52 53 53

54 54

Contents

Arcytophyllum - d w a r f s h r u b

page p a r a m o

(or upper subparamo) 5. Dense Ar cytophyllum nitidum 6 . Dwarfshrub of Arcytophyllum Sporobolus lasiophyUus and 7 . Dwarfshrub of Arcytophyllum

dwarfshrub nitidum with

Aq}]YJ;!.Q_cUne_ lehman11,ii nitidum with

Diplostephium phylicoides 8. Communities of Arcytophyllum nitidum in bamboodwarfshrub paramos 9. Dwarfshrub of Gaultheria ramosissima and Disterigma empetrifolium with Arcytophyllum

caracas anum

58 p

r a m

10. Community of Swallenochloa with Sphagnum and/or Breutelia (azonal) II. Community of SWallenochloa with Eryngium humile and Jensenia erythropus I lL Community of SWaUenochloa with Rhynchospora paramorum/Castratella piloselloides and Oreobolus obtusangulus ssp. rubrovaginatus 13. Community of SWallenochloa with Oreobolus obtusangulus ssp. rubrovaginatus a) type with Rhacocarpus purpurascens, Oritrophium peruvianum and Eriocaulaceae b) type with Hypericum sp. b u n c h g r a s s

l o w e r

a m

b u n c h g r a s s

a m o

CastrateUa 16. Lower CaZamagrostis effusa bunchgrassparamo with OreoboZus obtusangulus ssp. rubrovaginatus 17. Lower CaZamagrostis effusa bunchgrassparamo with Espeletia argentea or E. boyacensis 18. Acaeno cyZindristachyae - Plantaginetum sericeae ass. nov.

b u n c h g r a s s

p a r a m o

19. Upper CaZamagrostis effusa bunchgrassparamo with EspeZetiopsis 20 . Upper Calamagrostis effusa bunchgrassp.aramo with Espeletia

THE SUPERPARAMO 1 o w e r

s u p e r p a r a m o

21. Loricarietum compZanatae ass . nov~ a) pernettyetosum prostratae subass. nov. (prov.) b) racomitrietosum crispuZi subass. nov. (prov . ) 22 . Shrub of Senecio vaccinioides and Diplostephium

rhomboidale

61 61 62

14. Lower Calamagrostis effusa bunchgrassparamo with Espeletiopsis 15. Lower CaZamagrostis effusa bunchgrassparamo with EspeZetia, OreoboZus obtusanguZus and

u p p e r

57 58

THE GRASSPARAMO b a m b

63 63

64 65 66 66 68 68 69 70 72 72 75 75

23. Community of Pernettya prostrata and LuzuZa

Contents 7 page

racemosa 24. Community of Espeletiinae with Geranium

sibbaZdioides 25. Community of Agrostis brevicuZmis with

AcauZimaZva purdiei 26. Community of Senecio niveo-aureus 27. Community of VaZeriana pZantaginea with

Racomitrium crispuZum 28. Other zonal lower superparamo communities a) community of LachemiZZa nivaZis b) dwarfshrub of Niphogeton josei

78 78 79 80

s u p e r p a r a mo

THE AZONAL PARAMO VEGETATION

u p p e r Ill.

AQUATIC COMMUNITIES

DITRICHO SUBMERSI - ISOETION all. nov. (I S 0 E T E T E A Br. Bl. 29. Isoetetum karstenii ass. nov. a) subass. typicum subass. nov. b) ditrichetosum subass. nov. 30. Isoetetum gZaciaZis ass. nov. (prov.) 31. Isoetetum sociae ass. nov. 32. Isoetetum andico Zae ass. nov. 33. Isoetetum cZeefii ass. nov. 34. Isoetetum paZmeri ass. nov. aa) var. of DrepanocZadus exannuZatus var. nov. ab) var. of spha~um cuspidatum var. nov. 35. Community of Isoet~ s boyacensis TILLAEETALIA ord. nov. (LIMO SELLETEA cl. nov. prov.) TILLAEION PALUDOSAE all. nov. 36. TiZZaeetum paZudosae ass. nov. a) isoetetosum subass. nov. b) typicum subass. nov. 37. Communities of CaZZitriche and RanuncuZus spp. 38. Communities of LimoseZZa australis POTAMETO - MYRIOPHYLLION ELATINOIDES all. nov. prov. (P 0 T A'M E TEA Tx.& Pr . 1942) 39. Communities of Potamogeton spp. and Scorpidium saorpioides 40. HydrocotyZo ranuncuZoides - MyriophyZZetum eZatinoides ass.nov. JUNCO ECUADORIENSIS- ELEOCHARITION MACROSTACHYAE all. nov. 41. EZeocharitetum macrostachyae ass. nov. a) myriophyZZetosum eZatinoides subass. nov. b) tiUaeetosum paZudosae subass. nov. 42. EZatino chiZensis- Juncetum ecuadoriensis ass. nov.

81 1937) 82 83 83 84 84 86 87 88 89 89 89 90 91 92 94 94 95

96 97

98 99

100 101 102 103 103

Contents

page

RHEOPHYTIC COMMUNITIES 43. PhiZonoto - Isotachidetum serruZatae ass. nov. 44. Dendrocryphaeo ZatifoZiae -PZatyhypnidietum riparioides Cleef & Gradstein ass. nov. Other aquatic communities 45. Community of EZeocharis acicuZaris 46. Community of Equisetum bogotense 47. Lemno- AzoZZetum fiZicuZoides (Br.Bl. 1952) Segal 1965

REEDSWAMPS & MIRES

MARCHANTIO - EPILOBIETALIA order nov. GALIO THIANAE - GRATIOLION PERUVIANAE all. nov. CARICENION PICHINCHENSIS suball. nov. 48. Senecionetum reissiani ass. nov. 49. Caricetum pichinchensis ass. nov. SO. Community of Carex pichinchensis and PoZytrichum commune Other cyperaceous communities 51. Community of Carex acutata 52. Community of Carex jamesonii 53. Cyperetum rivuZaris ass. nov.(prov.)

CALAMAGFiOSTION LIGULATAE all. nov.

lOS

106 107 107 107 108 109 110 110 Ill

112 113 114 115 liS

115 116 117 118

BRYO-CARICENION BONPLANDII suball. nov. 54. Lupino aZopecuroides - MimuZetum gZabratae

119

ass. nov. 55. Geranio confertae - CaZamagrostietum ZiguZatae ass. nov. a) drabetosum subass. nov. (prov.) b) breuteZietosum subass. nov. ba) variant of CampyZopus cavifoZius var. nov. c) CaZamagrostis ZiguZata community with BreuteZia aZZionii, Senecio niveo-aureus and LuzuZa

120

gigan tea Other CaZamagrostis ZiguZata communities

121 122 123 123 124 124

56. Community of CaZamagrostis ZiguZata with Mantia

fontana

124

57. Community of CaZamagrostis ZiguZata with Sphagnum

sancto - josephense 58. Community of CaZamagrostis ZiguZata with DrepanocZadus aduncus and CaZZiergoneZZa cuspidata 59. Community of CaZamagrostis ZiguZata with IsoZepis sp. (5603) and CaZZiergoneZZa cuspidata 60. Superparamo vegetation with CaZamagrostis ZiguZata

125 125 126 126

FLUSH VEGETATION & CUSHIONBOGS

Contents 127

WERNERIETEA cl. nov. (prov.)

127

WERNERIETALIA ord. nov.

128

~ITROPHIO-

WERNERION CRASSAE-PYGMAEAE all. nov. 61. Cariai peuaophilae- Wernerietum arassae ass. nov. (prov.) a) wernerietosum arassae subass. nov. (prov.) aa) var. of Lysipomia sphagnophi la yar.â&#x20AC;˘ nov. b) aariaetosum peuaophilae subass. nov. (prov.) bb) var. of Campylopus cf. inaertus var. nov. (prov.) 62. Oritrophio limnophili - Wernerietum pygmae ass. nov. a) subass. typiaum subass. nov. aa) var. typiaum var. nov. (prov.) ab) var. of Breute lia lorent2ii var. nov. (prov.) - ac) var. of Sphagnum ayalophyllum var. nov. ad) var. of DY.epanoaladus râ&#x201A;Ź_~ var. nov. ae) var. of Saorpidium saorpioides var. nov. b) aotuletosum minutae subass. nov.

GENTIANO- ORITROPHION all. nov. (prov . ) 63. Flosaaldasio hypsophilae - Distiahietum musaoides ass. nov. 64. Community of Distiahia musaoides with Isotaahis serrulata and Campylopus fulvus 65. Hyperiao lancioides - Plantaginetum rigidae ass.nov. a) gentianelletosum nevadensis subass. nov.

1 30 131 132 132 133 T33 134 135 136 136 136 137 13 T 137 138 140 141 142 143

b) breutelietosum subass. nov. bb) var. of Valeriana plantaginea var. nov.

144 145

66. Oritrophio peruvianae - Oreoboletum obtusanguli ass. nov. a) subass, typiaum subass. nov. aa) var. of Rhacocarpus purpurascens var. nov. b) xyridetosum aautifoliae subass. nov.

145 147 147 148

SPHAGNUM BOGS 67. Sphagnum bog with Espeletia and Blechnum loxense 68. Sphagnum bog with SWallenoahloa 69. Sphagnum bog with giant Puya a) Sphagnum bog with sWallenochloa and Puya

goudotiana b) Sphagnum bog with Puya aristiguietae 70. Xyris - Sphagnum bog a) Espeletia - Xyris - Sphagnum bog aa) with Campylopus aucullatifolius ab) with Oreobolus obtusangulus b) Xyris aautifolia - bog Other Sphagnum communities

149 151 151 151 !51 152 15 3 153 153 154 154 154

Contents SHRUB & DWARFFORESTS

page ISS

SHRUBBY COMMUNITIES

IS7

71. DipZostephietum r evotuti a ss . nov . 72 . Aragoetum abietinae a ss . nov. a ) swaZZenochZoetosum subass. nov. b) puyetosum subass. nov. 73 . Senecionetum andicoZae ass. nov . (prov.)

JS7 JS8 IS9 160 160

shrub of Hypericum spp . 74 . Hypericetum ' ZaricifoZii a s s. nov . 7S . Community of Hyper icum ZaricifoZium ssp . Zar icifoZium 76. Shrub of Hypericum Zycopodioides 77. Shrub of Hypericum magnifZorum ~路 Shrub of Hypericum goyanesii 79 . Shrub of Hyper icum thuyoides 80. Shrub of Hyper icum humboZdtianum 81. Shrub of Hyper icum trianae a nd Senecio vaccinioides 82. Dwarfshrub of Hypericum juniperinum 83. Other hypericaceous communities

161 16 1 163 163 164 164 164 164 164 164 16S

84 . Senecionetum ni tidi ass . nov. 8S . Senecionetum vernicosi ass . nov. 86. Cortader io ser icanthae - ArcytophyZZetum caracasani a ss . nov. 87. Myricetum par vifoZiae as s. nov . (pr ov.)

167 170

88. Shr ub of DipZostephium aZveoZatum other dwarfshrub of Compositae

172

89 . 90. 91 . 92. 93. 94. 95. 96 . 97 .

17 2 17 2 17 2 17 3 173 173 173 174 174

Dwarfshrub of DipZostephium gZutinosum Dwarfsh r ub .of DipZostephium juajibioyi Dwa r fshrub of DipZostephium coZumbianum Dwarfshrub of DipZostephium rupes t r e Dwarfshrub of Senecio guicanensis Dwarfshrub of Senecio cacaosensis Dwarfshrub of Senecio guantivanus Shrub of Senecio vaccinioides Other dwarfshrub communities

DWARFFORESTS 98 . 99. 1路00 . 101 . 102. 10 3. 104 . lOS .

Dwarfforest of PoZyZepis quadrijuga Dwar f forest of HesperomeZes cL goudotiana Dwarfforest of EscaUonia myrtiUoides Dwarffore st of Gaulther ia ramosissima and Aragoa

perez- arbeZaeziana Dwarfforest of Gynoxys aZbivestita Other dwarfforests of Gynoxys Senecionetum f Zos- fragrantis ass . nov . (prov . } Dwarfforest of Dip Zos t ephium r homboidaZe

DRY & HUMID MEADOWS GRASSY MEADOWS 106 . LorenzochZoetum erectifoZiae ass . nov . 107 . Aciachnetum puZvinatae Var e s chi 19S3 em . Cleef

16S 166

171

174 174 17 6 176 177

179 179 180 18 2

183 183

183 18S

Contents 108. Muhlenbergietwn fastigiatae a路ss. nov . 109. Agrostietwn foliatae ass. nov. (prov.)

187 189

ROSACEOUS HERBFIELD

190

110. Community of Agrostis breviculmis and Lachemilla Ill.

pinnata Agrostio breviculmis- Lachemilletwn orbiculatae ass. nov.

112. Community of Acaena cylindristachya

SCREE & OUTCROP VEGETATION

190 191

193 193

113. Moss vegetation of Rhacocarpus purpurascens 193 and Racomitriwn crispulwn 114 . Community of Thamnolia vermicularis and Alectoria cf. ochroleuca 194 115. Community of Senecio niveo-aureus and Erytrophyllopsis andina Notes on bryophyte communities 194 116. Community of Senecio swnmus 195 117. Rockshelter vegetation 195 OTHER COMHUNITIES 118. Azorelletwn multifidae ass. nov. (prov.) 119 . Bamboo-grove of Neurolepis aristata 120. Dense Espeletia stemrosette communities 121. Community of Orthrosanthus chimboracensis

IV.

DISCUSSION AND CONCLUSIONS

197 197 198 199 199

201

GENERAL COMMENTS

201

Vegetation in relation to temperature and humidity Growth forms & leaf sizes Phytogeography

201 204 205

ZONAL PARAMO VEGETATION

206

AZONAL PARAMO VEGETATION

207

FUTURE RESEARCH

215

REFERENCES

217

Appendices: I. figures I - 91 2. Alphabetic list of the vascular flora and authorities 3. Locality and habitat data releves

229

Abstract - Resumen - Samenvatting

318

301 311

INTRODUCTION, GENERAL DATA AND METHODS

The name paramo was used since _the early days of the Spanish conquest for the high, more or less open chilly areas of the northern Andes. The neotropical paramos are located in the humid tropical Andean mountains , and occur as an altitudinal belt between the uppermost forests and the perennial snow . The following geobotanic and physiographic features characterize paramo plantcover. Zonal vegetation in these tropical mountains is dominated by bunchgrasses (Calamagrostis ) and/or low bamboos (Swallenochloa), rosette plants and shrubs with small leaves. Caulescent stemrosettes of the Espeletiinae (Heliantheae, Compositae) are physiognomically the most characteristic element Azonal Sphagnum bogs and cushionbogs abound. The vascular flora belongs to the richest in genera and species of the high mountains in the world. Alpine rankers support zonal vegetation and histosoles are most common in azonal waterlogged areas . Annual precipitation varies from 700 to more than 3000 mm. Mist and clouds are very frequent. Temperatures fluctuate very much in 24 hours . Neotropical paramos are present in the northern Andes (Ecuador - Venezuela) with outliers towards Peru and Bolivia, and in Panama and Costa Rica. Most of the paramos are located in Colombia; the Cordillera Oriental, the present study area is one of the main areas (Fig. 1). Paramo-like vegetation is further present on the summit of Cerro Neblina (Brasil-Venezuela) and on Itatiaia (Brasil), but here it is floristically different in many respects. A number of authors rank the open vegetation on the high equatorial mountains of Africa and Malesia also under paramos . THE CORDILLERA ORIENTAL -OF COLOMBIA: GENERAL DATA Topography, geology, geomorphology and soils Topography I

The Colombian Cordillera Oriental extends between ! 0 N 76°30 W and 8° 30'N; ~ts easternmost position is the Sierra Nevada del Cocuy at about 72°\-J. The mair. axis runs from the Macizo Colombiano in NNE direction and continues from the Cocuy area NNW to its norternmost point. The southern part of ~he Cordillera Oriental is generally low and poorly known. Numerous small paramo "is lands" alternate with humid Andean forest along the crestline from south to north: e.g. Picos de la Fragua , Cerro Punta, Miraflores, C. Paramillo, C. Neiva and the highest island Cerro Leiva (3520 m). The Paso de las Cruces depression (15002000 m) is the lowermost pass across the Cordillera Oriental and is considered as an important pathway for the exchange of subandean and warm-tropical flora elements . The Paramo de Sumapaz and the Sierra Nevada del Cocuy and surrounding paramos are the main paramo islands above the 3500 m contourline. ·smaller paramo islands are found on a parallel line to the NNE and include e.g . the paramos NW of Neusa, those E' of Arcabuco and Villa de Leiva , the Paramo de la Rusia, and its northern extension the Paramo de Guantiva. Further to the north are the paramo islands of Almorzadero, Santurban-Romeral, Cachira and Jurisdicciones. On the Venezuelan border the island of Tama is an eastern extension of the Santurban paramos. Cerro Mina, NE of Ocana, probably carries the northernmost paramo of the Cordillera Oriental. The_ study area is located above the upper Andean forest line (c. 3300-3400 m;

13 range 3000-3500 m) and reaches up to the nival belt (c. 4800 m). The central ranges of the study area include some highland basins at an altitude of 2500-2600 m, e.g. the Sabana de Bogota and the Sogamosa-Duitama high plain. At present a permanent snowcap is found only on the high peaks of the Sierra Nevada del Cocuy. The recent snowcap is about at 4800 m, but glaciers reach as far down as 4400 m. Van der Hammen et al. (1981) charted the retreat of the snowline in this area since 1938. Seasonal snow at lower elevations is. rare, but is reported occasionally. Peaks in the Sierra Nevada del Cocuy are higher than 4500 m, and some reach above 5000 m. The Ritacuba (5493 m) is the highest peak of the Cordillera Oriental. The Nevada de Sumapaz ~pproximately 4250 m) and its surrounding paramos mark the southern boundary of the study area (3°55'N). The summit of the Almorzadero (approximately 4375 m) is the northern limit of the study area (7°00'N), which measures about 450 km 2 N- S by air, but varies considerably in width (25-75 km). Taking into consideration that the paramos are "islands" of various sizes, the total area under discussion measures about 10,000 km 2 • The study area belongs to four "Departamentos" (Meta, Cundinamarca, Boyaca, Santander) and two "Intendencias" (Arauca, Casanare). For the boundaries of these political units reference is made to the "Atlas de Colombia" (3rd edition) and to the topographic maps (1:100,000 and 1:25,000), edited by the Institute Geografico "Agustin Codazzi", Bogota. Geology While marine sediments were formed in the northern Andean geosyncline during most of the Cretaceous, continental sedimentation started around the Cretaceous-Tertiary transition. During the Upper Tertiary the Cretaceous and older Tertiary sediments became strongly folded and faulted, and finally the study area was uplifted to its present elevation. This probably happened during the early Pliocene. According to the available geological maps (e.g. Arango et al., 1976) the greater part of the study area consits of Cretaceous sedimentary rocks, mainly sandstones and some shales. These include the older Villeta group, resp. formations F6meque, Une, Chipaque (Hauterivien-Cenomanian) and the Guadalupe group, resp. formations Raizal, Pleaners, Tierna-Labor (Turonian - lower Maestrichtian). The northern part of the study area mainly consists of Palaeozoic and locally of Jurassic and Cretaceous sedimentary rocks. Here and there igneous rocks are present. In the southern paramos near Bogota one finds outcrops of lower Tertiary age (Guaduas, Cacho and Bogota formations) and Palaeozoic (partly calcareous) bedrock (Quetame, Farallones de Medina, Paramo de Palacio, Nevado de Sumapaz). Useful pertinent information is provided by Hettner (1892), Burgi (1957), Irving (1971) and Me Laughlin & Arce H. (1971). The type and age of the rocks in the paramos visited is given below, mainly based on the geological maps obtained from Ingeominas; Bogota, for which the help of Dr. A. Alvarez-Osejo and Dr. H. Duque-Caro is gratefully acknowledged. Paramo de Sumapaz: Mainly Cretaceous sandstone (Villeta and Guadalupe groups). On the eastern border limestones and lutite,s of the precretaceous Clarin group. The boundary between the two formations runs across the Laguna El Nevado and E~of the Laguna Sitiales. Numerous fossil tabulate reefcorral species of Chaetetes (det. Dr. G. de Groot, Leiden) present in the calcareous rocks of the Nevado de Sumapaz suggest a carboniferous age. A collection of marine fossils collected with Mr. L. Carvajal was deposited in the museum of Ingeominas, Bogota. The mountains E of the Chisaca lakes are of Lower Tertiary age.

14 Paramo de Cruz Verde, Paramo de Palacio-Chuza, Paramo de Guasca, Paramos NW of ·Neusa : Sedimentary rocks of Lower Tertiary (Palaeocene to Oligocene) and Upper Cretaceous (Albian-Maestrichtian) age : e.g . Guadalupe group. Sandstones are predominant . A local limestone in the Paramo de Palacio is being mined. Paramo de Tota and surroundings: Cretaceous sedimentary rocks are present in most paramos. Upper Cretaceous (Albian-Maestrichtian} sandstones in the vicinity of the Paramo de La Sarna extend to the W. Locally, N and NW of the Lake Tota, there are Tertiary outcrops . Sedimentary rocks of Berriasian to Aptian age are found E of the headwaters of Rio Cusiana. Paramo de la Rusia: The triassi c to Jurassic sedimentary rocks consisting of reddish sandstone and ' conglomerates,mainly belong to the Giron formation. The slopes inmediately W o ~ Duitama consist of Tertiary rocks . Paramo de Guantiva (southern part) Reddish sandstones , lutites and conglomerates of the Giron formation are present :in the southern part, including the headwaters of Q. Minas . The Cerro Pan d'e Azucar consists of Palaeozoic (Devonian-PermianY gneis and granites. Wand NW · of this peak is an area with intrusive and extrusive rocks of Triassic:-Jurassic age. A narrow zone of (Lower} Cretaceous sandstone is found N of the Pan d'Azucar . Paramo de Pisva and Chita: Tertiary rocks on the Chicamocha side of the divide are bordered by a narrow zone of Upper Cretaceous sandstone striking N. The lowermost perhumid paramos of the Orinoco drainage oas·in consist of Lower Cretaceous oedrock (Triassic-Aptian) . Sierra Nevada del Cocuy: The wes·tern dips·lope of this range consists of Cocuy quart zite (I:ettner I 892 ; Notestein & King, 1932) of Lower Cretaceous (Berriassian-Aptian) age. Near Patio Bolos lutites and calcareous layers were found with numerous plant fossils. A collection was deposited in the Museum of Ingeominas, Bogota. Paramo del Almorzadero: Fieldstudies were only made in which mainly consists of rocks formation . The greater part of age and consists of sandstones

the southern calcareous part including the summit belonging to the Low Cretaceous Rosa Blanca the Paramo del Almorzadero is of Upper Jurassic and conglomerates of the Giron formation.

Geomorphology Though the paramo landscape was repeatedly glaciated during the Pleistocene (e . g. Vander Hammen 1974 , 1979 and in numerous other publications), at present a snowcape is only present in the Sierra Nevada del Cocuy . During the Neoglaciation the snowline reached as low as 4250-4400 m in the Cocuy area, and the ice covered the area of the present superparamo (Fig . 9) , which then was located at a lower elevation. Steep ridges and crests as high as 4500 m remained free of snow and ice (Vander Hammen et al. , 1981). At present these are overgrown with open CaZamagrostis bunches and EspeZetia stem rosettes, whereas moraines at the same elevation near the snowline are practically devoid of

15 vegetation. Gonzalez et al. (1965) and Van der Hammen et al. (1981) studied the glacial sequence and environmental history and recognized at least five (possibly six) drift bodies, all of which of Last Glacial (Fuquenian) and Holocene (Neoglacial) age. During Neoglacial times a minor ice area must have been present on the Nevado de Sumapaz (Vander Hammen 1979a; Cleef et al . , in press). Various glacial features are found everywhere in the paramo belt, but they become less distinct near the forest line. The lower paramos longer remained free of ice and thus were longer subjected to weathering and erosion than the higher ones. As a result of glacial events various glacial and periglacial features, like moraines , boggy U-shaped valleys, tills , cirques, fluvioglacial deposits, tarns and glacial lakes behind moraine ramparts, polished bedrocks, roche moutonnee, erratic rocks, etc . are common features. Oppenheim (1940). gave a geomorphological description of the glacial evidence in the Paramo de Sumapaz. For the Sierra Nevada del Cocuy geomorphological descriptions were presented by Gonzalez et al. (1965) and Vander Hammen et al. (1981); the latter also presented an photographic map of the glacial morphological features. Contributions on glacial and periglacial morphology of the Venezuelan paramos of the Sierra Nevada de Herida were made by Schubert (1979). From 3600 m up to the snowline he observed needle ice, micro terrassettes , sorted and non-sorted stripes, sorted polygons and circles (structure soils, sensu Troll 1958) and an abundance of screes . Furrer & Graf (1978) studied glacial and periglacial phenomena in the superparamos of Ecuador. They illustrated the marked increase in height and width of the superparamo zone in southern direction from the volcanoes of Cayambe, to the Cotopaxi and the Chimborazo. Within the study area frost heaving is most common on bare ground in the superparamo of the Sierra Nevada del Cocuy. Less evidence was obtained in the superparamo of the Almorzadero and the Nevado de Sumapaz , due to the fact , that the corresponding lo.w er superparamos have a relatively dense vegetation cover . Permafrost, common in arctic-alpine areas, seems to be almost absent in equatorial mountains. Quantitative data on weathering processes and denudation rates in the paramos of the study area are not available. In limestone areas, most of which are limited in size (e . g . Nevado de Sumapaz, summit and southern slope of the Almorzadero) karst phenomena were observed such as poljes and dolines, lost rivers, ponores, caves, etc . Soils At the time of 路t he fieldwork (1972 - 73) , little was known on the nature and g ~nesis of the paramo soils. Local names were used by IGAC (1965) and Carrera et al . (1968) for the soi l s of the Rio Bogota drainage basin, and descriptions and chemical analyses of profiles were presented . Names used in relation to soils of the paramos were e.g. "associaci6n paramo" resp. "asociaci6n ParamoUsme-Guasca". In view of the scanty knowledge and the few publications available , it was decided to describe as simple as possible a number of soil scharacteristics that are of importance for the vegetation. The following soil features were considered in each of the releves. 1. The pH in the top soil, at a depth of about 10 em (see introduction). 2. The lithologic composition (-texture) of the upper soil layer (A) (gravel , sand , silt , clay peat, gyttja). 3. Thickness of A-layer. 4. Colour of A-layer (with colour chart) .

These are ~entioned in the Samples were collected for of the soil in relation to project that includes also Central.

description of the communLtLes resp. plant associations. chemical and physical analyses. More detailed studies vegetation are now being made as part of the ECOANDESthe paramos of the Sumapaz area and of the Cordillera

Pedological data have beeri published by various authors and various classification systems (FAO, USDA, ORSTOM) are available. In this context only data will be mentioned, that have a direct bearing on the study area. Faivre (in Duchaufour, 1977) described a zonal soil under zonal CaZamagrostis effusa - EspeZetia paramo on a moderately steep slope at 3700 m in the Paramo de Chisaca . This soil is classified as "alpine ranker" in the French classification system, as a "humic cambisol" in the FAO classification and as a "lithic humitropept" in the US classification system. The A0 of 30 em consists for about 75% of organic matter and the low C/N ratio (of IS) indicates its origin in a vegetation rich in grasses. Schnetter et al. (1976) determined a number of pedological characteristics in relation to vegetation in the Paramo de Cruz Verde, E of Bogota . They found similar values, but also differences in C/N ratio in the dry season and the rainy seasons. C/N ratio varied under Calamagrostis effusa - bunchgrass paramo from 13 to 25 . N increases in the dry season, while C decreases. C/N under DipZostephium revoZutum shrub varied from 21 to 26. Sturm (1978I presented some observations on soil flora and fauna and on decompos-ition processes in the Paramo de Monserrate, E of Bogota. He summarized the results路 of previous pedological studies in the par amos near Bogota and elsewhere in the paramos of the northern Andes. Paramo soils (of the lowermost part of th.e paramo oelt) nave in common: 1. relatively moderately to highly acid soils nad correspondingly low Ca lavels; 2. hi'gR:er water capacity; 3 . low free P-content; 4 . relatively high content of K and N and reduced uptake of these elements by plants; 5. higfier organic content than 10% in the toplayer; 6. hardly or no "podzolic" features (cryptopodzolic or andopodzolic) . Soils on limestone bedrock, e.g. On the superhumid Nevado de Sumapaz, have dark brownish clayey profiles with about the same pH values as in the superparamo of the Sierra Nevada del Cocuy. At first sight, the calcareous nature seems to have little effect due to the humidity. Except for epilithic vegetation, there is hardly any botanical indication of the presence of calcareous parent rock. An important observation is that many soils in the higher areas of the Cordillera Oriental contain volcanic ash from eruptions in the Cordillera Central, which were mainly deposited in .the past 44,000 years (see e . g. Correal & Van der Hammen, 1977; Van der Hammen 1978. Schreve Brinkman; 1978, and Van der Hammen et al., 1980). In the Andean forest zone the ash added to the original surface (volcanic ashes, their weathering products, locally colluvial material and humus) may be as high as 2 meters or more, while 1.5 m is common. In the paramo the thickness of deposited material and (paleo)soils together rarely exceeds I m, but is generally thinner (Fig. 84}. The upper recent soil is very dark to black, due to a high percentage of humus (see above: "black paramo soils") . The deposition of the ashes causes that in many places with concave topography the original rock or soil cannot be reached by the roots, and hardly effects the vegetation (except when the added material is thin). Ih general, many soils in the paramos are inceptisols, which are slightly developed and relatively young; examples are orthents (alpine rankers), vitrandepts (vitrisols}, cryandepts (andosols), and others (possibly pseudo~

17 alpine rankers, rendzines (?), calcimorf soils, e tc.). Histosols (hydromorphic soils; gley, pseudogley) occur in very wet paramos, in peatbogs, swamps and mires.

Climate Due to its geographical location on the northern hemisphere near the equator and at high altitude, the paramo climate in the study area is of the humic tropical diurnal type, cold at night and cool in the day time. It is classified as Csw (or Cws) in the Koppen system (see discussion in Eidt, 1968). In contrast to the climate in the southern puna, the paramo climate is bas ically humid. Lauer and Troll (in Lauer, 1979) reported 10-12 humid months. But the study area contains also dry paramos with only 8 to almost 9 humid months, which in the classification of Lauer & Troll are ranked as moist puna (7-10 humid months). Information on the climate in the study area is scarce and is only available for some places near Bogota and for the Paramo de Berlin (Santander) at 3230 m. Precipitation has been measured, especially in the southern part of the study area, but records are scarce or absent for the northern part . Meteorological data were obtained from the annual reports by - Empresa de Acueducto y Alc"a ntarillado de Bogota, D. E.: Boletin Informative Hidrometeorol6gico. - Corpor aci6n aut6noma regional de la Sabana de Bogota y los valles de Ubate y Chiquinquira (CAR) : Boletin estadistico de Hidrologia y Meteorologia. - Servicio Colombiano de Meteorologia e Hidrologfa: Boletin Climatol6gico Mensual and Anuario Meteorol6gico. As to the paramo climate in the study area, a number of climatic factors will be considered, the most important of which are precipitation and temperature . Some measurements were made on speed and direction of wind, cloudiness/sunshine, radiation , evaporation, relative humidity, and dev1. The dependence of Bogota on water from the paramos, has been conducive to the abundance of pluviometric data for the southern paramos . Precipitation data were used for constructing climate diagrams. Extrapolation has been applied to arrive at a general idea of climate. In contrast to Eidt (1968), a mean annual temperature of 0° C was assumed at 4800 m (climatic snowline) and a mean lap of 0.6°C for every 100 m of altitude. This method was preferred, as the paramo belt is close to the nival zone . Thus calculated temperatures (T) are about 1.2°C lower than the values obtained with the Eid t formula: T = 30 - 6 H, where H is the height in kiQ.. This does not basicatly affect the shape of the presented diagrams . The calculated temperatures are indicated with an asterisk and a broken line in the diagrams of Fig. 3. This value of 0.6°C/100 m is corroborated by calculations by Van der Hammen & Gonzales (1960a) in Cundinamarca (2/30/100 m) and by meas urements during the ECOANDES transect study in the Buritaca trail , Sierra Nevada de S. Marta (0.56° C/100 m for the interval 1500-3300 m). Snow (1976) mentioned a temperature decrease of 7°C/km, resp. 6°C/km between 5000 to 4000 and 4000 to 3000 m in the Colombian Andes. Unlike for higher latitudes, the mean annual temperatures near the Equator thus can be easily approximated and plotted in diagrams. These have been constructed for a number of selected puv iometric stations in the paramo belt, in the vicinity of which field work was carried out (Fig. 3). Most precipitation values in the diagrams are above the temperatures curve during all the months of the year. Only in the

18 driest paramos a short period of waterdeficit may occur during one or two months, Werger (1973) summed up some restrictions for the application of climate diagrams, but for the scope of this study the diagrams are useful, especially for an ecological understanding of the different· paramo vegetation types. For comparison, a typical dry puna diagram (Fig . 3p) is presented from Pampa Galeras in SW Peru as based on Tovar Serpa (1973). The zonal puna vegetation there consists of spaced bunchgrasses of Festuca associated with Stipa . In wet depressions there are cushionbogs with Ptantago rigida and Distichia muscoides . About 35 out of approximately 150 vascular species in that area are also present in the Colombian paramos. For the study area some values of meteorological factors given below have been obtained from data compiled by the Colombian services mentioned before . As a matter of fact, different combinations of these factors head to different paramo climates . Data for the superparamo are not available. Precipitation Annual precipitation rates in the study area vary between 700 and 3000 mm . The highest precipitation with annual values up to about 3000 mm is found along the wet upper forest line on the humid side of the Cordillera (Figs . 3f and 4). With increasing elevation the precipitation rate drops (Figs .• 3d,e,k; 4). The lowest values are from dry leeward subparamos (Fig . 3a,i,m). There is one annual maximum of precipitation near the upper forestline on the wet side of the mountains, but there are two maxima on the dry side, Near the crestline intermediate conditions prevail (Fig. 3c,d,j,k,o). Weischet (1969) reported on the character of the precipitation max~ma in the Colombian Andes (including the southern part of the study area) . Temperature Mean annual temperatures in the paramo belt vary from 13-14° C to 0° C. The precise position of the upper forest line is supposed to depend on the complex interrelation between temperature and moisture. Slight differences are found in the mean annual temperatures at equal elevation on the humid and the dry side of the Cordillera Central, and this may explain part of the asymmetrical distr~bution of plant species (Vander Hammen et al . , ECOANDES report, in prep.). On the basis of the number of days with nightfrost and altitude, Lauer (1979a, fig . 9) depicted the position of the humid equatorial paramos intermediate b_etween Mexican and Peruvian high volcanoes. Cloudiness & drizzle Statistics on cloudiness are practically not available for the paramos in the study area. Cloudiness is highest in the wet season and this generally coincides with higher moisture conditions , as prevailing on the wet side of the mountains. Cloudiness maxima can be positively correlated with the presence of the forest line condensation belt and the upper condensation zone . In the early morning the paramos are generally free of clouds, but soon these rise from lower parts up to the paramo belt, which in the afternoon is mostly cloud covered and submitted to drizzle ("paramitos") and rain . According to Sturm (1978) this drizzle is practically not pluviometrically recorded . Much of the drizzle is intercepted by the numerous small leaves of woody species, as indicated by thick layers of pendulous epiphytic bryophytes dependent on atmospheric moisture . Interception

19 rates are supposed to be considerably high. Only few observations have been made on this phenomenon in tropical mountain vegetation (e.g. Kerfoot 1968; Vander Hammen et al.,in prep.). Pertinent data for the study area are lacking. Sunshine Duration of sunshine (in hours) is monthly recorded in a number of paramos near Bogota. For example, in the lowermost bamboo paramo or wet upper Andean forest of Chingaza and Chuza were recorded about 773 to 972 hours of sunshine in 1971, against 1432 hours in La Regadera at 3050 m in the dry valley between Usme and Chisaca and 1473 hours at the Represa de Neusa at about 3100 m. The two last stations are located in the upper Andean forest belt. The bamboo-bunchgrassparamo station Palacio-Guasca at 3760 m recorded an annual mean of 1080 (9851127) hours of sunshine from 1972 to 1974. Radiation Radiation increases with elevation and is highest in dry tropical high mountains. Ultraviolet waves contribute more at these high altitudes than at sea level . Intensity of radiation is controlled by frequent fog, and contrary to summer conditions in alpine belts at higher latitudes, the duration of radiation is limited to 12 hours per day in the paramos in the dry season. Incoming radiation is mainly converted into heat by the soil surface and the plantcover. Part of it is reflected by plants, which have developed various protection and/or reflecting structures: e.g. several types of adpressed indumentum, silvery leaves, brittle brilliant leaves, brownish-glaucous o~ reddish leaves. Apparently correlated with elevation and climate, an array of different morphological structures was observed, which will be dealt with in detail in future studies. Nightly long wave (re-)radiation is strongest under. clear skies in the dry high paramo, and surface cooling causes nightfrosts. Radiation is quantified in the study area as follows: -Paramo de Cruz Verde at 3480 m: 0.18-0.51 cal. cm 2 . min. on Nov. 5, 1971 under clouded sky between 10 a.m. and 4 p.m. (Schnetter et al., 1976) - Represa del Neusa at 3100 m: yearly average 345 (129-629) cal. em 2 /day. For 1969 120.564 cal. em 2 were recorded. Evaporation Evaporation records are scarce in the study area. The annual mean as deduced irofll the data of different stations J;lear Bogota is about 400-600 mm in the lower baÂ˘boo paramo and 700 - 1000 mm in the lower bunchgrass paramos. In the extremely dry Paramo de Berlin near Bucaramanga, annual evaporation varies even between 1200 and 1400 mm (1973-1974). Relative humidity Mean values of relative humidity are usually highest in the lower paramos and vary from 10 to 30 and up to 100%. Condensation belts are characterized by persistence of fog, and, consequently, by permanently high levels of relative humidity .

20 Wind Wind is generally strongest in the highest parts , where wind action on plants can be observed . Local diurnal upslope and downslope compensation winds seem to be predominant. N-E tradewinds are active most of the year . Near the wet and clouded upper forestline the windflow is slight : only about 1 - 2 m. sec (Chuza ; Chingaza stations) . Stormy upslope compensation winds seem to be an exception . We only experienced these during the night and early morning on e . g . Febr . 25 , 1972 at 3700 m near Belen and on March I , 1973 at 4300 min the Paramo de C6ncavo , Sierra Nevada del Cocuy. Condensation belts Since the study of precipitation in relation to elevation in the Colombian ~ndes by Weischet (1969), later confirmed by Guhl (1974) , Lauer (1979) paid atte~ tion to the unequal spatial distribution of humidity in the Mexican mountains and in the Ecuadorian Andes . Condensation zones have also been recognized in the study area , especially on the wet side of the mountains: I) the forestline condensation zone (or "2a Cintur6n de nubes ecuatoriales" of Guhl 1974) , and 2) the upper condensation belt (or Guhl's "3a Cintur6n de nubes ecuatoriales") in the lowermost superparamo between 4100 and 4300 m. Condensation zones are characterized by high moisture conditions , i . e . higher precipitation and relative humidity , more cloudiness and fog , and reduced sunshine , radiation , windspeed , and evaporation . In the study area also the presence of woody plants in zonal vegetation with larger leaves , and a marked increase in the bryophyte cover are characteristic . The daily temperature amplitude is less extreme than outside the condensation zone and is indicated as oligothermic by e . g . Troll (1968) . It allows the growth of woody species at elevations above 4000 m. Gradstein et al . (1977), Cleef (1978) and Cuatrecasas & Clee拢 (1978) pointed to ~he botanical richness of condensation zones , especially the uppermost one. It is assumed that such limited areas of favourable temperature and moisture conditions must have been of fundamental importance to the survival of a large number of hygrophytic species during arid (and cold) Pleistocenic peri~ods . According to Weischet (1969) and this is confirmed by the precipitation data for the study area, the rainfall decreases with the height in the paramo belt . The precipitation maximum appears to be located near the wet upper forest line (Fig. 3f,3g , 4) . Altitudinal positions and temperature and moisture characteristics of condensation zones will be quantified in the future as part of the current ECOANDES project . At this moment 路 mainly physiognomical and floristic evidence is available in regard to the condensation zones in the study area . Meso- and microclimate directly affecting plant growth have been studied by Schnetter et al . (1976) , Sturm (1978) and Rangel et al . (in prep . ) . The last author collected these in different altitudinal zones . Interesting microclimatic studies demonstrating the importance of rosettes and tussocks in paramo environment were carried out in the Venezuelan Merida paramos by Vares~hi (1953) , Smith (1974) , Larcher (1975) , Hedberg & Hedberg (1979), Monasterio (1979) and Az6car & Monasterio (1979) . The last mentioned authors and Walter & Medina (1969) studied Polylepis sericea dwarfforest . Hedberg & Hedberg (1979) measured daily temperature variation in Plantago rigida bog a~d in Hypericum Zaricifolium shrub .

21 Paramo flora The ~eotropical paramo flora has been studied since its first plants were described by von Humboldt & Bonpland in 1805. In the course of the last century contributions were made by Mutis, Triana, Weddell, Mitten, Hampe, Spruce, Nylander, and numerous other botanists. In this century and up to the present many new taxa of the paramo flora have been bescribed and many taxonomists actively study thi9/rich flora. Botanical exploration of the paramos has not yet been completed and it is to be expected that still many new endemic taxa will be described in the future. Obviously, continued botanical exploration of the paramos will also contribute to our knowledge of plantgeography and of natural resources. Local regional and "national" checklists, catalogues and floras have advanced the study of paramo plants. However, a systematic treatment within the framework of a flora project covering most neotropical paramos, at least fron northern Peru (Chachapoyas) up to Costa Rica and the Cordillera de la Costa, Venezuela, is the optimal approach and deserves attention. An attempt will be made to review the present taxonomical knowledge of the major taxonomic groups of the paramo flora. Vascular plants The vascular paramo flora is well known in comparison with other groups as bryophytes, lichens, algae and fungi. More than 300 native vascular genera are present in the paramos of the northern Andes. About 260 of them are found in the paramo belt of the Colombian Cordillera Oriental, an area which contains about 700 species (Cleef 1979a; 'lan der Hannnen & Cleef, in press). Together with the flora of the puna of northern Argentina (Cabrera 1958), the vascular flura of the study area belongs to the richest in genera and species of the high mountains of the world. Fig. 5 shows the qualitative and quantitative composition of the vascular paramo flora of the study area for families and genera. For comparison, similar data have been included for the Argentinan puna (Cabrera 1958), the "afro-alpine" belt on the equatorial East African Mountains (Hedberg 1965), and for the "tropic-alpine" belt of Mt. Wilhelm (4510 m), Papua New Guinea (J.M.B. Smith 1977). Only the families are shown that are present in the paramos of the study area. As in other temperate areas, the Compositae and Gramineae are represented by far the most genera. The tropical character is proved demonstrated by the presence of numerous genera of the Orchidaceae, Melastomataceae, Piperaceae, Bromeliaceae, Xyridaceae, etc. Bromeliaceae are almost limited to the neotropics and Melastomataceae only here are adapted to supra forest-line habitats. Among others, J. Cuatrecasas contributed to the knowledge of the vascular paramo flora in numerous publications. Soon forthcoming is his monographic treatment of the Espeletiinae (Heliantheae, Compositae), species of which are undoubtedly most characteristic for the north Andean paramos. A number of vascular genera is in need of systematic study or revision. Alphabetically according to family these are; Ilex, Callitriche, Arenaria, Hypochoeris, Hieracium, Senecio s.l . , Lucilia, Gynoxys, Draba, Carex, Eleocharis, Scirpus subgenus Isolepis, Gaultheria, Plutarchia, Gentianella, Halenia, Agrostis, Bromus, Calamagrostis, Festuca, Muhlenbergia, Poa, Altensteinia s.l. Lupinus, Lachemilla, Rubus, Hesperomeles, Ribes, Castilleja, Bartsia and Valeriana. For most of these genera cytologic research in combination with experimental breeding under controlled conditions is required to determine the exact systematic pos~t~on. Preliminary results of a cytologic inventory are promising (H. 't Hart, unpubl.; E.G . B. Kieft, unpubl.).

22 Mus c i The present knowledge of the moss flora of the paramos is illustrated by the checklist of paramo mosses from Vene zuela and Colombia by Griffin (in prep.), containing about 180 genera and 380 species. Acrocarpous mosses are prominent in the open par amo. Their abundance generally inc reases with altitude and aridity . The most common gene ra of the paramos include: Breut elia, Campy lopus (Florschutz & Florschutz-de Waard 1974, Frahm & Cl e ef, in prep.), Lept odontium, and Sphagnum. Species of Chor isodon t i um (Frahm & Cl ee f , in prep.), Racomit r ium crispulum and Rhacocar pus purpurascens abound esp e cially on the humid side of the mountains and within the reaches of the condensation belts . Kingiobryum is the only endemic genus des cribed from the paramos (Robinson 1967, Zander & Cleef , in press). The most recent work on Colombian moss e s is that of Robinson (1967) . In addition to checklists published for other tropical Andean countries , Florschutz-de Waard & Florschutz (1979) presented a list of Colombian moss species . Hepatica e In nearl y all altitudinal zones of the paramo belt, possibly the upper superparamo excepted, liverworts are conspicuous elements of the paramo vegetation, in some places even domina ting the vegetation . StephanielZa paraphy ZZina, and GongyZanthus liebmannianus are characteristic for the open dry zonal bunchgrass paramo and JamesonieZla rubr icaulis, Isotachis multiceps, Riccar dia spp. and Jensenia erythr opus for the (zonal ) bamboo paramo . Species of Ricardia mainl y abound in paramo bogs, mostly on decaying sphagnum or vascular cushionplants, but they are also common on peaty soil . Anastrophy llum spp., AdeZanthus lindenber gianus , Lepidozia macrocolea, Kurzia verrucosa, Leptoscyphus cleefii and species of PlagiochiZa are also common in boggy habitats. Together with mosses they play an important role in the succession of Sphagnum bogs , especially in the bamboo paramos . Symphyogyna sinuata is typical for tall Cyperaceae reedswamps containing species of Carex and Cyper us, Mar chantia pZi cata for the same Cyperaceae reedswamps, as well as for the different types of CaZamagr ostis Zigu Zata mire and Mantia springs. Isotachis s er ruZat a is practically the only species dominant in submerged communities in streams the high paramo . This species is also pr esent together with submerged brypphytes, associated with species of I soetes sect. Laeves in cold paramo lakes. Her bertus subdentatus and H. acantheZius cause the characteristic reddish hue t o the (lower) superparamo vegetation in the upper condensation zone of the Nevado de Sumapaz (Van Reenen, in press}. Gradstein et al. (1977) reported 62 genera of liverworts native to the Colombian paramos. From this list should be omitted Arachniopsis, PaZZavicinia and Leucosarmentum ; specimens brought then to these genera are now considere d to belong to resp . TeZaranea, Jensenia and Bonneria . Among the genera to be added to this list are: Andr ewsianthus, EopZeurozia and Nardia. During the last 10 years contributions to the knowledge of Colombian liverworts were made by Dr. S.R. Gradstein and his students (Division of Cryptogams, Utrecht University). Revisions were prepared for the high Andean species of RaduZa (Jans 1979), Jensenia (Vander Gronde 1980), FruZZania subg . Chonanthelia (Haarbrink, in press) , and Herber tus (Van Reenen , in press). Lichenes About 50 genera of macrolichens have been recorded for the Colombian paramos (Sipman & Aguirre , in prep.). Included a re Neuropogon and UmbiZicaria

which had not been previously reported for Colombia . According to H. J . M. Sipman (pers . comm . ) , part of the lichen flora is of tropical origin , e.g . Heterodermia~ Cora~ Stictaceae and a number of parmeliaceous genera; most genera are wide-temperate in distribution , e . g. Stereocaulon~ Thamnolia . Holarctic (e . g . Cetraria~ Alectoria, Bryorial and genera of australantarctic affinity (e . g . Cladia, Neuropogon, PseudocyphellariaJ are present in more or less equal generic proportions .. Remarkable is the amp hi -pacific distribution , e . g . in Anzia, Glossodium, Oropogon. Since Nylander (1863) , few systematic studies were made on paramo lichens . During the last years , however, the attention of lichenologists for the neotropical mountains increased considerably . For the Colombian Andes and more in particular the present study area , Sipman & Cleef (1979) reported on Cladonia subgenus Cladina . Sipman (1980) studied high Andean members of the Everniastrum complex , and in addition to several new species he described a new and apparently endemic genus Cetrariastrum. Stereocaulon and Leprocaulon have been studied by Boekhout (in prep . ) . A checklist of Colombian macrolichens is being prepared by Sipman & Hekking . Algae Algae are abundantly present in het humid paramos of the study area .· Conspicuous is the presence of lilac Aphanocapsa gervillei (Hass.) Rabenh. (Cyanophyta) in humid glaciersand in the superparamo of the Sierra Nevada del Cocuy (det . Dr . G. H. Schwabe) . This pioneer species had been recorded already for the high Alps and Surtsey (G . H. Schwabe , in litt . ) . Dr . A. J . Dop (formerly Free University of Amsterdam) identified part of the collected fresh-water algae , some of which are of interest for (paleo-)ecological studies . Three main groups were reported by Dop (in litt . ): I . Cyanophytae : Haptophytic and pleustophytic Stigonema spp . (3440-4335 m): e . g. Stigonema ocellatum Thuret , S. tomentosum (Klitz . ) Hieron.; S. f lexuo sum W. & G. S . West ; Nostoc sp . 2 . Rhodophytae : Haptophytic Bah•ac•hospermum sp . (3450-3800 m) in running and stagnant water . 3 . Chlorophytae : predominantly members of the Conjugales and (cf.) Microspora, Mou{Jeotia, Spirogyra and Zygnema are the most common genera of the Conjugales. Generally they form thick masses floating just below the surface in pools and streams . Van Geel & Van der Hammen (1978) reported on fossil Zygnemataceae , Oedogoniaceae and Desmidiaceae in Pleistocene and Holocene lake sediments ~n the high Colombian Cordillera Oriental . Chaetophora pissiformis was fou~d in a paramo stream at 3460 m (Roth . ) C. A. Agardh . Dr . Dop also identified Vaucheria cf . dichotoma (Xanthophyceae) , from paramo streams and seepages . Diatoms were found associated with or dominant in pioneer habitats , especially Navicula sp . Three characeous species (Nitella acuminata A. Braun ex Wallm . , N. clavata Kutz. em . R. D. Wood , N. flexilis (L.) C. Agardh) were collected in the study area; probably they are most common in deep paramo lakes . In summary , it is clear that a systematic inventory of algae and other limnological research has only just started in the paramos . On this taxonomic group West (1914) is the main reference for the study area . In addition , for Venezuelan paramo lakes reference is made to Gessner (1955) and Heibezahn & Cressa (1979) .

Macro fungi According to Dennis (1970) rather few endemic genera of macrofungi are known from the Venezuelan paramos. Most of them were found in bamboo habitats . It is possible that the same holds true for the Colombian paramos , which are generally more humid with bamboo as a common feature . Though some haphaz ard observations on macrofungi we re maded during the present study, most of them in boggy habitats ; e.g. ScuteZZinia spp. (Pezizales) with its bright red discs ; only little mate~ial was co llect ed and sent to Dr. K. Dumont (NY) for identification. Dumont et al. (1978) re centl y started with "Flor a de hongos de Colombia". A number of contributions have been published, mainly in Caldasia. Recently, Boekhout (in pre p.) collected macrofungi in the zonal bunchgrass paramo of the volcanoes S. Rosa and S. Isabel, from the forestlin e up to 4600 m, during .a n ECOANDES transe c t study in that area in 1980 . Species of licheniz e d Omphalina are most common on bare ground in the hi gh paramo . Lycoperdon sp. was frequ en-t there in grazed LachemiZZa orbiculata vegetation and also in the study area. Species of ScuteZZ inia and Cystoderma were collected . In conclusion, inventory of the macro fun gi had jus t startea in the Colombian paramos.

Phytogeography Phytogeographic as pects have already received special attention Ln some earlier papers (Cleef 197 8, 1979b ; Vander Hammen & Cl eef, in pre ss) . The main reason is that such studi e s on the phy to geographic relations of the paramo flora and vegetation may yield more qualitative and quantitative information , e.g. for an inventory of local and allochtonous elements (Cleef 1979b) . In connection with historical data (Van der Hammen 1979b van der Hammen.& Cleef , in press) these studies may shed more light on the origin of the early pa r amo flora (about 2 . 5- 3 millions of years ago),and on its successive enri chment by subsequent immigration, evolution, and speciation caused by the repeated fr agmentation and isolation of Pl e istocene paramo biota . Analysing the pre sent geographic~l distribution of the endemic vascular genera on the paramos of the Colombian Cordillera Orient a l the present author (Cleef 1979b) distinguished primarily be tween (local) tropical and (allochtonous) temperate components. The local t r o p i c a 1 component is subdivided into : - neotropical element dominated by genera with a tropica l-Andean distribution . The endemic paramo element is part of it . -wide tropical element defined as proper to cool, as well as to warm tropical areas of at least two continental regions, either America and Africa and Asia/Australia, or all three of them . Taxa belonging to this elements have a similar distribution in paramos and savannas . The allochtonous t e m p e r a t e component is subdivided into : - holarctic element , which comprises all kinds of northern immigrants , widely distributed in the temperate holarctic (e.g. Pleurozium schreberi) or restricted to cold arctic-alpine a reas (e . g . Alectori a). - austral-antarctic element, which is geographicall broadly defined (Cleef 1979b) . - wide temperate element , whose distribution extends to nearly all temperate and cold regions of the world . Finally , the (sub-)cosmopolitic element combines more or less the taxa wi th distribution areas of both the tropical and the temperate component .

25 In about 260 vascular genera Cleef (1979b) found equal proportions of the tropical and the tempe r ate component . -For the paramo element , the other neotropical element and the wide tropical element , the proportions are resp . about 8 , 33 , and 10% . The holarctic and aust r al-antarctic element are present in about the same proportions , resp . II and 9% ; the wide temperate element attains about 20% and the (sub-)cosmopolitic element about 8% . This subdivision into geographical flora elements has also been used for vascular paramo and fo r superparamo species in the study area (Van de r Hammen & Cleef , in press) it was further applied to the non-vascular paramo flora and to dominant taxa in the vegetation types of the study area in order to obtain a first impression of main geographic affinities . As a consequence of current monographic systematic studies , we know that high tropical mountains in America , Africa and Australasia have a considerable number of species of bryophytes and lichens in common . Genetic phytogeographic flora elements have not been recognized in our studies , because the precise areas of origin of many vascular and non-vascular genera of the paramo have not been well established .

Botanical exploration The history of scientific botany in the Colombian high Andes began in the early years of the last century , when Mutis and von Humboldt & Bonpland collected and described the first paramo plants in the vicinity of Santafe de Bogota in the "Virreynato de Nueva Granada", under Spanish government at that time . In the middle of the 19th century , collectors amongst others Purdie , Triana , Lindig and Kalbreyer were active . Since the first decennia of this century , collecting activities in the high parts of the Cordillera Oriental we r e strongly renewed , e . g . by Killip & Smith , Troll , Perez-Arbelaez , Cuatrecasas , Garcia- Barriga . During world-war II , members of the US Chinchona expedition , with Fosberg , Little jr ., Haught , Fassett and others , collected i n the par amos throughout the study area . In the years after the founding of the Herbaria Nacional Colombiano (1931) and the Instituto de Botanica of the Universidad Nacional (1938) headed by PerezArbelae z, the staff members substantially supported collecting activities in the paramos of the study area , e . g . H. Garcia-Barriga , J . Cuatrecasas , L. UribeUribe , L. E. Mora- Osejo , R. Jaramillo - Mejia , M. T. Murillo , J .M. Idrobo-Munoz , A. Fernandez-Perez , P . Pinto-Escobar , G. Huertas & L. Camargo , E. Forero Gonzalez , G. Lozano-Contreras , S. Diaz-Piedrahita , 0 . Rangel-Churio , J . AguirreCebaf los . Below follows a listing of the paramos of the Cordillera Oriental , where botanical explor ation not or hardly has been carried out : - paramos E of Neiva : Cordillera de los Picachos , - southe rn par t of the Paramo de Sumapaz , - the Farallones de Medina , - the paramos above Villa de Leiva , - the northern part of the Paramo de Guantiva , - the paramos between Pisva and Tota , - the paramos between Tama and the Cocuy , - the Cordillera de los Cobardes (if it supports paramos} , - the northe r nmost paramos of the Cordill e ra Oriental (N of the Ti bu p i peline) , - all wet forestline paramos .

26 For collecting localities of the present author , reference is made to Appendix 3 .

Paramo vegetation Previous investigations In the beginning of last century von Humboldt gave the first impression and scientific description of the paramo vegetation and its environment , based on his travels in the northern Andes . Cleef (1978) listed the authors of publications dealing with the ecology and vegetation of the neotropical paramos until 1975 . During the last 5 years , the interest in the paramos has strongly increased, as indicated bb the number of papers on its vegetation and ecology (mentioned i ~ Cleef , 1981 ) , by a special paramo session of the International Symposium of\ Tropical Ecology in Panama in March 1977 , and by the first Seminario del Media Ambiente Paramo , held in Novembe r 1978 in Merida , Venezuela (Salgado-Labouriau (ed . ) 1979) . With respect to the Colombian paramo vegetation , Dr . J . Cuatrecasas in 1934 presented the first plant - sociological data in his classic account : " Observaciones Geobotanicas en Colombia" . Contributions to the knowledge of the Colombian paramo vegetation were made by Fosberg (1944) and Cuatrecasas (1954 , 1958) , who proposed the altitudinal subdivision of the paramo belt. Further contributions were made by Cuatrecasas (1968) , Espinal & Montenegro (1963) , Vander Hammen & Gonzalez ( 1963), Lozano & Schnetter ( 1976) , Gradstein et al. ( 1977) , Cleef (1978, 1979a) , Sturm (1978) and Vander Hammen et al. (1981) . Important work was also done by staff and students of the Department of Biology (Universidad Nacional , Bogota) in fieldcourses , e . g . in the Paramo de Pisva (Rangel (ed . ) 1976) . These studies on paramo vegetation can be divided into two groups : (I) local studies : e . g . in the Paramo de Cruz Verde (Lozano & Schnetter 1976) , Monserrate (Sturm 1978) , and in the Parque Los Nevados , Cordillera Central (Cleef et al ., in press) . (2) regional studies , based on fieldwork in a geographically larger area of Colombian paramos . For example : Fosberg (1944) , Cuatrecasas (1954 , 1958 , 1968) and Cleef (1978 , 1979b , the present study) . The p'r esent study From November 1971 up to July 1973 fieldwork (sponsored by WOTRO) was carried out in the Colombian Cordillera Oriental between the Sierra Nevada del Cocuy and the Nevada de Sumapaz , and in March and April 1977 additional fieldwork was carried out in the Si erra Nevada del Cocuy (with R. JaramilloMejia & T. van der Hammen) , near Neusa , Cundinamarca (with S. Diaz-Piedrahita) and in the Paramo de Sumapaz in the Chisaca , Andabobos and Rabona areas (with T. van der Hammen) . In November 1978 the paramo vegetation of the southern slope of the Paramo del Almorzadero was studied (with J . Aguirre Ceballos & H. Hooghiemstra) and in the same month the zonal paramo vegetation was surveyed in the headwaters of the Quebrada Chuza and Rio Guandoque near Bogota during a phytosociological fieldcourse (for students , given in collaboration with staffmembers of the Universidad Nacional) . The present vegetation study covered 8 cross-sections or transects , shown on the map (Fig . 2) . In some of the paramos visited by the author at that time no previous botanical exploration had been carried out . These areas include the Nevada de Sumapaz (about 4250 m) and the headwaters of Rio Sitiales with many lakes ; the Pen a de

27 Arnical and surroundings, North of Vado Hondo and East of the Tota lake; the southern part of the Paramo de Guantiva, NW of Belen including the Pan de Azucar (4270 m), the highest peak; the Paramo C6ncavo and valley of the Quebrada Los Osos in the Sierra Nevada del Cocuy (with T. van der Hammen) and the calcareous summit area (4375 m) of the Paramo del Almorzadero. In the southern part of the Cordillera Oriental the Huila slope of Cerro Punta was explored up to the wet forest line (2760 m) just below the highest peak. The paramos studied in the Cordillera Oriental of Colombia thus extend from the Paramo del Almorzadero in the north to the Nevado de Sumapaz in the south. For the sake of comparison some additional trips were made to adjacent paramos in the northern Andes and Central Ame rica. Observations and phytosociological records were made in the paramos of the volcano Purace (1972, with A. Fernandez Perez) and in the Parque Los Nevados (ECOANDES project 1980) both located in the Cordillera Central of Colombia, and in the Sierra Nevada de S. Marta (ECOANDES project 1977). Some data were collected in the humid .s ubparamo in Costa Rica (1973 , with L. Fournier), in the dry subparamo on the Avila above Caracas (1977, with 0. Huber), and in the Venezuelan Sierra Nevada de Merida (1972, 1978). Also the "zacatonales" (grasslands), dominated by bunches of CaZamagro stis toZueensis (HBK) Trin. and Fes tuea toZueensi s HBK on the high Mexican volcanoes Popocatepetl and Iztaccihuatl, on the boundary of the tropics, were visited with C. Delgadillo M. (1973).

Morpholo gic a l characters of paramo vege tation Studies on the structure and texture of the vegetation of the Colombian Andes were already made in 1934 by Cuatrecasas. In fact, interest in the structure of the vegetation was first aroused in the tropical Andes by von Humboldt in the be ginning of l a st century. Later, e . g. Be ard (1955, 1973), Vare s chi (1966, 1980), Halle et al. (1978) and Roth (1980) made substantial contributions , mainly based on studies in the American tropics. Cuatrecasas (1934) in his classic study mainly follows Del Villar (1929). The socalled "simorfias" of Del Villar are based on the physiognomic concepts of von Humboldt and Grisebach. Cuatrecasas (1934, 1968) adapted these to the paramo vegetation of the study area, and thus distinghuished a number of basic forms. Some of the most characteristic are e . g . "caulirr6sula" and "cryptolignum". Woody monocaulous composite rosettes, e.g. "caulirr6sula", are only present in the equatorial high mountains of Africa and S. America, where they evolved independently by adaptive evolution. Textural characteristics studied by Cuatrecasas (1934, 1968) include: I) Leaf size. according to Raunkiaer (1916): - fl eptophyllous ( <. 25 mm2) ~ nanophyllous (25-225 mm2) - microphyllous 225-2025 mm2) - mesophyllous (2025-18.225 mm2) - macrophyllous (18.225-164.025 mm2) - megaphyllous ( )164.025 mm2) 2) Leaf consistency. Cuatrecasas (1934) divided this character into three classes: - sclerophyllous or coriaceous - subcoriaceous or cartilaginous - herbaceous 3) Leaf indumentation: a number of different xeromorphic characteristics were used: pubescent, villose, tomentose, lanate, hispidous,

28 pulverulent and scabrous; in addition, pubescent nerves or ciliate margins and the position of the indumentation on one or both sides of the leaves. , Occasionally the leaf colour was noted. 4) Other leaf conditions: grasses were subdivided into I) revolutifolious species, with inrolled leaves, determining zonal bunch grass paramos; 2) planifolious species, with flat leaves, predominant in the lower part of the superparamo (e.g. Poa, Agrostis f oliata ). Poa cf. pauaiflor a has complicated leaves. 5) Characteristics of the tomentum of young twigs. Cuatrecasas (1934) determined these morphological characters for each plant species and summarized the data in "biotypological spectra" . In conclusion he presented an altitudinal outline for climax-vegetation in all zones from tropical lowlands up to the snowline, both for the Cordillera Central and for the Cordillera Oriental of Colombia. For the latter , in the highest reaches of which the study area is situated, Cuatrecasas (l.c.) demonstrated the presence of predominantly macro- and mesophyllous subandean forests (" Ingion") at 1500 m up to nano- and leptophyllous subparamo thickets at 3400 m. The proportion of sclerophyllous leaves of these forests increases with altitude from 23 % in t he "Ingion" to 56% in the "Cor dietum" near Bogota (2650 m), to 80 % in the microphyllous "Wei nmannion" (2900-3100 m) and up to 100% in forestline thickets at about 3300. m. To define morphological characters reference is made to general concepts as recently summarized by Barkman (1979). Leafsize, however, follows the classic subdivision of Raunkiaer (1916) , which is not quite consistently quoted by Barkman (1979) as he adds the bryophyllous class (0-4 mm2) which is in fact a finer subdivision of the leptophyllous class. Comparison of the leaf size spectra becomes difficult as various authors applied different size classes, e.g. Vareschi (1966), Werger & Ellenbroek (1978) and Barkman (1979). Camerik & Werger (1981) studied l eaf sizes of the evergreen surrnnit veg.e tation of Itatiaia , Bra sil, and applied size classes that nearly coincide those of Raunkiaer for the lepto-, nano- and microphyllous categories. My results (Fig. 86) are directly comparable to those in studies on the tropical Andes by Cuatrecasas ( 1934), Grubb et a(. ( 1963), Lozano & Torres ( 1965, 1974), and Rangel & Aguirre (in prep.). For other textural characteristics , Cuatrecasas (1934) has been followed. In an earlier study (1978), I presented a summarized inve ntory of prominent paramo in relation to altitudinal zones. The present study provides more details for both the atmospherical dry and humid side of the Cordillera (Fig . 6), but the "life forms;' discussed in the earlier study are now called "growth forms" in agreement with the concepts e xplained by Barkman (1979). The present author believes, however, that life forms and growth forms in the high tropical mountains cannot be distinctly separat e d in a satisfactory way. Some authors even do not 路make distinction between them . Aspects of both growth form (morphological aspects) as well as life for~ (ecological aspects) are closely interwoven in the plants 路 of these habitats a.~d result in clearly distinct forms路. It is a matter of arbitrary emphasis to decide to call it growth form or life form. In the most fundamental morphological system _fnr waterplants (Luther, 1949) a distincti9n is made between: I) haptophytes, 2) rhizophytes, and 3) planophytes (includihg pleustophytes). Den Hartog & Segal (1964) is followed for outlining growth ~forms of vascular species in aquatic environment . Their system is based on that of Du Rietz (1921, 1930) and Luther (1949), and is worked out here for rhizophytes and pleustophytes. In absence of Podostemonaceae in our study area, haptophytes are only represented by benthic algae and bryophytes. _In" the paramo belt have been recogni zed: .:. rhizophytes: I) isoetids : Isoetes.s pp. ,, Li mosella australis

29 2) elodeids : Potamogeton spp . 3) myriophyllids : Myriophyllum elat inoides 4) callit r icheids is used instead of batrachiids , because native species of Ranuncu lus subg . Batrachium are virtually absent in the Neotropics . Species of Callitriche ~ Hydrocotyle ranunculoides and Elatine cf . chilensis may belong to this group . Species of the two last genera are also named amphiphytes by Iversen (1936) . -

pleustophyt~s :

Utricularia obtusa is the only species belonging to this (Ceratophyllum is absent in neotropical waterbodies) . 2) lemnids : Lemna minor~ Azolla filiculoides . I) ceratophyllids : group ~

The relation to the environmental conditions is also expressed by such terms as amphiphytes , helophytes and pleustophytes , which are also used in this paper . Physiognomical systems for defining paramo vegetation, e . g. by Fosberg (1967) and Mueller-Dombois & Ellenberg (1974) , will be worked out in future studies . An example of zonal lower paramo vegetation was given by Sturm (1978) . Following Raunkiaer's plant life forms (in the revised version of Ellenberg & Mueller-Dombois 1967) Sturm developed spectra for the Monserrate paramo at about 3230 m above Bogota: zonal dwarfshrub paramo is dominated by (sclero-)nanophanerophyta , and the lower grassparamo by caespitosa hemicryptophyta . Rosette species (nanophanerophyta) are prominent with a cover of 20-30% . Macrophanerophytes , geophytes , therophytes and thallophytes are scarce or absent . Paramo fauna An excellent general outline regarding the paramo fauna was recently published by Sturm ( 1978) . I t will not be attempted to list all species of animals in the study area , but a short outline of the most conspicuous groups will be given . Tropical American grasslands only support few endemic grazing vertebrates~) in comparison with those in tropical Africa . This also applies to the paramo belt of the study area , in which only two large herbivorous species of deer are known : Odocoileus virginianus goudotii Gayl & Gervais ("venado grande") and Mazama rufina bricenii Thomas ("venado soche") . These species are being hunted , and they have become rather scarce . Bears (Tremarctos ornatus (F . Cuvier)) mainly enter the paramos in the dry season . Their- diet here consists of the soft parts of bromeliaceous rosettes of Puya and Greigia. Another , but common omnivorous species hiding on screes and other rocky areas is Nasuella olivaceae (Gray) , known as "guache" (Cundinamarca/ Meta or "tinajo" (Boyaca) . This raccoon species was observed up to the boundary of the lower superparamo at 4300 m in the Sierra Nevada del Cocuy . Smal~ grazing vertebrates witha distinct impact on the pat~mo vegetation are common) e . g . the rodents as Sylvilagus brasiliensis meridens~s Thomas ("conejo") and Cavia poi>ceUus anolaimae J . A. Allen ("curl:") . Bylvi lagus is present everywhere up to 4600 m, judging from the excrements . Cavia is mainly restricted to paramo mires and Sphagnum bogs , where it forages mainly on sedges . Cavia is found between 2000 and 3800 m. Another rodent, Stictomys taczanowskii Thomas ("borugo" or "lap a") has only been observed in the lower p~rmos . Among the avifauna may be mentioned ducks , snipes , hummingbirds , and birds of prey (Olivares 1969 , 1973). Ducks (Anas spp . ) are common on the large paramo lakes , b ~generally in small numbers . Humming birds (Trochilidae) are present throughout the paramo belt up to 4300 m. They are common in shrubby paramo

* ) Data on vertebrates were kindly provided by Dr . Jorge Hernandez Camacho , head of the research division of INDERENA, Bogota .

30 vegetation, vLsLtLng the flowers of Espeletia, Senecio, Pyua, Castilleja and the red flowering species of Bartsia. It is possible that pollination of the purple-reddish and the yellow-greenish species of Bartsia is different. Reddish flowering sprecies of Bartsia pollinated by the hummingbird, seem to be predominant on the clouded side of the mountains, whereas mainly insect pollinated green-yellowish flowering species are predominant in the dry bunchgrass paramos Hedberg et al. (1979, 1980) studied the yellow and white to pink flowering species of Bartsia in the afro-alpine flora, but made no reference to bird pollination. Snakes a<e reported by Sturm (1978) from the subparamo. Lizard species are common in the atmospherical dry paramos up to about 4300 m. They are scarce in the bamboo paramos , however. Amphibians are common except in the superparamo; they are found in bogs, mires and on other humid and wet ground. They hide in rosettes of Bromeliaceae, in shrubs, under tussocks and in the dense mantle of marcescent dry leaves of the Espeletiinae. In many paramos the trout, Salmo gairdnerii , has been introduced. The ~ ffect of the pres ence of trouts on the paramo freshwater ecosystem is unknown ( to the author). Gastropods, especially Bulimulidae, are common in the zonal grass paramo, especially on humid thin soil (community 13a). Breure (1976 and pers.comm.) supposes that they feed on raw litter. Plekocheilus (Aeropictus ) succinoides (Petit) is the most common species in the study area. According to Breure (1976) the ssp. succinoides is found from the Sabana de Bogota (2600 m) up to about 3600 m, and the ssp. cleeforum in the high bamboo-bunchgrass paramo between 3800 and 4000 m in the Paramo de Sumapaz. Species of Bulimulidae were recently also collect ed up to about 4400 m in the humid lower superparamo (Breure & Eskens, in press; ECOANDES report 1980, in prep.). Small fresh-water bivalves are common in paramo lakes, in mire and under flush vegetation. Specimens were identified as Sphaerium lauricochae Philippi (det. J.G.J. Kuijper). Previously they were only known from high Andean lakes in Bolivia and Peru. Aquatic fauna further includes species of Gammarus and Hirudinae (leeches), which are common up to 4400 m. Butterflies are common in the paramos of the study area, but most of them are small and inconspicuous, except for Eupyra ducalis Maassen (det. Dr. R. de Jong, Leiden), which was commonly observed on the disc flowers of Espeletia spp. together with bumblebees. Ants (Formicoidea) only have been observed in the lowermost paramos mainly on the dry side of the mountains. Grasshoppers (Orthoptera) are locally common up to higher areas. Native species of cockroaches (Blattoidea, Dysdercus ) are common under stones and boulders up to 4500 m, together with small black beetles (Carabidae). The ecology of insects in alpine environments was studied by Mani (1962) and Franz (1980), and their conclusions may also apply to the study area. Worms (Lumbricida e) are common in humid paramo soils up to 4300 m. According to Sturm (1978) they are less important to the paramo ecosystem than they are to ecosystems in temperate areas. Among the mesofauna, Enchytraeidae are apparently most active in humic paramo soils. Interesting studies on the ecology of the paramo fauna in the study area, especially of invertebrates, were recently made by Sturm (1978, 1979) and Rangel & Bernal (1980). Janzen et al . (1976) studied insects by means of sweep samples along elevational transects in Venezuela and Costa Rica.

31 Land use and human impact 路shifting cultivation frequently in combination with stock farming is most common in the paramos of the study area. Most pf these agricultural activities are concentrated on the dry side of the mountains. The other side is less densely populated due to the high humidity. Most ranches ("finca/finquita ") are located in the subparamo, and they are of subeconomic size. The farmers, mainly from indian descendence, are very poor. The way in which they are selfsupporting is impressive and deser~e~ respect. Partly, as a result of their struggle for existence, native paramo shrub and timberline forests disappear at an alarming speed. Native timber (e.g. Polylepis ) is used for the construction of fenceposts, for ranches and as fuel. The walls of the highest located small ranches are still made from Espeletia-stems (e.g. Espeletia lopezii , E. grandiflora ) and these are thatched with Calamagr ostis effusa bunches. The highest dwellings just reach the lower grassparamo at 3500-3550 m, but on the dry side of the Sierra Nevada del Cocuy they are found locally up to 3950 m. This is exceptional for the Cordillera Oriental, out common in the Cordillera Central, e.g. in the Parque Los Nevados. Large-scale habitation and agricultural activities in the lower paramos are of recent time , and are believed to have begun after the arrival of the conquistadores. Originally, and before the Conques t, mos .t of the study area belonged to the territory of the Chibchas. The Laches and Tunebos tribes controlled the northern part of the study area; the latter still live here. The Sutagaos lived in the Paramo de Sumapaz. According to Dr. G. Correal-U. (pers. comm .), in pre-Colombian times the natives visited the highest peaks only to bury their prominent dead. Legends are related to sacred places as the Lagunas de Siecha in the Paramo de Palacio and the Filo Sitiales in the Paramo de Sumapaz. The names of these paramos indicate the nearness to heaven. With r egard to crop and herding, some remarks will be made with respect to the impact of these ac~ivities on the vegetation of the study area. The main crop is potatoes, with two crops per year. One of the products are the delicious small tubercules of the race "papa criolla". Onions, Tropaeolum tuberosum R. & P. ("cubios"), Oxalis tuoerosa Savign.("ibias") and aromatic weeds are . grown too. Tubers are the most important f~od source for all Andean people (Barclay 1962, Murra 1979 , Wagner 1979, Troll 1968). Chunu, a technique to preserve tubers by dehydration, as practize d on the Peruvian and Bolivian altiplano is not applied in the study area. In the atmospherically driest lowermost paramos wheat is grown. According to Notestein & King (1930) wheat grows up to 3700 m, and potatoes and onions up to 4200 m. The cycle in shifting cultivation seems to take about 6-7 years in the lower paramo, and is dependant on the recourses of the peasant . After burning and ploughing the original paramo vegetation, potatoes are planted. After the harvest, the soil is left fallow; regeneration to paramo vegetation starts with Rumex acetqeella L., later followed by other species. In the following years the numb'er of species increases. After a few years Hypericum 路 juniperinum shrub replaces the initial Rumex acetosella in some places. In the final stage, the number of species slowly decreases when the area is invaded by Espeletiinae and bunchgrasses. Cattle, horses, donkeys and sheep were introduced by the Spaniards. Camellidae (Lama, Vicuna) thriving in the puna of Peru and Bolivia are absent in the study , area. Sheep are locally ~ommon in dry paramos up to 4500 m whereas cattle, horses and mules may be found moving freely in many paramos. Most of the plant cover in the wetter and steeper places is undisturbed, as in the whole superparamo. In the dry season the paramo vegetation may be set afire to stimulate regrowth of tussocks and bamboos, which are preferred by cattle. Burning caused by lightning is a rare event and has never been observed during the field survey.

32 Recuperation of the vegetation after fire takes years, as was demonstrated by Janzen (1973) for subparamo bush and .bamboos in Costa Rica. Growth of Espeletia grandiflora was determined by Sturm (1978) at 3,5-3,9 em/year. Tussocks, rosette plants and bamboos are well adapted to damage by occasional fire. Further data on the effect of fire on paramo vegetation are scarce. Most research on the impact of fire on neotropical grasslands was carried out in savannas (e.g. San Jose & Medina 1975) . Growth of paramo plants is marked by low speed. Primary production in paramo vegetation is low, as is the case in all high mountains in the world. Cardozo & Schnetter (1976) estimated production equal or higher than in temperate areas, but their study concerned the lower part of the paramo belt . Decomposition is also slow due to low temperatures, a humid climate and absence of larger decomposer insects as ants , termites and wood-boring beetles . As a result of repeate d burning and overgrazing, tussocks and bamboos disappear, leaving a low herbaceous mat , with short grasses (A grostis trichodes A. spp., Paspalum bonplandianum), rosaceous species (Lachemilla spp ., Aca&na spp.) and . other low herbs (Eryngium humileJ E. humbo ldtiiJ Bidens triplin~rviaJ Hypochoeris sessiZifloraJ Siegesbeckia orientaZisJ Jaegeria hirtaJ etc.). Alien species may be found also , simply as a result of the intense and diverse impac路t on the land . Frequent species are HoZcus lanatus L.J Digitalis purpurea L.J

Rumex acetosella L.J Juncus effusus L.J Anthoxanthum odoratum L. J Gnaphalium purpureum L.J Rumex obtusifolius L.J Achillea millefolium L. J Ulex europaeus L.J etc. (Over-)grazing, manuring, trampling and burning due to extensive , and locally intensive farming is most common in the lowermost (bunchgrass) paramos. This mismanagement of the paramo vegetation has its effect on the water supply of lower areas. The paramo belt is indispensable for the water supply (drinkwater, irrigation) of the lower areas (Guhl 1968), especially the .bamboo paramo. Schnetter et al. (1976) demonstrated tha~ the watercapacity of (azonal) Diplostephium revolutum shrub is at least 12x more than in a Calamagrostis ~ffusa颅 Spiranthes vaginata community . In the Cordillera Oriental for instance, the subandean and andean forest belt has the densest popul a tion, which depends on fresh water from the paramo belt . In combination with some agricultural activities, obtaining and storing drinkwater is the most important use of the paramo belt. The conservation of the natural paramo vegetation and an optimal management is the first condition for maintaining reliable water resources . As native fish species are almost absent in the paramo belt trouts (Salmon gairdner ii) have been introduced in many places . They have moved to other paramo lakes and streams and multiply rapidly. They provide an excellent source of protein rich food for the paramo peasants . Superparamo lakes and lakes surrounded by deep bamboo-Sphagnum bogs apparently are not or less suitable for trouts. Mining is fortunately restricted, e.g. limestone in the Paramo de Palacio for cement . It is recommended that areas of high biological and environmental importance (e.g . Sierra Nevada del Cocuy and the calcareous peaks of the Nevada de Sumapaz, Almorzadero , Farallones de Medina, Tama) should be spared as much as possible and that INDERENA (the Colombian National Institute for the development of the renewal of natural resources and envinronment) will continue to develop an active policy for establishing National Parks . General data on the ecology in the paramo and puna were provided by Barclay (1962), Murra (1979) and Flores-Ochoa (1979); by Wagner (1979) for the Venezuelan Merida paramos . Ellenberg (1979) provided an interesting outline of man-made ecosystem succession and land use in the Ecuadorian and Peruvian Andes.

33 Evolution and Quaternary history of paramo climate and vegetation The evolution of flora and vegetation of the high Tropical Andean paramo ecosystems has recently been reviewed by Vander Hammen & Cleef (in press), on the basis of information obtained in the Colombian Cordillera Oriental , a key area for the paramos in the northern Andes. A general outline of that study will be presented here. In addition, some new pollendiagrarns (to be published in the near futur e ), covering the Late Glacial and Holocene history of the Paramo de Sumapaz, will be briefly discussed. This large high paramo extends to about 150 km S of Bogota and was previously not included in palynological studies by Van der Hammen and coworkers . The very origin of the paramo flor a and vegetation lays in the Tertiary, when a non-forest vegetation covered hilly, tropical lowland and low mountains with some kind of upland s~vanna . Savannas are very old, the upland savannas must have been present at least in non-zonal habitats on the Venezuelan Tepuis, at that time possibly the only high mountains in northe rn S. Ameri ca. In lower areas these upland savannas mainly contained local tropi cal elements, especially those which still are common in open savanna and savanna bush. The Tepuian and Amazonian savannas , at present with a limited distribution depending on the presence of special edaphic conditions, stand out by a number of endemic plant taxa. This indicates their long existence unde r repeated or permanent isolation by neotropical forests (Steyermark 1966 , Huber 1978, Schultes 1944 , Van der Hammen 1974) . r hytogeographic analysis of the mode rn paramo flora show that the Tepuis _hardly contributed to its present composition. The Tertiary tropandean hills and low mountains thus were gradually covered by local savanna and forest species from the surrounding lowlands. It is supposed that open vegetation persisted locally on the rising Andean mountains. Such patches on hilltops or ridges are determine d by edaphic factors, whereas z'onal open vegetation may be caused by local arid climate. Ev en today natural (half-) open vegetation is found under such special conditi'ons in the Andean forest belt. This is confirmed by a number of vascular paramo taxa of the (neo)tropical el,e ment growing in lowland savannas. Tropical plants in these uplifted "preparamo" habitats became adapted to lower temperatures, and forest species to open environment. This is suggested by the pollendiagram Tequendama (probably Lower Pliocene) from the Tilata formation on the present high plain of Bogota (Vander Hammen, et al . 1973). Essential for adaptation of plantspecies to lower temperatures is the crossing over the lower nightfrost line , today reaching down to about 2200-2300 m. The "proto- paramo" developed somewhere above the nightfrost line since the Middle Pliocene and contained Composit ae and Gramineae. Among the oldest elements in the proto-paramo are Valeriana, Plantago, Myriophyllum, Polylepis, Aragoa, Ericaceae, Symplocos, Myrica, Miaonia, Ilex, cf. Hydroaotyle, Jamesonia, Hymenophyllum and Hypericum. Also re co rded we re: Myrica , Polygonum, Borreria and Jussiaea (Ludwigia), taxa which at present only just reach the lowermost limit of the paramo belt. Their presence indicates higher annual mean temperatures in the lower parts of the proto-paramo . Valeriana , Ranunculaceae, Myrica are northern immigrants; Hydrocotyle, Myr iophyllum and Plantago entered from the adj acent southern Andean mountains. The etheL taxa large ly originated in local tropical or gondwani c areas. During the Early Pleist路o cette, between about 3 .5 and 1 million years ago, new taxa became add~d, e . g. Caryophyllaceae , Geranium, Lycopodium, Isoetes, and Sphagnum, later followed by Gentianella (G. corymbo sa typ e), Lysipomia, and Acaulimalva, nearly all of a llochtonous origin . Meanwhile, the for es t line moved to a higher position, thus enclosing a paramo belt with a vascular flora that begins to resemble the present one in composition . As from the Middle and Upper Pleistocene some 15 to 20 major glacial/interglacial cycles - palynologi cally determined - must have had a strong influence on the evolution and spec iation of

34 flora and fauna. Depending on the climate the Pleistocenic upper forest line moved from low (10% of the time) and intermediate (40%) positions up to the same or locally higher (50%) level than at present. Moderate temperatures and high humidity alternated with low temperatures and low humidities, and due to the upward moving upper forestline and snowline the former paramo ecoshstems never seem to have reached complete stab{li t y (Vander Hamm~n 1979 ). The Cocuy island (including for half of the total time mentioned the Almorzadero, S. Urban and Romeral paramos) has never been in direct contact with the southern Sumapaz island. Distribution and speciation patterns of modern paramo plants r eflect this separation, and speciation in isolation continues here up till now (Vander Hammen & Cleef, in press). More information is available on the history of Last- and Late Glacial times (Van der Hammen & Gonzalez 1960, Van Geel & Van der Hammen 1973 , SchreveBrinkman 1978, Vander Hammen 1979). Between 44,000 and 2 1,000 B.P., during the maximum extension of the Cocuy glaciers, Polylepis quadr ijuga forests were abundantly present near Lake Fuquene (2650 m). This humid period was followed by a dry and colder bunchgrass paramo phase, which lasted up to 14,000 B.P. The Ditr i cho- Isoetion in the Last 'Glacial Lake Fuquene was replaced in the Holocene by Potametea communities. In the cold and arid last phase o.f the Upper PleniGlacial, the drying-out lake must have been bordered by high 路sedge communities belonging to the Galio- Gratiolion . In the same interval Cyperaceae were also present on the Laguna Ciega (3500 m) on the W slope of the Sierra Nevada del Cocuy (Vander Hammen et al. 1981). The Late Glacial climate became warmer and wetter, and was interruped by the Ciega and the El Abra stadials. During the Andean pollenzones V and VI, corresponding to the European Boreal and Atlantic (7500-5000 BP), the paramos of the study area were smaller than today as a result of slightly higher forest line. The climate became colder again in the Andean pollenzone VIII (corresponding to the European Subatlantic), the humidity increased and the paramo-forest iine moved to its present position. This movement was only interrupted by .the Neoglacial period in recent time, which may have caused local changes of the vegetation. Pollendiagrams reflecting Late Glacial and Holocene conditions in the study area were published for the Paramo de Palacio (Van der Hammen & Gonzalez, 1960b), the Paramo de Guantiva (Van der Hammen 1962 , Vander Hammen & Gonza lez 1965) and the Sierra Nevada del Cocuy (Gonzalez et al. 1965, Vander Hammen et al. 1981). During the present survey in .the Paramo de Sumapaz a number of sections were sampled in tr~nsect 8 (Fig. 2) running E-W across the Nevado de Sumapaz; El Triangulo (4100 m), the Laguna La Guitarra (3425 m), the Laguna La Primavera (3550 m), the watershed at Cuchilla La Rabona (4000 m), Andabobos (3750 m) and the Laguna Gobernador (3800 m). Mr. L. Carvajal (Bogota) and Mr. S. Villalba (Lagunitas, Sumapaz) assisted with the sampling in the Paramo de Sumapaz. Pollen analyses were carried out by Mr. G. Nol dus (La Erimavera, El Triangulo, La Rabona), Mr. J. Martinez-Rea (Andabobos), Mrs. A. Meier & 路Mr. M. Lebouille (La Guitarra) and Mr. G.B.A. van Reenen (Gobernador) .. Mr. H. Hooghiemstra rendered assistence in pollen identification. Publication of the Sumapaz pollendiagrams is planned for the near future. Evidence of the Late Glacial is present in the lake sections of Andabobos and Gobernador. During the El Abra stadial (11,000-10,000/9500 B.P.) both lakes were located in open grass paramo just as today. As from the time of Andean pollenzone V (corresponding to the European Boreal) Compositae and Hypericum subp~ramo thickets extended upslope while the upper forest line continued to move upward. The Andean pollenzone VIa (corresponding to the European early Atlanticum) was warmer than at present, but there is no evidence that both lakes on the W slope and the Laguna La Primavera on the E slope were ever reached by the upward moving humid Andean forest, principally made up of Weinmannia, Alchornea, Melastomataceae and palms, probably Cer oxylon. An apparently co lder in:terval is dated at 6290 (.:!:_ 70) B.P. (GrN-9333- Col 274), and was named the Sitiales phase

35 (Fig. 7). Later, this was followed by a general amelioration of the climate and an increase of the subparamo shrub and/or dwarfforests with Hypericum (probably H. laricifolium, Compositae (probably Gynoxys, Ageratina, Diplostephium, Senecio) and Ericaceae (probably Gaultheria ramo sissima, Vaccinium floribundum) enclosing the hi l ls bordering these lakes. The early part of a cold phase is dated at 4700 (+ ISO) BP (GrN-9331 - Col 272) in the Laguna La Primavera, a date very near to the Europ e an Atlantic-Subboreal boundary. As from that time the paramo climate became colder and the possible combination with an increased humidity caused the open paramo to replace the forest l ine shrubs. Plantago rigida cushion bogs began to develop in the highest parts (Cuchilla La Rabona; 5090 ~ 25 BP. (GrN 8457 - Col 266)) and Sphagnum bogs in the lower part of the paramo belt. There is ample evidence now that the development of most paramo bogs started about 5,000 years ago. Some Hypericum and composite shrub was in the vicinity of the Laguna La Primavera. From the base of zone VIII corresponding to the European Subatlantic onwards, dated at 2920 (+ 130) BP (GrN- 9332 - Col 273) the climate became definitely colder and wetter in de Laguna La Primavera area and approached present conditions. Open zonal grass paramo probably containing bamboos (Swallenochl oa ), largely determined the aspect up to recent time. In the lake La Primavera the Di tricho-Isoetion developed again (Isoetes andicola, I. karstenii , I . palmeri, I. glaciaZis are found at present). The stability of the vegetation, especially in the high paramos, was again affected by the Neoglacial, the Little Ice Age; c. 1500-1800 A. D. Superparamo moraines of the Corralitos stade mark the Neoglacial ice extension in the Sierra Nev~da del Cocuy. Such moraines have not been observed on the steep slopes of the Nevado de Sumapaz (c. 4250 m). Palynological indications, however, of the nearby melting ice are found in the po l lendiagram El Triangulo, bas e d on the analysis of submerged lake sediments under the Isoetetum karstenii (rel. 271). The lower part of the diagram apparently represents upper superparamo conditions with Caryophyllaceae and species of Draba. After a Hedyosmum pioneer phase, the upper Andean forest rapidly returned to its present location and composition . The site is simultaneously reached by composite shrub of the lower superparamo line (Senecio vernicosus, Loricaria complanata). Plantago rigida, Gentiana sedifolia and ijypericum lancioides indicate the establishment of the perhumid upper condensation belt on this peak.

36 MATERIAL AND METHODS

General concepts For the main goal of the present study - to present an inventory description of the modern vegetation of the paramos of the Colombian Cordillera oriental - the Zurich-Montpellier method of phytosociology has been applied, however, with some slight adaptations that will be discussed later . Vegetation study according to the Zurich-Montpellier method includes sampling of representative homogeneous (in composition and structure) stands of a certain minimum size for similar and different vegetation types . The plots are usually selected on physiognomic and floristic criteria throughout the study area . Sampling was carried out at different elevations and in different cross-sections of the paramo belt of the study area . The large number of re[ eves reduces the subjective element in the synthetic procedure. Heterogeneous pl ots were avoided (see Werger 1973) . For the pres ent study a releve included : I) making an inventory of all plant species, except inconspicuous terrestric algae , microlichens and fungi , and 2) estimating the percentage of (canopy) cover for each species . The releves are presented in tables in the usual phytosociological way, which allows the recognition of vegetation units . The units or vegetation types are ranked in a hierarchic system , based on floristic criteria . Only in cases where the vegetation was exceptionally poor in species , additional ecological criteria have been used . Th e Zuri c h-~fontpellier method was used ,, because reliable results have been obtained using this method in other parts of the world . In the tr opic s , this method has mainly been applied to open or semi-open tropical vegetation (e . g . Duvigneaud 1949 , Van Donselaar 1965, Werger 1973 , Van Zinderen Bakker & Werger 1974, Ruthsatz 1977). Whether the Zurich-Jlontp e llier method can be applied to open or semi-open tropical vegetation is no longer relevant . Remains the discussion whether this approach is suitable for zonal tropical forests with their complex structure and their abundance of species (Van Donselaar 1965) . Few examples of the classification of zonal tropical forests are available (Schnell 1952, Mullenders 1954; Schmitz 1962 , 1971 ; Sprangers & Bulasubramanian 1978 ; VanderWerff 1978) . The present author agrees with Werger (1977) , that a reliable fl oristic clas s ification of zonal tropical primary forests a ccording to the Zurich}fontpellier principles is well possible . This is based on the results of the firs.t preliminary tables for the ECOANDES transect studies in zonal forests along slopes in the Colombian Andes (Vander Hammen & Jaramillo , in prep .; Rangel et al. , in prep . ; Cleef , unpubl . ) . Technical descriptions of the Zurich-Montpellier approach of phytosociology were provided by Braun-Blanquet (1964) , Mueller-Dombois & Ellenberg (1974) , Werger (1973, 1974) and Westhoff & Vander Maarel (1973) .

Although many azonal paramo commun~t~es are dominated by one species , their definition is entirely determined according to the Zurich-Montpellier approach . In Europe simply structured communities are often studied according to the methods of the Scandinavian (Uppsala) School . In this study these methods have not been considered , however , since throughout the, Zurich-Montpellier approach was found to give satisfactory r esults as regards the classification of the communities. Field methods and materials Thorough knowledge of the flora is indispensable for any botanical

37 environmental study , especially for vegetation studies according to floristic principles . In absence of flora works for the study area collection of every unknown species in releves is the only way to solve the identification problems of inventoried taxa . After a short training in the taxonomy of Colombian bryophytes in Utrecht by the late Dr . P . A. Florsch~tz and Dr . S. R. Gradstein , Dr . R. Jaramillo M. introduced the author in the vascular paramo flora near Bogota in November <;J.nd December 1971 . Addi t.iortal pertinent ,information was further provided by staff members of the Institute de Ciencias Naturales headed by Dr . A. Fernandez - Perez at that time . Releves (records or sample plots) of the paramo vegetation were gathered in a number of E-W running cross-sections or transects through the study area (Fig . 2). These transects are located in (from N to S) : 1) Paramo de l Almorzadero 2) Sierra Nevada del Cocuy 3) Paramo de Guantiva (southern part) ~Paramo de Pisva - Chita 4) Paramo de la Rusia - Paramos de Tota - Vado Hondo/Pen a de Arnical 5) Paramos NW of Neusa - Paramo de Palac i o - Guasca - Chuza . 6) Paramo de Cruz Verde 7) Paramo de Chisaca 8) Paramo de Sumapaz : S. Juan - la Rabona - Nevada de Sumapaz. It was attempted to cover both the humid and the dry sides of the Cordillera . Usually vegetation studies were conducted near the upper forestline , at middle elevations in the grassparamo and in the reaches of the highest (snowcapped) peaks . Some of the selected cross sections (e . g . 3 , 4 , 5) continue downslope with transects (no. 13 , 14 , 15 in Grabandt 1980) of previous studies of the Andean forests on slopes and foothills conducted in 1967 by Prof . Dr . Th . van der Hammen and Dr . R. Jaramillo Mejia (in prep . ) . Mrs . R. A. J . Grabandt (in prep . ) presently studies the relationship between recent pollenrain and paramo vegetation in the eight selected paramo transects . For general transport a Nissan jeep (4 wheel drive) was used as far as conditions allowed . Further transport to the s e lected campsites was on horseback or just by walking . Camp equipment , plan:t collections and .o ther sampled materials were transported by mules . Usually the jeep driver and a local guid accompanied the expedition . Only two small sleeping tents (type Capriola , Slee BV , Utrecht) were used and a small shelter for storing food and kitchen tools . Elevation was determined by aneroid reading of a Thommen (0-5000/6000 m) altimeter . Altitudes were regularly checked at the Institute Geografico "Agustin Codazzi" (2560 m) , Bogota and also by other points of known altitude according to official topographic maps . The mean daily variation .of elevation according to the altimeter for a given site in the paramo belt amounts to about 35 m (exceptionally up to 50 m) and was occasionally also recorded by a barograph . The compass (Bezard model UBK/3 , Lufft G.m. b . H., Stuttgart) used inc }~ded a clinometer . The topographic base maps (1:25 . 000 and 1: 100.000) were ob t ained from the Institute Geografico "Agustin Codazzi" . Aerial photographs of the selected expedition areas were studied before leaving, especially from ar eas not yet covered by maps . Botanical collections were preserved during the evening and stored in plant presses (vascular specie s) or in aluminium boxes . The drying process was later performed in the Instituto de Ciencias Naturales in Bogota . 路 About 600 releves of paramo vegetation were gathered in the study area during 1971-73 and later during short visits in 1977 and 1978 . The original reference numbers of t he releves are used . Nearly all plot areas 1-424 were almost completely inventoried , making botanical collections of nearly all unknown species (reference number Cleef et al . 1-10 . 430) . Vouchers are deposited in COL (completely} and U. In most cases specimens were also deposited in local herbaria by residing specialists , which are summed up later . The sample plots were layed out in open paramo vegetation of different

38 physiography and included open zonal and azonal habitats as defined by Walter (1954) and Mueller-Dombois & Ellenberg (1974) . The term zonal vegetation is interpreted here in its widest sense and comprises mesic to xeric habitats on level and sloping ground at the base or on tops of slopes . Minimal area and plot size were tested out during 1971 in some communities of the zonal and azonal paramo vegetation near Bogota . In general the plot size used in the present study was strongly dependent on the structure of the vegetation and agrees roughly with values summarized in Westhoff & Vander Maarel (1973 , table I) and Vareschi (1989) . All plots selected were square or rectangular in shape. When all plant species present in the sample plot were recorded , part of them with their reference number, the canopy cover in % was estimated for each species by taking its global circumference as limit . As a rule lower values generally result of estimating the real cover of each plant species . But this is an almost impossible, time consuming task , which is hardly worthwhile, especially when the phytosociological survey covers a large area in a semi-detailed way as in the case of the present study area, which ranges over 10,000 km2 . In . dense spherical shaped, lepto- or nanophyllous sl:trub or in densebunchgrassland differences between canopy cover and real cover are hardly existing . In rare hypericaceous shrub (e.g . Hypericum lancioides , H. trianae, etc.) or isoetid vegetation (e . g. Isoetetum karstenii typicum) real cover may be about half of the canopy cover. In general terms estimates of canopy cover obviously are usually somewhat higher than real cover . The discrepancy between these two parameters is strongly determined by species- bound characteristics like leaf-form and -size, leaf-packing and canopy arrangement . On the other hand environmental variables , which are site-determined, also have their impact on this , so that the ratio between canopy and real cover may differ between the populations of one species growing on different sites . Cover iwas estimated for all species together forming vegetation layer i . e . the total cover estimated for the releve may in that case amount to more than 1,00% . Obviously the total canopy cover in one stratum however was never more ~han 100%, even though species may have interlocking canopies . This holds for each layer . Mainly because of further mathematic elaboration of data for e . g . studies on recent pollendeposition and its relation with fossil evidence, the canopy cover of each of the"modern"species was estimated in % as accurate as possible . Between about\ 20 and 80% however, cover was estimated in intervals of 5% (e . g . 20- 25- 30 - 路 (33 1/3)- 35- 40- 45 etc . ), since it is extremely diff~cult to establish more exact values in this traject . Cover of less than 1% was listed as " 1". For the sake of comparison it seems an advantage that all records were made by the same investigator. Abund.imce was estimated only when cover was less than 5% , and usually less than 1% . Presence of numerous specimens of a given species is indicated by adding a "+" to the cover %. Sociability was not recorded. Cover values recorded in this way may be easily translated in any phytosociological scale and further worked up in quantitative studies . Airborn pollen was gathered in about 400 releves by collecting some 10-15 random samples of the bryophyte layer (or upper soil layer in lake and ponds) . These are currently under study (Grabandt, in prep . ). A number of additional observations was made in each sample plot . Recorded were cover (in %) and height (in cm/m) of main constituing"growth forms": e . g. shrub, herbs , grasses , bamboos, stemrosettes , bryophytes, lichens and algae. Further the approximate size of the who~e phytocoenosis sampled was estimated and if 路 time allowed a line transect of this and adjacent vegetation was surveyed and depicted . Such drawings contribute to knowledge about borders in vegetation and visualize structure and (in part) texture characters of the vegetation type(s) under study . The actual phreatic level, the presence or temporarily absence of lateral water supply or depth of the standing waterbody were recorded. Soil depth , texture and thickness of the various layers were determined with an 1. 20 m auger. Soil colors

39 were noted according to the "Revised Standard Color Charts" (Japan) . pH was measured ; if not otherwise indicated, pH values always refer to the upper , mostly humic soil layer at about 10 em depth. They were measured by Mieke Cleef-van Rens using an electrometric equipment Metrohm. pH records of water are marked are marked an asterisk*) . About 1-20 cc soil sample was left in suspension in distilled water , up to 50 cc, during approximately 24 hours and measured after stirring . The suspensions were measured after 48 , 72 and 96 hours . Samples mostly showed a slight decrease of acidity with time . The measurements , also applied in soil samples from the Buritaca transect in the Sierra Nevada de S. Marta , seem to be reliable as they agree well with measurements according to international standards by the Laboratory of Physical Geography and Soil Science of the University of Amsterdam carried out 1-2 months later . Only occasionally pH values were determined along the whole soil profile . A sample of the upper soil layer (0-20 em) of each releve is in store and will be used for determination of grain size, organic content and probably some of the bio-elements . These data will contribute to a characterization of the pedological properties of the different paramo plant communities . Further field data taken concern locality , altitude , physiography , inclination , size of the releve area , exposition , shadow , drainage , phreatic level , macroscopic (soil) fauna, influence of fauna, fire and man . Mostly also a photo or colorside was taken from the releves . Vareschi (1980) determined the minimal area for some zonal and azonal phytocoenoses inhabited by Espletiinae in the Venezuelan 路 Andes . Minimal areas applied by me in paramo grassland (25-35 m2) and in tall shrub (up to 50 m2) of the study area, agree well with those of Vareschi . A few zonal and azonal shrub and dwarfforest stands are only briefly treated here , because they will be described elsewhere in more detail . Omitted were all epiphytic and epilithic communities , as well as the plantcover of deep paramo lake bottoms . A number of plants collected in these habitats , however , may give a first glance on the floristic composition of these communities . Laboratory methods and synthesis First of all the rich botanical collections exceeding more than 10.000 numbers had to be named. A good number of vascular plants was yet identified by colleagues and the author in the Herbaria Nacional Colombiana (COL) at the Institute de Ciencias Naturales of the Universidad Nacional in Bogota , which was our base in 路Colombia . Back at the Utrecht Institute of Systematic Botany numberous unidentified collections were forwarded to specialists in various countries , because floras do not exist for the study area . Determination activities took some years and are still not yet completed . With regard to liverworts and lichens all support towards their identification was given by respectively Dr . S.R . Gradstein and Mr . H.J.M . Sipman. Dr . D. Griffin, III (Gainesville) supported by a visitor's grant of WOTRO, took over general l . . .' .. d ~t ermlnatlons of the mosses from the late Dr . P . A. F1orschutz . All colleagues and friends, which gave a consistent support towards identification of the paramo plant collections are alphabetically listed below . Their help is most gratefully acknowledged here . Some 100 new taxa were found; most of them have been published by now . Ando , H. HIRO (Hiroshima , Japan) Hypnum, Pleurozium Balslev, H. NY/AAU (New York , USA/ Aarhus, Denmark) Juncaceae Bell , B. G. ACHE (Penicuik , Great Brittain) Grimmia Bicudo , R.M. T. SP (Sao Paulo, Brazil) Nitella Buck , W. R. NY (New York , USA) Polytrichaceae Berberis Camargo , 0 L . COL (Bogota, Colombia) US (Washington, USA) Compo sitae Cuatrecasas , J .

Campbell, E.O. Diaz-Piedrahita, S. Dunn, D.B. Fernandez-Perez, A. Florschiitz, P.A. Frahm, J. - P. Fuchs-Eckert, H.P. Fulford, M. Gorts-van Rijn, A.R.A. Gradstein, S.R.

MPN (Palmerston North, New Zealand) COL (Bogota, Colombia) UMO (Colombia, USA) COL (Bogota, Colombia) U (Utrecht, Netherlands) Frahm (Duisburg, Federal Republic of Germany) - (Trin-Vitg, Switzerland) CINC (Cincinnati, USA) U (Utrecht, Netherlands) U (Utrecht, Netherlands)

Griffin III, D.

FLAS (Gainesville, USA)

Grolle, R.

JE (Jena, German Democratic Republic) U (Utrecht, Netherlands) U (Utrecht, Netherlands) US (Washington D.C., USA) K (Kew, Great Britain) U (Utrecht, Netherlands) CMI (Kew, Great Britain) U (Utrecht, Netherlands) AAU (Aarhus, Denmark) TNS (Tokyo, Japan) COL (Bogota, Colombia)

Gronde, K. van der Haarbrink, J. Hale, M.E. Harley, R.M. 't Hart, H. Hawksworth, D. Hofstede, J.W. Holm- Nielsen, L.B. Inoue, H. Jaramillo Mejia, R. Jeppesen, S. Jermy, A.C. & J.A. Crabbe

AAU (Aarhus, Denmark)

Lellinger, D. Loon, J.C. van Lourteig, A.

BM (London, Great Britain) P (Paris, France) LD (Lund, Sweden) U (Utrecht, Netherlands) U (Utrecht, Netherlands) UB (Brasilia, Brazil) NY (New York, USA) H (Helsinki, Finland) zss (Zurich, Switzerland) CTES (Corrientes, Argentina) (Fukuoka, Japan) LEA (Lethbridge, Canada) WAG (Wageningen, Netherlands) US (Washington, USA) U (Utrecht, Netherlands) P (Paris, France)

Lowy, B. Maas, P.J.M.

- (Bouton Rouge, USA) U (Utrecht, Netherlands)

Jovet-Ast, S. Karnefelt, J. Kastelein, W.J. Kieft, E.G.B. Kirkbride Jr., J.H. Koyama, T. Koponen, T. & A. Kramer, K.U. Krapovickas, A. Kuwahara, Y. Kuyt, J. Leeuwenberg, A.J.M.

Marchantia Compositae

Lupinus Orchidaceae, Lentibulariaceae general identification of mosses

CampyZopus, Chorisodontiwn, PiZopogon Isoetes Leptoscyphus Peperomia, PoZygaZa general identification of liverworts general identification of mosses, esp. Prionodon, Sphagnwn, Bartramiaceae, watermosses

TyZimanthus, CheiZoZejeunea Neesioscyphus Jensenia, Symphyogyna FruZZania subg. ChonantheZia

Parmeliaceae Labiatae

TiUaea AZectoria Parietaria Potamogeton, LiZaea PZagiochiZa, SyzygieZZa general identification of Compositae,

Centropogon, Lobelia Isoetes Co lura Cetraria Drymaria LachemiZZa Rubiaceae Cyperaceae

PZagiomniwn, Splachnaceae Polypodiaceae

AcauZimaZva (in study} Metzgeria Loranthaceae

Desfontainea SeZagineZZa Geraniwn RanuncuZus, OxaZis LimoseZZa; Montia (in study) Auricularia, TremeZZa Burmannia, TofieZdia, Orthrosanthus

Mathias, M.E. & L. E. Constance Meenks, J. Mi ckel, J.T . & L. Atehortii.a Molau, U. Moldenke, R. N. Mora Oseja, L.E. Moschl, w. Murillo, M.T . Ochi, H. Â˘llgaard, B. Pinto Escobar , P. P6cs, T. Ponce de Leon , P.P. Pringle, J . Punt, W. Rahn, K. Raven, P . Ravenna, P. Read, R.H. Reenen, G.B . A. van Robinson, H. Robson, N.K. B. Romero-C., R. Simpson, B. B. Sipman, H. J . M.

UC (Berkeley, USA) U (Utrecht, Netherlands

Umbelliferae

NY (New York, USA) GB (Goteborg , Sweden) FMH (Plainfield, USA) COL (Bogota, Colombia) GZU (Graz, Austria) COL (Bogota, Colombia) Ochi(Tottori , Japan) AAU (Aarhus, Denmark) COL (Bogota, Colombia) EGR (Vacrat6t, Hungary) F (Chicago, USA) HAM (Hamilton, Canada) U (Utrecht , Netherlands) C (Copenhagen, Denmark) MO (Saint Louis, USA) SGO (Santiago, Chile) WIS (Madison , USA) U (Utrecht, Ne therlands) US (Washington DC, USA) BM (London, Great Britain) COL (Bogota, Colombia) TEX (Austin, USA) U (Utrecht, Netherlands)

Elaphoglosswn Calceolaria Lantana, Eriocaulaceae Lilaea, Cype raceae, Haloragaceae Cer astiwn Polypodi aceae, Equisetwn

Slageren, M. van Sleumer, H. Smith, L.B.

U (Utrecht, Netherlands) L (Leiden, Netherlands) US (Washington DC, USA)

Brachiolejeunea Escallonia, Clethra, Ericaceae Xyris, Begonia, Bromeli aceae (esp. Puya)

Soders trom , T.R. Takaki, N. Taylor, P. Tryon, A.F. Turner, B.L . Uribe U., L. Vana, J.

US (Washington DC, USA) Hb. Takaki (Nagoya , Japan) K (Kew, Great Britain) GH (Cambridge, USA) TEX (Austin, USA) COL (Bogota, Colombia) PRC (Praha, Czechoslovakia)

Vitikainen, 0. Wasshausen, D.C. Web'e r, W.A. Westra , L.Y. Wurdack, J. Zander , R.H.

H (Helsinki, Finland) US (Washington DC, USA) COLO (Boulder, USA) U (Utrecht, Netherlands) US (Washington, DC , USA) BUF (Buffalo, USA)

Riccardia

Bryoideae

Lycopodiwn Gramineae

Lepidozia Lycoperdon Gentiana, Halenia (in study) Euphorbiaceae

Plantago Onagraceae

Sisyrinchiwn Elagine Her bertus Eup a torioideae

Hypericwn Aragoa Polylepis general identification of lichens , esp. Cladonia, Parmeliaceae

Gramineae

Aongstroemia Utricularia Jamesonia Aphanactus Melastomataceae

Anastrophyllwn, Marsupella, Cephalozia, Gymnomitrion, Jungermannia Peltigera Acanthaceae

Carex peucophila Orchidaceae Melastomataceae, Mannina Pottiaceae

In an early stage a first attempt was made to divide all (about 600) releves in groups which share similarities in phy siognomy, floristics and eco l ogy. The releve data were worked up as outlined fn some technical descriptions of the Zurich-Montpel li er approach of vegetation science c ited before. Almost all available releves were included, only few were left out for reasons of obvious heterogeneity. The syntaxonomi cal part of the present study is based upon about 270 releves of mainly azonal vegetation. The other releves, which are grouped in as yet unfinished tables of the vegetation, serve for the description of the

zonal "communities" of the paramo vegetation. Formal syntaxonomical accounts and tables will be published in the future. In the hier archic system provided here for most of the azonal paramo vegetation the association differs from other associations by the prP.sence of (proper) character species. Subassociations are mainly characterized by two, but usually more differential specie s. Variants are based on at least one differential sp e cies, which in extreme environmental conditions may attain a high cover. If two or sometimes more .differential species are reported, they may have low presence and low cover. Units of lower rank are not recognized. Characterspecies are provisionally ranked in this study as exclusive, selective or preferential. The provisional status in the present study is applied because I) no definite constancy tables are yet published, and 2) it is unknown in which other phytocoenoses character species occur at other latitudes and/or elevations. Diagnostic taxa include character and differential species or taxa. Also constant companions may have diagnostic significance, e.g. EZatine cf. chiZensis in the EZatino- Juncetum ecuadoriensis (table 9). As a rule most diagnostic taxa are only (locally or) regionally relevant and identified as such on the basis of the few vegetation studies available from other parts of the Andes. Based on these studies also a few alliance, order and class character species could be identified. Especially with regard to azonal aquatic and boggy communities, which are wide tropical Andean in distribution, it was felt as a disadvantage that the high Andes south of Colombia was not surveyed by the author. As . far as possible the azonal paramo ve getation of the Cordillera Oriental is syntaxonomically ranked on the basis of the releves available. Excepted are the Sphagnum bogs, which here are described as different communities on the basis of raw tables of the vegetation. They are omitted for the moment, because of the fact that the transition of azonal Sphagnum bog to zonal bamboo paramo is gradual . Both paramo Sphagnum bogs and zonal ve getation will be syntaxonomically treated in forthcoming studies, which will also include presence/constancy tables. Other azonal vegetation units, which were not finally classified, are also described here as "communities", though part of them undoubtedly belong to higher syntaxa described here. Few records, loc al presence, uncertain (syn-)taxonomical status, or optimal development elsewhere at other elevations or latitudes are some of the different reasons for not classifying them definitely in this paper. It should be emp,hasized that the term "characteristic species" mentioned under "communities ' does not mean the same as "character species". Though, it is believed that most characteristic taxa wil l prove to be diagnostic taxa when the syntaxonomical classification is completed. A synt a xon is given a provisional status ("prov.n) when I) its description is based on a single releve or on 2) uncomplete record(s), or when 3) the identity of (some of) the diagnostic taxa is insufficiently known, or when 4) vegetation studies from other regions of the high tropical Andes might cause a future change in name or delimitation of a given syntaxon (e.g. Gentiano-Oritrophi on prov .; Werner ietea prov.). As r e gards nomenclature, Barkman et al . (1976) has been followed . These authors do not deal with syntaxa under the rank of subassociation. In this study, however, also a nomenclatural type was assigned to the variant level. In the author's opinion this is a logica l consequence of the type method ado.pted by the Nomenclature Commission of the International Society of Veg e tation Science. Nomenclatural types are inaicated in the table by symbols: type of the class type of the order type of the alliance A type of the association type of the subassociation 0 type of the variant o The symbols for the association and subassociation were proposed by Daniels (1980).

* **** *

43 The application of the terms typicum and inops for subassociations and variants follows Westhoff & Vander Maarel (I973) . Apparently no previous syntaxonomical studies on the Colombian paramos were published . The only ones dealing with paramo vegetation are those of Vareschi (I953, I955) from Venezuela. Names of paramo syntaxa recently published by the same author (Vareschi I980) are not valid according to Barkman et al. (I976). Other syntaxonomical studies in tropical high Andean vegetation include those of Ruthsatz (I977) for the NW Argentinan puna and those of Gutte (I980) on Peruvian vascular cushion bogs and high Andean lakes. For various countries most useful chorological and ecological information was ' supplie .d by the following authors: Chile: Roivainen (I954) , Schmitthusen (I956) , Oberdorfer (I960), Ricardi & Marticorena (I966) and Villagran (I980); Argentina: Hunziker (I952), Cabrera (1958), Bacher et al. (I972), Werner (I974) and Ruthsatz (I977); Bolivia: Herzog (I923) and Collot (I980); Peru: Weberbauer (I9II), Raun & Falk (I959), Koepcke (I96I), Tovar Serpa (I973), Mueller & Mueller (I974), Gutte & Gutte (I976) and Gutte (I980); Ecuador: Acosta-So lis (I 958) , Diels (I 937), H路a rling (I 979) and 0llgaard & Balslev (I979); Colombia: Cuatrecasas (I934, I958 and in litt.), Lozano & Schnetter (I976), Aguirre & Rangel (I976), Fosberg (I944), Sturm (I978) and Rangel et al. (I976); Venezuela: Aristeguieto & Ramia (I952), Az6car & Monasterio (I979), Farinas (I979), Monasterio (I979), and Vareschi (I953, I955, I956, I958, I980) ; and Costa Rica: Weber (I958). In addition other useful information was obtained from Beaman (I956) , Beaman & Andresen (I966), and Villapanda (1968) on the Mexican high mountains and from Komarkova (I979) on the high Colorado Rocky Mountains. In the tables relevant ecological information is summarized in the heads of these tables . For s路oil texture the following abbreviations are used: "c" for clay, "s" for sand, "si" for silt, "g" for gravel, "p" for peat and "y" for gyttja. In the descriptions of the communities the word "soil" has been used in a rather wide sense, including proper soils (in the pedological sense), but also the upper layer of the substrate (of the lake sediment or peat) of in lakes, in mires and in bogs, where the plants usually are rooted. According to the literature pH level of aquatic samples (indicated with an asterisk *) is slightly higher as compared with top soil samples. A releve marked with an asterisk (x) means, that the survey generally was based on a quick, not complete inventory, usually without botanical collecting. The total number of species refers to the total number of cormophyte species distinguished up till January I98I, when final tables were constructed. Further data given include : date, locality, pH, collection numbers , soil depth (em) , exposition, slope, e tc . Most of them are summarized in Appendix 3 or appear in the tables . Par~o plant species are usually cited without the authorities and without the corresponding family . Only for the native vascular species of the study area mentioned in this study, they are provided in a list (Append ix 2); whereas for mosses, liverworts and (macro)lichens reference is made to the rec.ent checklis ts (Florschutz-de Waard & Florschutz I979 ; Gradstein & Hekking I979 and Sipman & Hekk ing, in prep . ) and their supplements in preparation. Unknown species are listed with the author's collection number . In the general community and habitat description for slope angle and acidity Daniels (I980) was followed:

44 3.5-4.5 strongly acid pH flat/level 0-2° 4.5-5.5 moderately acid slightly sloping 2°-4° 5.5-6.5 weakly acid sloping 4°-8° 6.5-7.5 neutral 8°-15° moderately steep 15°-30° steep and more very steep 30° Boundaries between different pH levels run about parallel to the subdivision of e.g. Ratcliffe (1964). Thus, the upper pH level in oligotrophic environment is at 5.0 (5.5 in aquatic medium), in mesotrophic environment at 6.0 (6.5 in aquatic medium) and in eutrophic conditions from 6.0 onwards.

slope

II.

ALTITUDINAL ZONATION AND OUTLINE OF THE ZONAL PARAMO VEGETATION

ALTITUDINAL ZONATION~) Altitudinal zones of the north Andean paramo vegetation have been described by Cuatrecasas (1934, 1958, 1968), Fosberg (1944) and Cleef (1978, 1979a) for Colombia; by Vareschi (1970) and Monasterio (1979) for Venefiuela and by Diels (1937), Acosta-Solis (1968), Harling (1979) and Lauer (1979a,) for Ecuador . The altitudinal sequence of the zones of the zonal paramo vegetation on the atmospherically dry and humid sides of the Colombian Cordillera Oriental will be discussed. The subdivision is mainly based on differences in physiognomy and floristics. Whether the subdivision can be generally applied to the north Andean paramos remains to be determined. In the parque Los Nevados in the Colombian Cordillera Central, a proper subparamo zone cannot be distinguished (Cleef et al., in press). Apart from differences in edaphical conditions, the climate is .the determining factor for spatial distribution, physiognomy and floristics (at least of the dominant plants) in the altitudinal zones of the recent paramo belt. Accordingly, the slopes facing dry inter andean-valleys or interjacent high plains are atmospherically dry . Slopes above the Amazonian Hylaea, the Orinoco savannes and the deep Magdalena river valley are atmospherically humid. Distinct differences in composition and structure of the Colombian paramo vegetation undoubtedly reflect different macro-climates. For example, "pajonales" dominated by tussocks or bunchgrasses (mainly Ca Zamagr ostis effusa ) are characteristic for the dry side of the mountains. "Chuscales", open bamboo vegetation types (mainly SwaUenoahZoa spp路.), are predominant on the atmospherically humid slopes. Thus, a b u n c h g r as s p a r am o is found on the atmospherically dry side of the Cordillera and a b a m b o o p a r a m 0 on the atmospherically humid side. On the basis of physiognomical and floristical criteria, Cuatrecasas (1954, 1958, 1968) subdivided the paramo into 3 altitudinal belts: I) the subparamo , 2) the paramo proper ("ryaramo propiamente di cho") and 3) the superparamo . His division proved to be useful and has also been applied here. On the .basis of our results and with the use of similar criteria a lower and an upper zone could be recognized in each altitudinal belt of the zonal paramo vegetation . These zones will be described for each side . of the Cordillera in the' order of increasing altitude (Fig. 8). Atmospherically dry paramo slopes The 1 o w e r s u b p a r a m o or s h r u b p i r a M o near the upper forestline carries bushes of Ericaceae, Compositae and Melastomataceae. Common and characteristic genera are: Be fari a, Cavandishia, Maa Zeanea,

~)An adapted version of this part of the chapter on the altitudinal zones of the paramo vegetation will be published by Vander Hammen & Cleef (in press).

Eupatorium (Ageratina ), Senecio , Baccharis and Diplostephi um, Miconia, Bucquetia ana Brachyotum. Solanum bogotense, Seri co theca argentea, Stevia lucida and Cor i aria r usci f olia ssp. micr ophylla are common in the transitional zone between forest and paramo; just as scattered small trees of Budd leia lindenii , Hesperome les , Gynoxy s, Mannina ana Rapanea dependens . Dense thickets of Myr ica parvifol i a are locally frequent. At higher elevations the vegetation in the u p p e r s u b p a r a m o or d w a r f s h r u b p r a m o is mainly dominated by rubiaceous dwarfshrubs of Arcytophyllum ni t idum , accompanied by Calamagr ostis e ffus a and other plants from the open grass paramo. Gaylus sacia buxifolia , a characteristic ericaeous dwarfshrub, and Chae tolepis microphylla are common. Te rrestric orchids, e.g. the beautiful salmon-pink flowering Spir anthes vagi nata, Altensteinia leucantha, A. f i mbriata, as well as Eupat orium (= Lourtei gia ) microphy llum , Miconia parvifolia, Paepalanthus paramensis and Ve rbes ina baccharidea seem to be restricted to this zone. The last mentioned sp e cies grows in rocky pl a ces ~v ith a thin soil and is associated with small, dense tus s ocks of Sporobolus lasiophyllus .

In the l o w e r zone of the . p a r a m o p r o p e r - the l o w e r b u n c h g r a s s p a r a m o - dwarfshrubs generally disappear and are replaced by tussocks or bunches of Calamagr os tis effusa, which become dominant with increasing altitude . Typical light-requiring plants of the open paramo , which are also present in the upper subparamo, are abundant, e . g . Acaena cylindristachya, Azorella aff . cuatrecasasii, Cas t r atella piloselloides , Lobelia tenera, Luzula cf. r acemos a, Oreobolus obtusangulus ssp. rubrovaginatus and Rhynchospora paramorum. Endemic species of the stemcomposites Espeletia and Espe letiopsis are undoubt e dly the most characteristic components of the grass p a ramo. ~1ore or less closed s t an ds of Calamagr os t is effusa bunches make up the . zonal plant cover in the u p p e r zone of the p a r am o p r o p e r, the so- cplled u p p e r b u n c h g r a s s p a r a m o. Towards the upper part of this zone the grass cover is less and only few tussocks are found at the superparamo border. Conspicuous in this zone are species of the Espeletiinae and Hyper icum selagi noides , Jamesonia bogotensis , Pae palanthus lodi culoides var. flocco sus, Stephaniella paraphyllina (Hepat . ) and lichen species of Diploschistes and Lecidea . Ca lamagr ostis recta tussocks, dominant in the zonal grass paramos of the Cordillera Central, are only known from the highest parts of the Cordillera Oriental; these parts are covered with grass paramo vegetation. On the Cuchilla Puentepiedra, the watershed between ' the Paramo C6ncavo and Alto Valle .d e Laguni llas, on the climatologically dry side of the Sierra !路l ev ada de Cocuy, a continuous (upper) bunchgrass paramo, with e.g . Calamagrostis r ecta and Espeletiinae, was observe d up to at least 4450 m. The special edaphic conditions there are dis cussed by Vander Hammen et al. (1981).

In the superparamo the plant cover is sparse; generally, vegetation is found in patches. Low temperatures are prevailing , and diurnal freezing and thawing cau s es various kinds of tro p ical soiifluction phenomena, described by Troll (1958). Here, the number of plant species is smaller than in paramo vegetation in lower areas, but the percentage of endemics is high, especially in the vascular flora of the Sierra Nevada del Cocuy.(Van der Hammen & Cleef, in press). In th e 1 o w e r s u p e r p a r a m o a narrow belt of the remarkable composite dwarfshrub Loricar ia complanata fringes the upper grass paramo line. Dense composite thickets , mainly consisting of Senecio vaccinioides a ssociated with S . andicola, Diplostephium r homboidale and D. alveolatum, are found locally on young terminal moraines along the grass paramo-superparamo border (4300-4400 m) on the atmospherically drier W slope of the Sierra Nevada

47 del Cocuy . Stems and branches of these interesting bushes are covered with a thick layer of the moss Zygodon pichinchensis, especially in sheltered stands . Lower superparamo vegetation on dry moraines is sparse and consists mainly of vascular plants. A creeping ericaceous dwarfshrub , Pernettya prostrata var. prostrata, is locally dominant. Common species are: Agrostis boyacensis, A. haenkeana, Bartsia sp ., Diplostephiwn colombianum, Draba litamo, Jamesonia goudotii, Lachemilla tanacetifolia, Luzula cf. racemosa, Lycopodium crassum, Orithrophium cocuyense, Senecio guicanensis, Poa spp., Bryum genucaule, Cora pavonia (Lie~), ,Polytrichum iuniperinum (Musci), etc. All the speci e s mentioned are also present on the atmospheri cally humid slopes of the superparamo and most of them locally also in the upper grass paramo. In the uppermost zone, the u p p e r s u p e r p a r a m o, the bioma ss and the number of species are considerably reduced . Only a few scattered, often poorly deve loped species remain, e.g. Agrostis boyacensis, Calamagrostis sp. (S806), Luzula cf. racemosa, Pernettya prostrata var. prostrata, Poa sp.,

Senecio guicanensis~3. cocuyanus, S. supremus, Andreaea rupestris, Bryum argenteum, Ditrichum gracile, Polytrichum juniperinum, Racomitrium crispulum, Stereocaulon vesuvianum var. nodulosum. Th e upper superparamo in the Colombian Cordillera Oriental is restri ct e d to the Sierra Nevada de r Cocuy, where at present .the permanent snowcap is withdra~ to about 4800 m, whereas glaciers reach about to 4400 m. Atmospherically humid paramo slopes Bamboos are an important component of the paramo vegetation on the humid side of the Cordillera, from the for es t line up to the lower boundary of the superparamo. Swallenochloa is the most common genus ; Swallenochloa tesselata is widely distributed in the atmospherically humid paramos of the Cordill era Oriental . Some other bamboo species , e.g. Chusquea scandens, Neurolepis aristata and Aulonemia trianae, belong to the timberline vegetation and locally reach into the subparamo. The climatologically humid side of the Cordillera contains an altitudinal sequence of zonal paramo vegetation, comparable to that on the dry side, but the main difference is the predominance of bamboos in the lower part of the paramo belt . The presence of Swallenochloa might be explained by the high annual precipitation (Gradstein, et al. 1977, Cleef 1978) as well as by the permanent a tmosphe rica l humidity that causes a limited diurnal range of prevailing low temperatures. A prominent formation, mainly consisting of Compositae, is found in the s u b p a r a m o or s h r u b p a r am o. Thicket s of Eupatorium (Ageratina) - tinifolium are conspicuous. In addition to many bryophytes, commonly associated vascular taxa are e.g. Aragoa lycopodioides, Baccharis spp., Centropogon ferrugineus, Diplostephium spp., Escallonia myrtilloides var. myrtilloides, Gaiadendron punctatum, Gaultheria ramosissima, Hypericum spp., Oreopanax spp ., Purpurella grossa, Miconia sect. Cremanium, Rapanea dependens, Symploco s spp., Ternstroemia meridionalis. The bamboo Neurolepis aristata is locally found in large groves. 1 ow e r

In the u p p e r s u b p a r a m o or (b am b o o -) d w a r f s h r u b p a r a m o the aspe c t of the zonal vegetation is determined by a laye r of dwarfshrub and bamboos. Just as on the dry mountain side, Arcytophyllum nitidum is present but with a markedly lesser cover. This species is found on rocky slopes and associated with Swallenochloa and several species of bryophytes, e.g. the mosses Rhacocarpus purpurascens, Campylopus cucullatifolius and the liverworts

JamesonieZZa rubricauZis and Lepidozia sp. Locally present are Sphagnum mageZZanicum, S. sancto- josephense and an unknown species of S. sect. MaZacosphagnum (9910) . In general, various ericaceous dwarfshrubs, SwaZZenochZoa tesseZata, composites and the abundance bryophyte s are typical for this zone. The ericaceous species Disterigma empetrifolium plays an important role in zonal vege tation , and is accompanied by other dwarfshrubs, e . g. Befaria tachirensis, Vaccinium floribundum and Plutarchia spp; further species of Clethra, Ilex , Symplocos and, Ugni myricoides, HypericUm pimeoloides , H. papillosum,

H. sabirliforme, Eupatorium (Ageratina) vacciniaefolium, Diplostephium huertasii, D. spp., Senecio spp., and speci e s of Blechnum subg. Lomaria with r eal trunks . Tiny whitish lilies of Tofieldia falcata, lo cally Spiranthes coccinea (= S . vaginata~ and the rar e monotypic Nephopteris maxonii are characteristic endemic species for the atmosphe rically humid zonal subparamo vegetation and seem to be restricted to this zone. In the 1 o w e r b am b o o p a r a m o, which is almo s t entirely dominated by Swallenochloa tesselata, some scattered dwarfshrubs can be observed. In the driest localities Calamagrostis effusa is present but with a lowe r cover. Small rosettes of CastrateZla piloseZloides (and locally C. r osea) are common in this be lt , but were also observe d in lowe r parts of the dwarfshrub paramo. They are generally associated with Rhynchospora paramorum, Oreobo lus obtusangulus ssp. rubrovaginatus, Oritrophium peruvi anum ssp ., Pinguicula elongata, Xyris acutifolia and the moss Rhacocarpus purpurascens; Lysipomia muscoides ssp. simulans, Sisyrinchium pusiZlum, Paepalanthus pilosus and P. Zodiculoides are commonly present. In the lower belt thes e species a re associated with Arcytophyllum nitidum . Humid, flat or gently sloping areas contain dense Swallenochloa - Sphagnum bogs, with as most common Sphagnum species S. magellanicum, S . oxyphyllum, S. cuspidatum and S. sancto- josephense. These bogs have a particularly rich bryophyte flora , the most important elements of which are the mosses Breutelia chrysea, B. allionii , Campylopus cavifolius, C. cucullatifolius, Chorisodontium speciosum and Leptodontium wallisii ; the liverworts Adelanthus lindenbergianus , Anastrophyllum spp.,

Cephalozia dussii , Herbertus subdentatus, Isotachus multiceps, Kurzia verrucosa, Lepidozia spp. , Lep toscyphus cleefii, Riccardia spp., and Telaranea nematodes (Gradstein et al. 1977); and the lichens Cladonia colombiana, C. furcata and C. polia (Sipman & Cleef 1979). An u p ~ e r b a m b o o - b u n c h g r a s s p a r a m o is different from the previous zone by a hi gher cover of Calamagrostis effusa and a lower one of Swallenochloa. The upper limit of the Swallenochloa dwarfbamboos is at 4100-4200 m (ex tending along streams up to nearly 4250-4300 m) and s eems to be determined by frost damage and drought . Precipitation diminishes with altitude in the highe r paramos. This is confirmed by th e composition of the pl ant cover . Thus, the general vegetation in the upper part of this zone resembles that of the atmospherically dry slopes and is classified as upper bunchgrass paramo. It consists of an open sward of Calamagrostis effusa bunches with species of Espeletia , Cerastium and Anastrophyllum; Jamesonia bogotensis however , is nearly absent. Along the lowe r boundery of the superparamo, a narrow belt of low

Loricaria complanata bushes is found again, especially on stony, shallow but stable soils. As a result of the nearly constant and high atmospherical humudity on this side of the Cordillera Jamesonia goudotii, Lachemilla nivalis, Oritrophium peruvianum ssp . peruvianum and Valeriana plantaginea are intermixed here with the Loricaria bush, and many species of bryophyte s, e.g.

Rhacocarpus purpurascens, Racomitrium crispulum, Campylopus pittieri, Anastrophyllum nigrescens, Gymnomitrion atrofilum, Herbertus subdentatus, Jensenia florschutzii.

49 Conspicuous lichens are Cora pavonia, CZadonia subg. Cenomyce , PeZtigera spp., SiphuZa spp. and Sphaerophorus meZanocarpus. In general, the more humid climate seems to be advantageous to a larger number of plant species (resulting in a less discontinuous vegetatii'>n in areas with more or less permanent fog) in the humid 1 o w e r s u p e r p a r a m o, as compared with that on the opposite dry side of the Cordillera. Senecio niveoaureus is the most conspicuous and characteristic plant in the open zonal communities covering the morainic slopes locally with loamy matrix. Other characteristic plants are Erigeron chionophiZus, E. ecuadoriensis, Senecio spp. , DipZostephium rupestre, VaZeriana pZantaginea, Draba spp. (e.g. section ChamaegongyZe), Mantia meridensis, Ourisia muscosa, HymenophyZZum trichophyZZum, Arenaria venezueZensis and Cerastium spp. Some species of the Espeletiinae penetrate into the lower part of this zone.Typical bryophytes are

BreuteZia integrifoZia, BZindia acuta, ErytrophyZZopsis andina, Kingiobryum paramicoZa, Distichium cappiZZaceum, Zygodon spp. (Musci) and CheiZoZejeunea (subg . StrepsiZejeunea) sp. and AnastrophyZZum austro- americanum (Hepaticae) . AzoreZZa muZtifida, Bartramia augustifoZia, Aongstroemia juZacea, Herbertus subdentatus, PZagiochiZa dependuZa, Rhacocarpus purpurascens and Sphaerophorus meZanocarpus apparently need a nearly continuous atmospherical humidity. For ecological and floristical data on the humid lower superparamo Ln the Sierra Nevada del Cocuy, I refer to Cuatrecasas & Cleef (1978). Apart from conspicuous Caryophyllaceae and Draba spp. (e.g. Draba hammenii ), the floristic composition and physiognomy of the u p p e r s u p e r p a r a m o appear to be more or less similar to that on the opposite dry side of the Sierra Nevada del Cocuy. Botanical fieldwork was carried out here only occasionally. Paramo vegetation zonation, upper forest line, altitude and climate The altitude of the various paramo vegetation zones in the Colombian Cordillera Oriental has been studied in detail in the Paramo C6ncavo (d-ry side) and in the headwaters of the Rio Casanare (humid side), both located in the Sierra Nevada del Cocuy (Fig. 9). The vegetational differences on the dry side and the humid side of the mountains are prominent in the Cocuy region, which may serve as a .model for paramo zonation. Fig. 9 shows that the paramo vegetation zones in the Sierra Nevada del Cocuy are arranged asymmetrically. On the dry side of these mountains, continuous strong isolation and the resulting warm air rising from the inter-andean deep and dry Rio Chicamocha valley is a daily event, that causes a distinct upward shifting of the local zones of the high Andean vegetation. A lower bunchgrass zone is rare to absent. The high ,watershed in this area nearly completely prevents the movement 路 of humid air f rom the Casanare slopes towards .the dry mountain s~de. On the humid side of the Sierra Nevada del Cocuy, the timberline forest mainly consists of Weinmannia roZZottii Killip (Cunon.), a simple-leaved species, heavily loaded with epiphytes, e.g. Herbertus juniperoideus, HymenophyZZum spp., Ericaceae, etc.; trees of BruneZZia coZombiana Cuatr. (Brunell.), CZusia sp. (Guttif . ) and Hedyosmum sp. (Chloranth.) are also present, with an underlayer of the broad leaved bamboo NeuroZepis aperta (Munro) Pilger , On the dry side of the Sierra Nevada del Cocuy, however, forestline woods mainly consist of Compositae (e.g. DipZostephium spp., Gynoxys spp.), and Rosaceae (e.g. HesperomeZes cf. goudotii, PoZyZepis quadrijuga) and BuddZeia Zindenii, while trees of pinnate-leaved Weinmann~a occur, but are rare. Sheltered places, evidently offering favourable environmental conditions, contain patches of HesperomeZes cf. goudotiana forest up to 3800 m and dwarfforests of PoZyZepis quadrijuga and Gynoxys spp. up to 4100 m.

so Small patches of dwarfed trees of Diplostephium r homboidale and Valeriana arborea are present here, even up to 4400 m. On the humid slopes, dwarfed groves of Gynoxys albivestita and Valeriana arborea are found up to 4250 m, and one consisting of Senecio f los -fragrans var. frigidophilus up to 4300 m. Although the floristical composition of the upper forests on either side of the Sierra Nevada del Cocuy is quite different. The two types are continuous, closed, well-developed, thick-stemmed timberline forests. Thus, a comparison of their higher parts is relevant for determining the actual upper forest line in the Sierra Nevada del Cocuy. Our timberline obeservations there largely agree with those of Cuatrecasas (1958) in other locations on the dry side of the Cocuy range. Environmental conditions in the other, lower paramos in the Cordillera Oriental are quite different. Consequently, on atmospherically dry slopes the re the upper forest line is generally lower and running at (3000) 3200 3300 m. These timberline forests mainly consist of pinnate-leaved Weinmannia spp. ,especially W.-tomentosa L.L, mixed with composites and Melastomataceae, and occasionally Rosaceae (Polyl epis quadrijuga, Hesperomeles sp.). In the dry upper Chicamocha valley the timberline forests are mainlv Quercus sp. (W side) or pinnate-leaved Weinmannia fagaroides HBK (E side) according to Vander Hammen ,et al. (1981) and pers. comm. Unfortunately few original mountain forests without human interference remain. On the atmospherically humid slopes the upper forest line is generally slightly higher and situated at 3300 - 3500 m. Timberline forests there consist mainly of Weinmannia (pinnate and simple-leaved species), with frequent (co-) dominance of Compositae (Diplostephium spp.) and Melastomataceae (Miconia spp.) and occasionally with either Polylepis quadrijuga or Escallonia myrtilloides var. myrtilloides . The atmospherically humid Magdalena valley slopes forests reaching up to the timberline at 3400 m in the Paramo de Guantiva (Santander). The zonal upper subparamo dominated by Arcytophyllum nitidum generally reaches up to 3500 m on the atmospherically dry and humid slopes. Thus, the upper forest line in the Colombian Cordillera Oriental appears to be mainly determined by thermal conditions. On the atmospherically dry side of the mountains, minimum night temperatures are considerably lower than at the same height on the opposite humid side, where the upper forest line generally reaches slightly higher. Daily temperature amplitudes thus are largest on the dry side of the mountains. On the humid slopes, rain clouds and frequent fog cause oligothermic conditions, viz. low temperatures and a minor diurnal temperature range. The vertical distance between the upper forest line and the lower paramo vegetation zone on either side of the Cordillera is probably greatest in the Sierra Nevada del Cocuy. It is not quite clear why the paramo belt on the humid SE slopes there reaches so far down. Extreme humidity causing boggy substrate, might have a lowering effect on the upper forest line. For further discussion I refer to Van der Hammen et al. (1981) and Vander Hammen & Cleef (in press). The duration of the total period of high atmospherical humidity (including periods of precipitation and fog) in relation to the total annual precipitation apperently determines the bamboo cover in the lower paramos (Fig.80 ). In the upper superparamo, humidity conditions appear to be nearly similar on both sides of the Sierra Nevada del Cocuy. The special floristic composition and the larger cover of the vegetation at the grass paramo-superparamo border, especially on the humid side of the Cordillera, may explain the presence of a marked upper condensation zone at

4000- 4200 m. Gradstein et al. (1977) and Cleef (1978) reported on the rich vegetation of the condensation zone of 4000 m on the Nevada de Sumapaz. Tnis interesting locality still remains as the best example of its kind in the Colombian and Venezuelan Andes. Weischet (1969) published an outstanding climatological study of the Colombian Andes, and he was probably the first to demonstrate such condensation levels at lower altitudes. Guhl (1974) reported three vertically arranged cloud belts, the upper one in the high paramo. Lauer & Frankenberg (1978) and Lauer (1979) described condensation zones from lower levels in the Mexican Mountains and the Ecuadorian Andes. According to these authors, condensation zones are defined as vertically restricted zones. Regarding the paramo belt, they locate the maximum precipitation and duration of fog. Clearly, these zones a~e of great biological and ecological importance.

SHORT SURVEY OF THE ZONAL COMMUNITIES Introduction Ahead of a future final tabular arrangement of the releves according to the Zurich-Montpellier method, a synopsis of the zonal paramo vegetation may be presented in order to complete the general picture of the vegetation of the study area. This outline is based upon preliminary tables (of SwallenochZoa communities) and from not yet completed "differentiating tables", in which the releves are arranged in "vegetation units" or communities on basis of their floristic, and- to some extent- their physiognomic and ecologic similarities, but without establishing their synsystematic rank (Mueller Dombois & Ellenberg 1974). The communities have been numbered consecutively. A limited number of species is found in all altitudinal zones of the paramo, e.g. Bartsia sp(p:), Grammitis moniZiformis, Hypochoeris sessiZiflora, LuzuZa cf. racemosa, Pernettya prostrata, Senecio Vqccinioides; the bryophytes:

Andreaea rupestris, Bryum argenteum, PoZytrichum juniperinum, Racomitrium crispulum, AnastrophyZZum Zeucostomum, StephanieZZa paraphyZZina and the lichens CZadia aggregata, CZadonia andesita, C. chZorophaea and Cora pavonia. The bryophytes are widely distributed species with pioneer character: "colonists" and "annual shuttle species" (During 1979). Cora pavonia and Bryum argenteum continue downslope into the warm tropical belt. The lower part of the paramo belt comprises both the subparamo and the grass paramo. It contains characteristic endemic vascular genera belonging to the paramo element'(Cleef 1979a): e.g. Bucquetia, Aragoa, CastrateZZa, Espeletia, Libanothamnus, PZutarchia, PurpureZZa and SwaZZenochloa. Th~- stemrosettes of EspeZetia and EspeZetiopsis are most common and

represented by a large number of endemic species. Recently Cuatrecasas (1979) reported 17 species of EspeZetiopsis and 34 species of EspeZetia for the Colombian Cordillera Oriental. Species of EspeZetiopsis generally abound in the driest habitats, most of them on sandy soil, in the zonal paramo. These species are nearly absent in the bamboo paramos. Species of EspeZetia, however, grow on dry to humid sandy, clayey and peaty soils and are only absent in deep and wet bogs, located e.g. on former lakes.

CaZamagrostis effusa is abundant in the zonal paramo, except in the superparamo, in the dense shrub paramo and in the wettest SwaZZenochZoa stands. This species is the most important tussock of the paramos of the Colombian Cordillera Oriental, forming the "pajonales" on the dry side of the mountains. This bunchgrass species is also found in other north-andean paramos from

Venezuela to Central Ecuador, but is probably absent in the Costa Rican paramos (Dr. J. Cuatrecasas, in litt . ) As pointed out earlier (Cleef 1978) SwaUenochloa tesselata is only found in zonal paramo vegetation on the humid side of the mountains with the wettest climate. Towards higher altitude (upper grass paramo) or in less humid climatological conditions Swallenochloa gradually becomes restricted to always humid or wet valley floors or to bogs on slopes and in depressions. Finally Swallenochloa is restricted to humid valley floor bogs with vegetation belonging to the azonal communities (Fig. 79). The climatologically most humid paramos have been studied on the outer slopes above the cloudforest line, e.g. on the SE side of the Sierra Nevada del Cocuy in the headwaters of Rio Casanare, in the paramos of the Perra de Arnical about 5 km N of Vado Honda (Sogamoso-Pajarito road), in the lower part of the Chuza valley between the Paramo de Palacio and the Paramo of Chingaza, and on the eas tern slopes of the Nevada de Sumapaz and its surroundings. The zonal communities will be treated below in sequence of altitude from the subparamo up to the superparamo, indicating whether they are found in dry or humid paramo climates. Only the communities, observed by the author, are treated, though references will be made to information in . literature . Numerous releves were made in paramo vegetation, with noticeable human activities. Such vegetation contains a number of species from the next higher paramo zone, or it may be more or less completely temporarily replaced by a type of vegetation similar to the zonal vegetation of the next higher belt. In the latter case, the physiognomy and floristics of the replaced vegetation will be discussed under the higher paramo zone. The following zonal communities (I - 28) have been recognized. Most of them correspond probably closely to syntaxa, which will be described in the near future. Most characteristic taxa in the following descriptions are expected to become diagnostic taxa then. Two syntaxa, however, the Acaeno-Plantaginetum sericeae (18) and the Loricarietum complanatae (21) could already be named and described formally.

THE SUBPARAMO S h r u b

p a r a mo

(or

1 o w e r

s u b p a r a m o)

The shrub paramo is dominated by Ericacae, Compositae Melastomataceae. Its floristic composition varies considerably according to geographic position and altitude, humidity, land form, soil factors, and human activity. A number of shrub communities can be recognized. In the study area Bucquetia is the most characteristic genus for the shrub paramo and is mostly found as a shrub or dwarf tree. Bucquetia vernicosa is found from the eastern side of the Sierra Nevada del路 Cocuy northward; Bucquetia glutinosa is the common species in the southern part of the Colombian Cordillera Oriental (Fig. lOa). In general, more genera and species of Melastomaceae with a higher cover seem to be present in shrub paramos on the most humid side of the mountains, than on the drier slopes. Other characteristic shrub species are: Purpurella grossa~ Eupatorium (Ageratina)

tinifolium, Aragoa lycopodioides, Gaultheria ramosissima, Symplocos t 路heiformis, Ugni myricoides and a number of shrub species of Hypericum, e.g. H. l.ycopodioides, H. papiUosum, H. magniflorum ..

53 The lower pararnos appear to be most strongly affected by human activities. The shrub pararno suffers most from clearing for pasture, growing potatoes, and cutting for fuel . Only the most inaccesible areas remain more or less intact. In comparison to the higher pararno zones, little is known of the vegetation of the shrub pararno . Previous phytosociological studies dealing with the shrub pararno of the Colombian Cordillera Oriental include those of Cuatrecasas (1934) , Vander Hanmen & Gonzalez (1960a, 1963), Vander Hammen et al. (1981), Van der Hammen & Jaramillo, (in prep . ), Lozano & Schnetter (1976) and Rangel (1976) . As the open pararno vegetation was the main purpose of our studies, only a few releves were sampled in the shrub pararno .

Shrub pararno with Espeletiopsis Fig . II

This is a rather open low shrub and dwarfshrub vegetation up to 2 . 5 rn high and is extremely rich in leptophyllous species . Espeletiopsis species, e.g . E. corymbosa, E. garciae, E. pleiochasia, E. muiska, E. jimenez-quesadae, are geographical vicariants and they cover from 10 to 40% of the area. Common species are : Bucquetia glutinosa, Brachyotum strigosum, Clethra fimbriata, ,

Bulbostylis tropicalis, Gaultheria rigida, Castilleja integrifolia, Lycopodium complanatum var . tropicali s , Befaria spp . , Macleanea rupestris. The community occurs on steep (20°-35°) slopes, with 20-100 ern thick brownish clayey-sandy or sandy, moderately acid soil (pH 4.5-4.9). Floristic composition is rather diverse , and it is expected that more vegetation units can be distinguished when more data become available. Espeletiopsis formations were studied between 2850 and 3790 rn (generally between 3000 3400 rn) on the dry side of the mountains , where they occupy rather small, mostly convex , well-drained areas , frequently near sandstone outcrops . The greatest ·f loris tic affinity is with Macleanea rupestris shrub, also reported (Lozano & Schnetter 1976) from ridges and other well-drained areas covered with thin soil. The position of the Espeletiopsis shrub community is intermediate between the dense shrub pararno vegetation and the Arcytophyllum nitidum dwarfshrub communities . 2.

Senecio vaccihioides subpararno shrub Fig . 12

This type of zonal leptophyllous subpararno shrub has only been studied in the Sierra Nevada del Cocuy and its southern extension in the Paramo de Chita and Pisva . Although present on the dry side as well as on the humid side of this range , a larger area seems to be covered on the dry side, especially on the Alto de la Cueva and in the high valley of Lagunillas (3750-4000 rn) . Senecio vaccinioides shrub . there is up to 2 . 5 rn high, and generally present on the steep, well-drained slopes of valleys and on moraines. The dark brownish sandy and stony soils are thin (10-25 em), with one measured pH of 5 . 3. Lower Senecio vaccini6ides shrub (1 . 5 rn high) at 3530 rn in the humid Paramo de Pisva was also found on steep slopes on more humic, thicker, clayey soil (pH 4.7 in the upper layer) . Thickets were observed between 3400 and 3550 (3750) rn and may be associated with Swallenochloa The main floristic difference between both stands is found in the ground layer. Bryophytes cover half or more of the surface . Hygrophytic mosses, e.g . Pleurozium schreberi,

Chorisodontium

sp., Campylopus jamesonii anu Leptodontium wallisii, which abound on the humid slope, are replaced by the clearly less hygrophytic Hypnum amabile and Thuidium peruvianum in the composite thickets on the dry side of the mountains. Senecio vaccinioides is found from Central Ecuador up to the Costa Rican paramos, and was also noticed as a patchy dwarfforest formation in the Parque Los Nevados, Colombian Cordillera Central (Cuatrecasas 1934; Cleef et al., in press). Under nr. 81 and 96 other Senecio vaccinioides communities in the study area are discussed. 3.

Eupatorium (Ageratina) tinifolium shrub Fig. 13 photo: Gradstein et al. 1977: plate 2, A; lit.: Vander Hammen et al. 1981

Well-developed stands of the mesophyllous Ageratinetum (= Eupatorietum) were studied in 1967 by Van der Hammen & Jaramillo (in prep.) in the headwaters of the Rio Casanare (Paramo de Pisva) between 3300 and 3700 m. Rangel (1976) reported a community of Eupatorium tinifolium and Gynoxys cf. pendula from the Paramo de Pisva at 3400 m. The present author visited the above mentioned stands and noted as associated species Baccharis

tinifoliae (ined.)

prunifolia, Escallonia myrtilloides, Hypericum lycopodioides, H. laricifolium, Gynoxys sp., Ribes sp., Vallea stipularis, Oreopanax sp., Miconia salicifolia and shrubby species of Senecio. Miconia sect. Cremanium, Cestrum and Bucquetia are frequent in the vicinity of the wet . cloud forest line. Eupatorium tinifolium .thickets were also locally reported from the valley of Q. El Play6n, Sierra Nevada del Cocuy, between 3400 and 3675 m; from the humid north~rn side of the Paramo del Almorzadero between 3400 and 3700 m; from the humid shrub paramo E of Bucaramanga , from the Paramo de Palacio, and from the R1o Nevado and the Q. Sitiales valley in the Paramo de Sumapaz between 3300 and 3450 m. These thickets were also observed near the upper forestline in the Cordillera Central of Colombia (Cleef et al. , in press). Judging from herbarium data,Eupat01•ium tinifoliilm must be present in the Colombian Andes between 2400 and 3800 m. · In general · terms Eupatorium tinifolium groves are characteristic for the humid side of the mountains above the upper forestline. 4.

Shrub and dwarfforest of the "Vaccinion floribundi" Cuatrecasas 1934 photo: C'uatrecasas 1934: plate XIX; 3 photographs in Van der Hammen & Gonzalez (1960a, 1963)

Cuatrecasas (1934) first mentioned this alliance for the combined humid ecotonic nanophyllous and sclerophyllous shrub and dwarfforest, distributed in patches above the forestline in the Paramo de Guasca (3200-3550 m) . in the Cordillera Oriental and on the Nevado del Tolima (3500-3800 m) in the Colombian Cordillera Central. Characteristic are Vaccinium floribundum,

Miconia ligustrina, Miconia salicifolia, Rapanea dependens, Escallonia myrtilloides, Senecio vaccinioides and Brachyotum strigosum. Vander Hammen & Gonzalez (1960a, 1963), in association with J. HernandezCamacho, reported similair communities in small protected valleys between 3500 and 3600 m in the Paramo de Palacio. Lozano & Schnetter (1976) published three releves from residual humid dwarfforest in the Paramo de Cruz Verde, E of Bogota at 3400 m. These stands on sloping ground are rather mixed as

regards their floristic compos~t~on. Dwarftrees up to 3 m high of Gaultheria anas tomosans and Hyperi cum goyanesii shrub were noticed among the dominant species. In the ground layer, Plagiochila spp. and Pleurozium schreberi are dominant. Own observations in a similar shrubby stand (2-3 m high) on thick humic peaty to clayey, slightly sloping soil (pH 4.3 in the upper layer) at 33 70 m in the atmospherically humid Paramo de Palacio (rel . 136) revealed that in the upper shrublayer Swallenchloa is dominant and Vaccinium floribundum, Hypericum lycopodioides and Bucquetia glutinosa are subdominant (cover IS to 25 %). Low trunks of Blechnum loxense in the dwarfshrub layer cover about 30 %. Plagiochila sp. (5139) as dominant and Hypnum amabile together with Hydrocotyle gunneri folia were subdominant in the ground layer ( cover resp . 40 , 30 and 20 %). There are many hygrophytic species , some of which belong to the upper Andean forest element. In summary , this type of shrub paramo of ecotonic dwarfforest seems most common on the humid side of the Colombian Oriental betwe en 3200 and 3600 m. This vegetation type has been studied only in the southern paramos (Guasca to Sumapaz). The community is rich in bryophyte species, both terrestric and epiphytic, and patches of Sphagnum magellanicum peat may be developed here.

Arcytophyll1gn nitidum d w a r f s h r u b

p a r a m o

The zonal vegetation of the upper subpararno is best characterized by bryophyllous rubiaceous dwarfshrub of Arcytophyllum nitidum. The vegetation is mostly three-layered: I) a dwarfshrub layer, 2) a herb-graminoid layer , and 3) a ground layer of bryophytes and some low h e rbs . The herbaceousgraminoid layer is better developed in open dwarfshrub and mainly consists of photophytic species, e.g. Castratella spp., Rhynchospor a paramo~hm , Oreobolus obtusangulus ssp. rubrovaginatus,which occur in open pararno on shallow soil , just as: Bartsia spp. , Hypochoeris sessiliflora , grasses, Rhynchospora macrochaeta and Hypericum strictum. Mosses dominate the reduced bryophyte layer (1-10 %â&#x20AC;˘cover) on the dry side , but mosses and/or hepatics attain almost 100 % cover on the humid side of the mountains . Lycopodium contiguum and species of Gaultheria ~vi th glandular hairs are the most common and characteristic accompanying species. Geranium multiceps is frequent too , this conspicuous species is also found in boggy Swallenochloa tesselata paramo with Puya goudotiana and species of Sphagnum at the same altitude. Other characteristic vascular species, reaching more or less th e ir optimu~ in this dwarfshrub zone, are: Lourteigia (Eupatorium) microphylla,

Sporob@lus lasiophyllus, Diplos tephium phylicoides, Masdevallia coriacea, Bacchdris rupicola, Spiranthes vaginata, S. coccinea, Tofieldia falcata, Dip lostephium huertasii, Lycopodium camp lana tum va r . tropicum, Achyroc line lehmannii, Gaultheria anastomosans, Gaylussacia buxi folia, Epidendrum chioneum, Odontoglossum lindenii, Paepalanthus alpinus , P. andicola var. villosus, P. paramensis, Pernettya hirta, Verbesina baccharidea, Miconia parvif6lia, Br achyotum strigosum . Noteworthy is that several of these spe c ies have the same distribution from the southern end of the Paramo de Guantira to the northern Sumapaz, e.g. Diplostephium phylicoides (Fig. JOb), Verbesina baccharidea, Miconia parvifolia. The characteristic vascular genera mainly belong to the nee-tropical Andean element (Cleef 1979b). The shallow soils are clayey to sandy and moder a tely to strongly acid

(pH 5.2-4.1). Most of the stands are found on steep, well-drained slopes.

ArcytophyZZum nitidum vegetation is common and attains a considerably higher cover on the dry side of the mountains . This rubiaceous species occurs throughout the paramos of the Colombian Cordillera Oriental from 2800 to 4080 m. It is also known from Venezuelan paramos . Phytosociological data on Arcytophy ZZum nitidum vegetation were published earlier by Cuatrecasas (1934), Lozano & Schnetter (1976) and Sturm (1978).

Dense ArcytophyUum nitidum dwarf shrub Fig. 14

Dense Arcy t ophyUum nitidum dwarfshrub vegetation, if undisturb e d , is up to 1.20 m high and covers about 60 to 80 % of the surface. Dominant ArcytophyZZum nitidum shrub largely determines the aspect of the upper subparamo. Br yum cf. grandifo Zium and Lycopodium contiguum are present and r e ach high cover valued under the neariy closed dwarfshrub layer. Because of the shrubby character of the stands, less photophytic species are found than in other more open ArcytophyZZum communities (6, 7, 8). In comparison with other Ar cytophyZZum ni t i dum communities, this one is the poorest in species . Mosses and lichens cover about 5-12 %. This dwa rfshrub community is mainly present on moderately steep slopes (15째200) with black-brownish sandy soils not thicker than about half a meter. The pH of the upper brown sandy or black sandy clayey soil layer is 4.4 to 5.0. This dense rubiaceous dwarfshrub vegetation is mainly found on the dry side throughout the study area between 3100 an 3600 m. In the Paramo C6ncavo in the Sierra Nevada del Cocuy this kind of dwarfshrub vegetation is well developed between 37.50 and 3900 m. Mas devaZZia coriacea and an unknown species of ScaphosepaZum (10019) are associated orchid species .

Dwarfshrub of Arcy t ophy ZZum ni tidum with Spor obo Zus Zasi ophy ZZus, and Achyr ocZine Zehmanni i Fig. IS lit.: Lozano & Schnetter 1976.

The ArcytophyZZum nitidum cover is about 30 % in this open dwarfshrub veg etation . Locally other woody species may contribute to the dwarfshrub layer, e.g. GayZussacia buxi folia Hyp er icum juniperinum and VaZeriana t riphyl Za . SporoboZus ZasiophyZZus (cover up to 35 %) and to a lesser degree Achyroc Zine Zehmannii, Gaultheria rigi da, Lobe lia tenera, DipZoschistes sp. and Ver besina baccharidea reflect more x eric conditions PaepaZanthus paramensis is another cushionplant, which is most frequent in this vegetation (on both sides of the mountains). Cast rateZZa piZose ZZoides is generally present, in some places associated with Rhynchospora paramorum Soils are thin (10-30 em), brownish , coarse sandy, and in many places stony (pH 4 . 6-5.2) . The open dwarfshrub is found on well-drained and exposed steep slopes (5-44째; mean 25-30째), also on stony ridges and in summit areas . This type apparently is present throughout the subparamos of the Cordillera Oriental and was studied from 2925 to 3630 m. The stands in the humid subparamos are found on the edaphically driest, steep places, where bamboos are absent .

Dwarfshrub of Arcytophyllum nitidum with Diplostephium phylicoides Fig. 16, lOb (also 52) lit.: Lozano & Schnetter 1976 This dwarfshrub vegetation covers at least half of the area or more

Arcytophyllum nitidum covers 30 to 70 %. Diplostephium phylicoides (Fig. lOb), which is absent in the other Arcytophyllum nitidum communities, may contribute up to 30% of the dwarfshrub layer. Gentianella corymbosa and lichens, e.g. species of Cladonia subg. Cladina, are conspicuous. Blechnum loxense and Oreobolus obtusangulus ssp. rubrovaginatus indicate less xeric environmental conditions. Swallenochloa, however, is almost absent, Castratella piloselloides is connnon; Rhychospora paramorum occurs in most of the releves. The soils are thick, humic, black sandy to clayey, SO to more than 120 em thi ck. The pH of the strongly acid toplayer is 4.1 to 4.7. The community is found on sloping to moderately steep ground. This type of subparamo dwarfshrub has only been found near Bogota between 3275 and 3550 m, in climatologically dry as well as in more humid subparamos. Some more rel eves (belonging to this type) were mentioned by Lozano & Schnetter (1976) and Sturm (1978). This connnunity is floristically heterogeneous, and probably will be subdivided in several syntaxa when mo re data become available. 8.

Communities of Arcytophyllum nitidum in bamboo-dwarfshrub paramos Fig. 17

Arcytophyllum nitidum d\varfshrub, of which unfortunately a few releves only are available, is least represented on the (pe r)humid side of the路 mountains. The different communities will be briefly characterized. Swallenochloa tesselata and Xyris acutifolia are scarce or absent in zonal vegetation on the dry side of the mountains, but they are well represented here. Species characteristic for the dry side of the mountains are almost absent, and their cover decreases towards the (per)humid paramos: e.g. Polytrichum juniperinum, Castilleja fissifolia, Altensteinia fimbriata, Baccharis tricuneata, Hieracium avilae and species of Lourteigia and Espeletiopsis . The bryophyte layer is well developed and the cover of mosses and liverworts increases up to 100 % t.owards the upper perhumid cloudforest line. In closed stands of Arcytophyllum nitidum, which are relatively rare on the wet side, Swallenochloa is dominant in the dense bamboo dwarfshrub fieldlayer, and this dwarfshrub is found on protected sites near the c loudforest border. Floristically, the open Arcytophyllum nitidum - Swallenochloa -vegetation is characterized by Sphagnum spp., Spiranthes coccinea, Diplostephium

huertas路ii, Tofieldia falcata, Rhacocarpus purpurascens, Campylopus cucullatifolius, Oritropium peruvianum, Pinguicula elongata, Kurzia verrucosa, etc. ,which are nearly absent in other Arcytophyllum nitidum connnunities. Castratella spp., Rhynchospora paramorum and Oreobolus obtusangulus ssp. rubrovaginatus are elements of the open lower part of the paramo belt, and they are opulent in the moderately humid paramos. In open Arcytophyllum nitidum dwarfshrub (5-35 % cover) in the bamboo paramo, at l eas t two different typ es may be distinguished. In one the (aero-) hygrophytic moss Rhacocarpus purpurascens is most common, while in the other more boggy one Sphagnum species are prominent. This last mentioned type has only be en studied in the headwaters of Rio Casanare just above the uppers forestline. The type with Rhacocarpus is present both in humid and in perhumid paramos (2900-3650 m). Rhynchospora paramorum (Fig. JOe) is a conspicuous

constituent (30-75 % cover) in the humid paramo where it is r eplaced by a rather low "grassy" zonal vegetation . Dis t erigma errrpe tri fo~ium, Tofie~dia fa~cata and locally Castrate~ ~a r osea and Nephopter is ma~onii are characteristic species also . Sphagnum spp. , e. g. S . sect . Ma~acosphagnum (9910), and other commonly associated bryophytes are present wi th a lesser cover. Stands in the paramos near Bogota (Cruz Verde - Sumapaz) contain Dip~ostephium phy ~ico i des as an associated species. 9.

Gau~theria

r amosissima and Disterigma car acasanum

empetrifo~ium

dwar fsh rub with

Arcytophy~~um

This presumably zonal dw a rfshrub community has only been noticed in the headwaters of the Casanare river , in the San Luis valley of the upper Play6n stre am at 3500 m. Dwarfshrub and low shrub dominated by Eri caceae and liverworts are found _on stony moraine s with steep slopes and shallow humic sandy soil of 10-15 em with a pH of 4.6-5.0 . The height of the stratum is only about 40 em, but a number of low shrubs native to the shrub paramo (e .g . Gau~the ria ramosissirna, ~ycopodioides ) indicate

Ar agoa lycopodioi des, Rapanea dependens , Hypericum

more favourable temperature conditions on these moraines than in the surrounding open Sphagnum bogs . Without gr a zing and trampling by cattle and human activities this community may develop into a shrub paramo. The presence o f some cloudforest liverworts: e . g. Leptoscyphus porphyrius and Ompha~anthus fi~iforrnis (Gradste in et a l. 1977) i s conspicuous . Disterigma empetrifo~ium ( 20 -30 % cover) and Arcytophy~~um caracasanum (up to 35 % cover) are found on s ha llow stony steep soils predominantly in the humid ]:raramos of the Colombi an Cordillera Oriental. o路t her charac teristic va scular spe c ies in the bamboo dwarfshrub paramo in c lude: E~aphog~o s sum spp . , Ugni rnyricoides , Gau~theria anastornosans, G. sp . nov. (9120B) , Epidendrum chioneum, and Eupatorium (Ageratina ) vaccini oides. Ca~arnagrostis ef fu sa is not cons picuous; Swa~~enoch~oa tesse~ata patches may cQver up to 35 %. A thick mass of terrestric and epiphytic liverworts associat ed with Or opogon sp. (9131) covering about 75 % refle ct s pe rmanently humid climatological conditions (Fru~~ania sp. (9143)) . Everniastrum cirrhat um is the most common e piphyte. Lepidozia a~s tonii , a rare liverwort species , has been colle ct e d in this area onl y.

THE GRASS PARAMO The grass paramo of the Colombian Cordill e ra Orient a l contains the zonal graminoid communities associate d with species of the Espe~etiinae . These communiti e s are found in a zone, limited below by the dwarfshrub-dominated s ubparamo and above by the lowe r limit of the s uperparamo. CaZamagrostis ef fu sa i s the most prominent paramo bunchgr a ss . In the climatolog ica lly humid paramo s this s pecies may be partly or entirely replaced by dwarfed Swa~~enoch~oa tesse~ata bamboo (Fig . 6 , 8) . The dominant grasses Ca~arnagrostis e ffusa and Swa~~enoch~oa te s se~ata are endemic species of the northern Andean paramos; at the generic level they belong r e sp. to the wide temperate and the paramo e lement . Ca~amagrostis effusa is assigned to the se ction Deyeuxia of Ca~arnagrostis , which is mainly distributed in the cool s outhern hemisphere and on tropi cal hi gh mountains .

Numerous taxa are present in the grass paramos. The most important are e.g. CaZamagrostis effusa, EspeZetia, EspeZetiopsis, HaZenia, Bartsia, Pernettya prostrata, Vaccinium fZoribundum var. ramosissimum, CaZamagr ostis bogotensis, OreoboZus obtusanguZus ssp. rubrovaginatus , CZadonia isabeZZina,

CZadia aggregata, GongyZanthus Ziebmannianus, StephanieZZa paraphyZZina, AnastrophyZZum Zeucostomum, CampyZopus spp. (e .g . C. chrismarii var. subobZongus, C. cZeefiiJ .

The number of species in the grass paramo increases considerably towards lower parts. For example: the open CaZamagrostis effusa - EspeZetiopsis coZ~mbiana bunchgrass paramo at 4400 m on the dry side of the Sierra Nevada del Cocuy contains 18 species (rel. 455). In the lower parts of the upper bunchgrass-dominated paramo near 4100 m about 25 species were recorded on both sides of the Cocuy range. On the average about twice as many species are present in the lower bunchgrass paramo and three times as many in the lower bamboo paramo, compared to the upper bunchgrass par~mo at 4100 m. The closed bunchgrass paramo is rather poor in species. A special, permanently humid microhabitat is found here between the tussocks in the shade of the bunches. Burning of the bunchgrass-dominated paramos has a strong effect. The grass cover is considerably reduced and photophytic taxa become predominant in the newly open and dri e r habitat. Previously, these were unobtrusive as small rachitic . or as viable seeds in the deep shade under the bunches. After burning they develop rapidly and soon reach the ir reproductive cycle, from flowering to fruiting, often several times per year. For example , brightly reddish flowering CastiZZeja integrifoZia may determine the aspect a few weeks after the burning. PaepaZanthuskarstenii, ArcytophyZZum muticum, Eryngium humiZe, CastrateZZa, Bartsia, Carex tristicha e.g. become more conspicuous later on. Hygroshytic bryophytes disappear or may s urvive close to the tussocks. Xe rophytic and/or photophytic liverworts, e.g. StephanieZZa paraphyZZina, GongyZanthus Ziebmannianus and Isotachis multiceps are then common on the bare mineral soil.

B a mb o o

p a r a mo

As indicated before, releves from the bamboo paramos have not been analysed as much in detail as those from the bunchgrass paramo , and the main communities can be treated summarily only . Most releves were sampled in the lower pamboo paramo and only some of them are from the upper bamboo-bunchgrass paramo. Therefore, no distinction was made below between lower and upper parts of the bamboo paramo, as most communities belong to the lower one. Zonal highaltitude bunchgrass-bamboo paramo communities are described under 12 and 13a. The bamboo paramo as defined in a zonal sense comprises all open zonal gramif oid vegetations with SwaZZenochZoa. Bunches of CaZamagrostis, sometimes of Festuca cf. doZichophyZZa or Cortaderia sericantha are usually associated. The high degr ee of humidity is well reflected by the proportions of the cover of CaZamagrostis and SwalZenochZoa . Bamboo is generally predominant, but with less humid environmental conditions CaZamagrostis effusa becomes predominant (Cleef 1978). In perhumid lower bamboo paramos , SwaZZenochZoa tesseZata is dominating 'in the zonal ve getation, even in the driest places on top of well-drained ridges and crests (Fi g .79).~ Bunchgrasses, e.g . CaZamagrostis effusa and Festuca cf. doZichophyZZa were found with a lesser cover in nearly all releves. Localities on the wet slope with these atmospherically extreme humid paramos were mentioned before ." Bamboos are common on the slopes, but do not reach the highest parts or the driest places in a less humid climate. Thu~ SwaZZenochZoa tesseZata may only be found in azonal boggy. valley

floor communiti e s in the bunchgrass paramo. There is a gradual transition be t ween bamboo and bunchgrass paramos , and it is rather difficult to distinguish floristically and ecologically pure bunchgrass paramo from grassland with some clumps of Swallenochloa tesselata. Swallenochloa tesselata in zonal vegetations reaches up to 4150 m. In most places a belt of about 100 m vertically with pure Calamagrostis effusa sward is found above the Swallenochloa paramo (see 20). Charac t er i s tic and common taxa of the bamboo paramo proper are: Swallenochloa tesse lata, Calamagrostis effusa, Espeletia spp., Bartsia spp . , Oreobolus obtusangulus spp. rubrovaginatus, Oritrophium peruvianum, Halenia spp., Rhynchospora macrochaeta, Carex pichinchensis, Hypericum lancioides , (H. garciae), Pernettya prostrata var . purpurea, Arcyiophyllum muticum, Nertera granadensis, Breutelia spp., Riccardia spp . , Lepidozia s pp. (e .g .

Lepidozia auriculata) , Cladia aggregata, Rhacocarpus purpurascens, Adelanthus lindenber gianus, Anastrophyllum spp ., Campylopus spp., Cladoni a andesita and Cladonia subg . Cladina. 10.

Community of Swallenochloa with Sphagnum and/or Breutelia Fig. 18 (also Fig. 10 and 51) photo: Gradstein et a l. 1977, plate ID

Peat moss - bamboo vegetation on boggy and sloping valley floors and distributed on the humid slo1JeS tends to be zonal. This a ctually azonal vegetation is common in the most humid paramo s. Under less humid conditions, it is found in slight depressions on the slopes , and in many places it grades into well-draine d (bamboo- ) tussock grassland. In general, Breutelia cover is larger in higher places , while that of Sphagnum is proportionally less . The floristic differences between slope and valley floor communities are not conspi cuous. Sphagnum magellanicum and S. cuspidatum for example prefe r level habitats on deep bogs; Oreobolus obtusangulus is mostly found on slope bogs on peaty mineral soil. Festuca cf. dolichophylla is a common tussock here. Characteristic bryophyte species include: Gongylanthus granat:ensis, G. innovans, Adelanthus lindenbergianus, Anastrophyllum spp., Telaranea nematodes, Blepharostoma trichophyllum, Breutelia

allionii, B. chrysea, Leptoscyphus cleefii, Sphagnum magellanicum, S. sancto- josephense, S. oxyphyllum, S. cuspidatum, S . cyclophyllum and some sma11 herbs as Niphogeton lingula, Eriocaulon micr ocephalum, Senecio subruncinnatus. Glossidium aversum, Cladonia furcata, and Cladonia (s ubg. Cladina) confusa are common lichens. Vicariating species of Espeletia are e.g. E. summapacis, E. grandiflora var., E. lopezii var. major,E. incana and E. murilloi . In the upper reaches at 4000 m, e.g. in the Paramo de Sumapaz , a number of species of the upper condensation zone may be found in boggy, dens e Swallenochloa-Breutelia slope vegetation with Espeletia summapacis, e.g.

Lachemilla nivalis, Luzula gigantea, Mantia cf.meridensis, Valeriana plantaginea, Bartramia angustifolia, Herbertus subdentatus, and composite shrub of Senecio vernicosus and Diplostephium alveolatum. Peat growth started here abo u t 5000 years B. P. (COL 266- GRN 8457 - 5090 B.P. Âą 25) ; this date is based on radiocarbon dating of the base of the peat on the Rabona watershed at 4000 m. In view of similar and other ages for paramo peat, most of these bogs must have originated about 5000 years ago, or some 3000 years ago at thebounderiesof Andean pollenzones VII an VIII.when the climate b ecame colder and more humid (Van der Hammen & Gonza lez , 1960b; Van der Hammen, pers . comm.).

Bamboo commun~t~es with Sphagnum and/or Breutelia prefer moderately acid (pH 4.6-5.4), humid, thick peaty soils. They are common to all humid paramos of the Colombian Cordillera Oriental between c. 3425 and 4000 m. As stated before, these communities are in fact azonal but are discussed here for their large distribution on the humid side of the mountains. The area of zonal vegetation proper is proportionally smaller on the cloudy and wet side of the Cordillera. II .

Community of SwaZZenoch loa with Eryngium humile and Jensenia erythropus Fig , 19 (also Fig. 75) photo: Cleef 1978 , photo 165; Breure 1976 , Fig. 25

This type of zonal bamboo-bunchgrass paramo occurs usually with stem rosettes on sloping ground and on moderately to very steep slopes. Calamagrostis effusa or SwaZZenochloa tesselata each may cover up to about 70 %. species of Espeletia are e.g . E. grandiflora (div. var.), Vicariant E'. artnemariana, E. curialensis, E. cleefii, E. discoidea var. brevis and E. incana. The presence of Rhynchospora ruiziana, Eryngium humile, Gentiana sedifolia, Jensenia erythropus is differential against other communities. Scarce or absent are : Oreobolus obtusangu lus ssp . rubrovaginatus, Grammitis moniliformi~ Sphagnum spp ., Cladia aggregata, Eriocaulaceae, Cladonia andesita and Ar cytophyllum muticum. The humic black clayey soils are about I m thick. The upper peaty soillayer is moderately acid with a pH of 4 . 6 to 5.5 . The vegetation can easily be burned in the dry season. On the burnt sides there is a remarkable increase of herbaceous rosette species, e.g. Eryngium humile, Lysipomia sphagnophila ssp. minor var. minor, Rhizocephalum cando Uei, Casti_U eja. fissifolia. Hygrophytic and skiophytic elements in the bryophyte layer become less common. This type of bamboo-grassland is apparently common throughout the humid paramos of the Colombian Cordillera Oriental between 3450 and 3850 m. A major part of the Paramo de Sumapaz is covered with this kind of bamboo-bunchgrass vegetation with Espeletia stemrosettes, reaching up to 4000 m. 路

12.

Community of SwaZZenochloa with Rhynchospora paramorum/CastrateZZa piloseZZoides and Oreobolus obtusangulus ssp. rubrovaginatus Fig. 20 , JOe

This community is mostly found on the well-drained or driest places in the lo~e r bamboo paramos throughout the Colombian Cordillera Oriental between c. 327路0 and 3875 m. Generally Calamagrostis effusa dominates over Swallenochloa tesselata. Characteristic and frequent species are Hypericum st-r'ictum, Bartsia sp., Rhynchospora macrochaeta, Rhynchospora paramorum, Oreobolus obtusangulus ssp. rubro-vaginatus, Oritrophium perui;ianum, Vaccinium floribundum var. ramosissimum, Pernettya prostrata (mostly var. purpurea), Cladia aggregata and Halenia spp . Less common are Calamagrostis bogotensis, AzoreZZa cuatrecasasii, ArcytophyUum muticum and Paepalanthus andicola var. villosus. This vegetation type may be subdivided in I) slope vegetation, with CastrateZZa piloseZZoides, Rhacocarpus purpur ascens and Sisyrinchium pusiZZum, and 2) boggy stands, with Sphagnum spp. (e.g. S. compactum, S. sect.

Malacosphagnum) . Th e slope vegetation may be further subdivided in vegetation at intermediat e

altitudes (c. 3550 - 3875 m) with Castilleja integrifolia and Aragoa cupressina, and in vegetation at lower levels (3270-3320 m) with such characteristic species as Lysipomia muscoides ssp. simulans, Xyris spp., ana Paepalanthus pilosus and P. !odiculoides var. lodiculoides. The main bamboo cover here is larger than in higher parts. Vicariant associated species are e.g. Espeletia congestiflora, E. grandiflora, E. lopezii var. major and E. annemariana. Rhacocdrpus - SwaZZenochloa slope vegetation is found in humid paramos on brownish to black humic, thin (10-40 em) sandy to clayey soils, moderately acid (pH 4.7-4.8) in the top layer. Slopes are up to 30째. The bryophyte layer is well developed and may cover up to 75%. This kind of Swallenochloa slope vegetation is common in all lower bamboo paramos of the Colombian Cordillera Oriental. Its lowermost stands with Lysipomia muscoides and Paepalanthus pilosus have only been studied in the perhumid bamboo paramos near the Pefia de Arnical, NE of Lake Tota (Boyaca). The boggy vegetation with Sphagnum spp., Paepalanthus lodiculoides and Cladonia spp. is also found on slightly sloping ground. Castratella pi lose Uoides Xyris sp'p. and Rhacocarpus purpurascens are less common with a cover of less than 3%. The community is found on thicker, moderately acid (pH 4.6-5.3) humic sandy or sandy to clayey soil. The releves are from the lower humid paramos (3300-3380 m) N and NE of Lake Tota. 13.

Community of Swallenochloa with Oreobolus obtusangulus ssp. rubrovaginatus Fig. 21 (also Fig . 28, 69

70)

This zonal humid bamboo - bunchgrass paramo differs from the previous

Swallenochloa communities by the presence of Oreobolus obtusangulus ssp. rubrovaginatus in combination with the absence of Sphagnum spp., Castratella spp., Rhynchospora paramorum~ Xyris aeutifolia, Eryngium humile, Gentiana sedifolia and Jensenia erythropus. In this unit can be recognized the following types: a) Oreobolus - Swallenochloa paramo with Rhacocarpus purpurascens Oritrophium peruvianum and Eriocaulaceae (Paepalanthus karstenii, Eriocaulon mierocephalum). This kind of bamboo paramo vegetation is common throughout the study area between 3300 and 4150 m. It dominates especially bamboo-bunchgrass paramo (4000-4150 m). The humic black clayey soils are about 30 em thick or less. The pH of the moderately acid topsoil is 4.6-4.9 and the community is found on gentle as well as on steep slopes. b) Oreobolus - Swallenochloa - bamboo-dwarfshrub paramo with Hypericum laricifolium ssp. laricifolium and Blechnum loxense as common associated specie.s. This low shrubby bamboo vegetation is generally rich in species and is only locally noted in the lower p&ramos between 3300 and 3600 m.

B u n c h g r a s s

r a mo

This paramo grassland is in the Cordillera Oriental of Colombia dominated by tussocks or bunches of Calamagrostis effusa with stemrosettes of Espeletia or Espeletiopsis. Some species of the Espeletiinae are nearly restricted to the bunchgrass paramo; e.g. Espeletia barclayana, E. brachyaxiantha, E. jaramilloi; and Espeletiopsis corymbosa, E. guacharaco, E. muiska, E. colombiana. Species of Espeletiopsis are practically absent in the bamboo paramo. Only a few species of Bspeletia are common to both, the bunchgrass and the bamboo paramo where they occur in the same physiographic setting such as

Espeleti a congestiflora, or in different habitats such as E. grandiflora . Other species common throughout the bunchgrass paramo are Gongylanthus liebmannianus, Stephaniella paraphyllina, Gnaphalium antennarioides , Hypericum strictum, Castilleja integrifolia, Bartsia sp., Hieracium avilae, Hypochaeris sessiliflora, Vaccinium floribundum var . ramosis simum, Pernettya prostrata, Cladia aggregata, Cladonia isabellina, C. capitata, Siphula sp., Diploschistes sp . , Halenia sp ., Sisyrinchium pusillum, Polytrichum juniperinum, etc . Soils are 10 to 70 em thick and consist of dark-brownish to black humic (sandy) clay in the lower parts or of thin brownish coarse sand in the upper grass paramo路. The toplayer is moderately acid with a pH of about 4 . 8 (3 . 9 5 . 3). The zonal vegetation is found on moderately to very steep slopes . L o w e r

b u n c h g r a s s

p a r a m o

Bunchgrass vegetation with many species in the lowermost part of the grass paramo on the dr y side of the Colombian Cordillera Oriental belongs to this zone of the paramo vegetation . The communities of the lower bunchgrass paramo are mostly present on sloping to very steep parts . The toplayer of the brownish to black sandy an clayey soils is moderately acid . 14.

Lower Calamagrostis effusa bunchgrass paramo with Espeletiopsis Fig . 22 (also Fig . 78)

This type of tussock grassland is easily recognized by the presence of geographically vicariant species of Espele tiopsis (e.g . E. corymbosa, E. guacharaco, E. muiska) with their characteristic brittle , coriaceous leaves . Stemrosettes of this genus have not been found in other communities of the lower bunchgrass paramo . Bamboos are absent in this vegetation , but may be present in adjacent flat areas . This open grassland dominated by Calamagrostis ef fusa (65 - 95% cover) contains some scattered constituents of the dry dwarfshrub paramo : e . g. Arcytophyllum nitidum (I- IS% cover) , Brachyotum strigosum, Siphocampylus columnae, Bucquetia glutinosa and low Gaultheria speci e s with glandular hairs such as : G. cordifolia, G. hapalotricha, G. regia, G. rigida. Other 路 characteristic specie~ are Achyrocline lehmannii, Acaena cylindristachya, Geranium sibbaldioides, Luzula cf . racemosa, Polytrichum juniperinum, Lobelia tenera, Hypericum mexicanum, and H: caracasanum ssp . cardonae . The community is common on moderately to very steep slopes . The wellaerated so i ls consist of brownish-black sand or sandy clay and are 20-70 em thick . ~he pH of the toplayer is about 4 . 8 (4 . 5- 5 . 3) . This type of Espele t iopsis- bunchgrass paramo was mainly studied between 3500 and 3750 m (r~ng e 2935 - 3760 m ) in dry paramos surrounding the Sabana de Bogota (e . g . Neusa) and extending towards the Paramo de Guantiva. It may be common throughout the dry paramos of the Colombian Cordillera Oriental.

15.

Lower Calamagrostis effusa bunchgrass paramo with Espeletia, Oreobolus obtusangulus and Castratella Fig. 23 (also Fig. 51, 71, 75 and 78) photo: Cleef 1978, ·photo 164, 166 Gradstein et al. 1977, plate 2B

This open paramo bunchgrass vegetation or meadow is dominated either by

Calamagrostis effusa (occasionally Cortaderia sericantha) or by Cyperaceae , (Rhynchospora paramorum, Oreobolus obtusangulus ssp. rubrovaginatus). Characteristic are a number of sessile rosette and tufted species, which aye nearly absent in the previous corrnnunity: e.g. Castratella piloselloides , • C. rosea, Rhynchospora par~orUm, Oreobolus obtusangulus ssp. rubrovaginatus,

Oritrophiwn peruvianum, AzoreUa cuatrecasasii, Rhynchospora macrochaete, Gnaphaliwn antennar ioides and Altensteinia leucantha . Stem rosettes belong t o geographically vicariant species of Espeletia, e.g. E. congestiflora, E. barclayana, E. grandiflora. Arcytophyllwn nitidum has a low cover (I - 5%); Swallenochloa is virtually absent. The unit may be subdivided into: a) a Calamagrostis effusa dominated grassland in the dry paramos (3450 - 3750 m), and b) low cyperaceous meadows with few Calamagrostis bunches (cove r up to 35%) in atmospherically humid paramo s (3070-3700 m). Rhynchospora paramorum may cover up to 75% and Oreobolus obtusangulus ssp. rubrovaginatus up to about SO% of those meadows, which are floristically also different by the presence of Xyris acutifolia (or X. subulata) and of Tofieldia falcata, Rhacocarpus purpurascens, Sphagnum compactwn and Pilopogon laevis. This cyperaceous humid paramo meadow has ecologically an intermediate position between the preceeding type Calamagrostis effusa dominated paramo (!Sa) and the Swallenochloa - Calamagrosti s e ffusa vegetation (12) in the grass par amos. · These both types of the lower _bunchgrass pararno with Castratella are generally found on moderately steep slopes (8- 15°). Most of the soils are humic black sandy clay, 40 to 85 em thick. The pH of the toplayer is slightly lower than in the Espeletiopsis lower bunchgrass paramo, 4.5- 4.9 (range 4.0- 5.1). This zonal corrnnunity of lower bunchgrass pararno with Castratella spp. and/or Rhynchospora paramorwn was observe d in the entire study area, mainly between 3500 and 3750 m (range 3070 - 3760) both on the dry a!ld on the humid side of the Cordillera. It is nearly absent in the most arid paramos, e.g. the west side of the Sierra Nevada del Cocuy, where a lower grass paramo zone is not present. In view of the wide distribution of the characteristic species, the unit is likely to oc cur throughout the Colombian Cordillera Oriental. Castratella piloselloides is found up to 3800 m, Rhynchospora paramorum up to 3950 m. I believe, most releves of open bunchgrass-dominated lower pararno vegetation belong published by Lozano & Schnetter (1976) from the Paramo de Cruz Verde to this community. The same applies to such releves of the adjoining Paramo de Monserrate above Bogota, presented by Sturm (1978).

16.

Lower CaZamagrostis effusa bunchgrass paramo with OreoboZus obtusanguZus ssp. rubrovaginatus Fig. 24 ( a lso Fig. 50)

The open CaZamagrostis effusa dominated vegetation is characterized by tufts or low cushions of OreoboZus obtusanguZus , the cover of which is I- 10% (40%). Frequently associated species are Rhynchospora macrochaete, Oritrophium peruvianum, GentianeZZa corymbosa, Sisyrinchium pusiZZum, and CZadia aggregata . Rhynchospora paramorum is infrequent; SwaZZenochZoa and CastrateZZa are absent.

Two t ypes of vegetation can be r ecognized in this community. a) The first one is zonal and covers dry slopes (5 - 35°) be tween 3600 and 3900 m. In the humid grass paramos it is found adjacent to bamboo communities. Geographically vicari ant species of EspeZetia are: E. congZomerata, E. brachyaxiantha, E. discoidea var. brevis (trans gr.) , E. barcZayana,

E. grandifZora. The soils are 25 to 75 em thick and consist of silty da rkbrown to black clay. The pH of the humic top layer is about 4 .8. b) Th e second type is a more or less open CaZamagrostis effusa grassland with azonal tendencies (Fi g . 71). This vegetation is found on gently slopes (2 - . 6°) and is transitiona l towards Sphagnum bogs. It is marked by a number of additional more or less hygrophytic species, e.g. Carex pichinchensis,

BZechnum Zoxense, Xyris acutifoZia, Sphagnum compactum, S. cycZophyZZum, S. mageZZanicum, Kurzia verrucosa, Lepidozia sp., CZadonia subg. CZadina , SiphuZa sp., Rhacocarpus purpurascens . Cyperaceae and Sphagnum spp. may cover up to 35%. Both the subspecies rubrovaginatus and the ssp. obtusanguZus of OreoboZus are found, the latter often associated with low hummocks of VaZeriana stenophyZZa . EspeZetia chocontana was noticed only in this vegetation type. In addition EspeZetia grandifZora var., E. miradorensis and E. kiZZipii var. chisacana are recorded as vicarious species. Soils are humi c black clay, about 80 to more than 120 em thick. The pH of the peaty top soil l ayer is 4.4 to 5.5. This azonal peaty · bunch grass vegetation has been studied in dry paramos in the southern part of the Colombian Cordill e ra Oriental (Neusa to Sumapaz) between 3450 and 3700 m.

66 17.

Lower Calamagrostis effusa bunchgrass paramo with Espeletia argentea or

E. boyacensis Fig. 25 (also Fig. 70) This dry Calamagrostis effusa bunchgrass paramo is readily recognized by the almost sessile rosettes of both geographically vicarious species of Espeletia sect. Argentina Cuatr. (ined. ): E. argentea and E. boyacensis with numerous long and small, white to silvery leaves. The tussocks cover 30 to 90%. Characteristic species are Acaena cylindristachya, Geranium sibbaldioides~ Luzula cf. racemosa ~ Arcytophyllum muticum and Polytrichum juniperinum . Dwarfshrubs (e . g. Arcytophyllum nitidum~ Brachyotum strigosum) attain 25 - 30% cover in stands near the dwarfshrub paramo zone. Swallenochloa tesselata is near l y absent, just as other characteristic species as Castratella piloselloides ~ Rhynchospora paramorum~ Oreobolus obtusangulus ssp. rubrovaginatus and Oritrophium pervianum~ characteristic of other low~~ grass paramo communities in the Colombian Cordillera (see 3.1). The greate~t floristic affinity is with the Espeletiopsis - lower bunchgrass paramo vegetation (see 4.1), with many characteristic species in common. The Espeletia - Calamagrostis effusa paramo described here is mainly found on black humic sandy or silty c lay or on black sandy soil, 25 to 100 em thick. Th e we ll - aerated, frequentl y stony top soil has a pH of 4.1 to 4 .8 (5.2). The communit y may be found in flat areas, but is mainly present on moderately to very steep slop.es in the southern part of the Cordillera Oriental (Guantiva to Sumapaz), between 3600 and 3800 m (range 3450- 3865 m). The ''Es peletietum argentea- Calamagrosti effusum" ~ des cribed by Cuatrecasas (1934) from the Paramo de Gua~ca, is largely identical ~ith this community, its Espeletia grandiflora patches, however, to the CastrateZZa-bunchgrass par amo .

18.

Acaeno cy!indristachyae - Plantaginetum sericeae ass. nov. type rel. 568; table I. Fig. 26 (also Fig. JOd, 13, 18)

, Physi ognomy: The dry and open low herbaceous paramo vegetation is dominated by small ground ros e ttes (cover 20-80%) with white-silvery leaves. The dominant foliage has the characteristics of xe romorphy: the shiny small l eaves are cove red with a sericeous dense indumentum of appressed silvery hairs. Composition & syntaxonomy : Plantago sericea ssp. argyrophylla is a selective character species. Dr. K. Rahn (in prep.) recognized seven subspecies of Plantago ser1:cea , widely distributed in the tropical high Andes from northern Argentina and Chile to Colombia and Venezuela, with some representatives in the Mexican mount a ins. Acaena cylindristachya is a preferential character species. Common species are Stepham:eUa paraphyllina ~ Gongylanthus liebmannianus~ Siphula spp. (e .g . S . fastigiata)~ Polytrichum juniperinum~ Aciachne pulvinata~ Luzula cf . racemosa~ and crustose lichens of Diploschistes and/or Lecidea. Locally associated are Racomitrium lanuginosum on foggy crests~ Pilopogon laevis and Stereocaulon atlanticum in atmospherically humid habitats in the lower paramo, and the tiny Funaria lindigii . The average number of species is about 16 (12- 19 in 5 releves) . The new association has the greates t affinity with'路 the Aciachnetum pulvinatae (see 107) and with zonal Calamagrostis effusa - Espeletiinae communities with Acaena cylindristachya and Luzula racemosa (see 10, 12 & 14).

Table I .

Acaeno cyZindristachyae - PZantaginetwn sericeae ass. nov .

rel.nr. releve area m2 slope (degree) cover % grasses dicots soil pH top soil approx. number of species alt. m locality ~over % c & d taxa and companions c Plantago sericea ssp. argyrophyUa

Acaena cyZindristachya Aciachne puZvinata Luzu Za cf . racemosa Siphula sp. Lecidea/PipZoschistes GongyZanthus liebmannianus StephanieUa sp (p.) Po Zytrichwn juniperinwn Pernettya prostrata var. prostrata Oxalis sp. StereocauZon sp . (S. atlanticwn) CCl11Tpy lopus s p. Hypericwn car acasanwn ssp. car donae Agrostis trichodes CZadia aggregata Brywn sp. (fruct.) Agrostis breviculmis Agrostis haenkeana Racomitriwn crispuZwn/R. Zanuginoswn Castilleja sp. Leptodontiwn pungens PaepaZanthus karstenii LachemiZZa sp . Funaria Zindigii Cora pavonia Parmeliaceae

S64

S68

Alm Coc Pi Gua

102 x407A SS3x

14 3 72

9 3 81 s/g

IS 2 7S s/g

sfg

10 3 10

s S. l

2S I+ <I -<I+

4S <I

10 <I

I+ I+

S.3 19 17 IS 18 12 7 382S 3890 406S 3SOO 3880 342S Alm Alm Coc. Pi Gua Alm •

60 2

<I <I+ 10 S I 10 <I <I <.I+ <I

<.I+ <I

s 2

I? 1/~

10 <I <I <I+ <I

so <I 10 <I <I+

20 <I I

<I <I

<.I .-<::1

<I +

I+ 2

<I 2

70 <I

<I <I+ <I

s <I+ S <I <I

Hypericwn seZaginoides Bartramia sp. PiZopogon laevis Baeomyces imbricatus GentianeZZa corymbosa Aphanactus piloselZoides CZadonia boZiviana CZadonia andesita Carex aff. conferto~·spicata Thamno Zia verm·icu Zaris Hypochoeris sessiUfZora Danthonia secundiflora ~ocalities:

IS9

Almorzadero, El Tutal Cocuy , Lagunillas Pisva , El Cadillal NW of Belen, Laguna Larga

<I 3S <I+ <I <I <I+ <J

-<I

68 Synecology: This groundrosette community is present on level or in places sloping up to about 30째. The shallow gravelly brown cl ayey soil is 5 - 10 em thick. pH of the toplayer is 5.1 and 5.3 in sandstone areas; pH data from the calcareous bedrock are not available. The wide distribution of this community on the dry side of the Paramo del Almorzadero may be attributed to intensive grazing of cattle in combination with a shallow soil, which is dry due to high porosity of the calcare ous bedrock . The natural habitats of this xerophytic community are most probably places n e ar crests and ridges with only a thin topsoil. Distribution: The Acaeno - Plantagine tum sericeae is optimally develop e d on the dry southern slopes of the Paramo del Almorzadero between 3700 and 3900 m on calcareous rock. This zonal dicot association is found in the northe rn paramos of the study area and has been recorded in the paramos of Guantiva , Pisva, Cocuy and Almorzadero between 3.425 and 4070 m. According to Dr . K. Rahn (in prep.) the subspeci e s argyrophylla of Plan tago sericea occurs as far a &Cthe paramos of the Sierra Nevada de Merida (Fig. 10d). It is unknown whether or not this association is also present in the Venezuel an Andes. U p p e r

b u n c h g r a s s

p a r a mo

The hi ghest located bunchgrass paramos extend from about 3900-4000 m up to the lowe r limit of the superparamo (4250- 4400 m). Spaced bunches of Calamagrostis effusa with up to 50 % cove r make up th e main vege t a tion, and are usually associated wi th stemros e ttes of th e Esp e l e tiinae, e . g . Espeletiopsis c olombi ana ~ E. guachar aco , E. san tande rensis ~ and Espeletia lopezii var. alticola , E. cleefii and E. azucarina . Common species in the gravelly spaces between the tussocks are: Stephaniel l a paraphyllina~ Gongylanthus liebmannianus, LuzuZa cf. racemos a, Polytrichum juniper inum, Per nettya pr ostr ata var. pr os trata, Cladia aggregata~ Cor a pavonia ~ Bar tsia

spp.~ Castilleja spp.~ Hypochoeris sessiZi fl ora~ Siphula sp. ~ Agros t is boyacensis, Campy lopus spp.~ Grammitis moniliformis and Zygodon pi chinchensi s . Dwarfshrubs of Lachemil la polylepis , Di plostephum colombianum and Loricaria complanata are locally common . Open gravelly stretches may contain superparamo species, e.g . Senecio cocuyanu s~ S . adglaci alis , S . cle e fi i ~ Lycopodi um crassum ~ Dr aba litamo , Loricaria complanata. Frost heaving acts almost eve ry night in

open barre n places . In contrast to the lower grassparamo scarced or absent species are Gentiane lla co rymbos a ~ Azor ella cuatr ecas asii~ Calamagr os ti s

Geranium sibbaldioides, Rhynchospora paramorum and Arcytophy ZZwn muticum .

boyacensi s ~

macrochaeta ~

Rhynchospora

Upper bunchgrass paramo is we ll developed in th e Sierra Nevada del Cocuy (3900- 4500 m) and has been studied in the summit are a s (4000-4 200 m) of the Paramo de Guantiva and the Paramo del Almorzadero. The dry cre sts and watershed areas at 4000 m in the Paramo de Sumapaz carry an open sward of a similar nature. It s e ems appropriate to include the upper bunchgrass fringe on the clouded side of the mountains, although some floristic differences may be noticed. 19.

Upo e r Calamagrostis effusa bunchgrass paramo with EspeZetiopsi s Fig. 27 (also Fig. 34)

This bunchgrass community has its greatest distribution on the dry side of the Sierr a Nevada del Cocuy , whe re Jame s onia bogotensis is characteristic. The lowermost stands between 3900 and 4 100 rn have a number of species in common

69 with the lower bunchgrass paramo, e.g. Acaena cylindristachya, Gnaphalium antennarioides, Diploschistes sp ., Lecidea sp., Castillleja fissifolia, C. integrifolia, Baccharis tricuneata, Carex sp . (C. pygmaea type), Geranium subnudicaule or (G. multiceps), Lycopodium spurium, Arcytophyllum nitidum and occasionally Plantago sericea ssp . argyrophylla. This open grassland is locally found up to 4500 min nunatak-like places, which became free of snow and ice many thousands of years ago and were not covered by ice during the recent Neoglacial (Vander Hammen et al., 1981) . Calamagrostis recta, another major bunchgrass species, is characteristic, and may be (co)dominant with Calamagrostis effusa. Calamagrostis recta is the most common bunchgrass in the paramos of the Colombian Cordillera Central (Cleef et al., in press) and in the Ecuadorian paramos . This species is rare in the study area and could only be collected in the upper reaches of the Paramo de Guantiva and on the nunatak-like divide between the high valley of Lagunillas and the Paramo C6ncavo on the SW-side of the Sierra Nevada del Cocuy. The grasscover on such nunatak-like high crests is generally limited and does not exceed 40% . Espeletia lopezii var . alticola and Poa cf . pauciflora (5661) are frequently associated . The proportion of the superparamo taxa is conspicuously high, as may be expected at this altitude . Geographically vicariating species of Espeletiopsis are E. santanderensis in the Paramo del Almorzadero arid Santurban, E. guacharaco in the Paramo de la Rusia and Guantiva and E. colombiana in the Sierra Nevada del Cocuy. Soils under the Espeletiopsis - Calamagrostis effusa vegetation in the Sierra Nevada del Cocuy are thin (to 20 ern), and they consist mainly of very dark gray or brown , coarse sand with a pH of 5.1 (range 4.9- 5.3). The upper bunchgrass paramo is covering valley slopes as steep as 40째 and moraines. According to van der Hammen et al. (1981) most of these moraines (in the Sierra Nevada del Cocuy) belong to Drift 5, and were formed during the Bocatoma stade between 12,000 and 7 . 500 B. P . 20.

Upper Calamagrostis effusa bunchgrass paramo with Espeletia Fig . 28

This open bunchgrass community is common on the clouded and misty side of the mountains, where it fringes the upper limit of the zonal paramo . Floristically , this community differs from that on the opposite and dry side of the Cordillera by the presence of species of Espeletia, Cerastium, Halenia and Poa. Other hygrophytic species, which are absent in the dry and highly located bunchgrass paramos, gradually appear towards the humid side, e.g. Rhacocarpus purpurascens, Carex pichinchensis, Oreobolus obtusangulus ssp. rubrovaginatus, and Elaphoglossum spp . The cover of AnastrophyUum leuco ~tomum becomes larger , whereas .~hat of the xerophytic Stephaniella paraphyllina diminishes in the bottom layer. Geographically vicariating Espeletia species are e.g. E. conglomerata (Almorzadero), E. cleefii (Cocuy) , E. azucarina (Guantiva) and E. grandiflora (Sumapaz). This open grassland gradually passes into bamboo-bunchgrass vegetation with the appearance of the first clumps of dwarfed Swallenochloa tesseleta. Locally, along the upper bunchgrass limit (4260-4320 m), tussocks of Lorenzochloa erectifolia replace Calamagrostis effusa on fine sandy soils. Soils, covered with the upper Espeletia - Calamagrostis effusa community , consist of brownish to black coarse sand with a pH of about 4 . 8. In the upper Lorenzochloa tussock stands, pH values of 5.4 and 5 . 5 have been measured, however , and this agrees better with the values in the lower superpararno.

Calamagrostis recta vegetation on high nunatak-like watershed areas on the opposite dry side has species of Espeletia, Poa, Halenia, and Cerastium in common with the Espeletia-bunchgrass paramo. Frequent fog may be one of the causes of this floristic similarity between the two Espeletia-bunchgrass communities. THE SUPERPARAMO The superparamo is the highest vegetation belt in the tropical northern Andes, located between the upper bunchgrass line and the lower limit of the nival belt. Ice-free places (nunataks), with vegetation in the nival belt belong to the upper superparamo. Due to the high elevation and the tropical diurnal climate, nightfrosts occur daily throughout the year. As a result, the plant cover is scanty, and sessile rosette plants and dwarfshrub are most prominent in the zonal vegetation. Acrocarpous Titosses are conspicuous, but they are replaced by liverworts and pleurocarpous mosses in the zonal superparamo locate d in the upper condensation zone (Gradstein et al. 1977) . Soils are generally stony and thin without a distinct profile. The brownish or grayish toplayer is less acid than in the grass paramo (pH 5.1-5.6). At present, s uperparamos are isolated in the highest parts of the Colombian Cordillera Oriental. During certain intervals in times of Pleistocene glaciation they were larger and they may have reached down to about 3500-3000 m (e.g. on moraines). During the coldest periods the superparamo areas of the Sumapaz and Cocuy were much closer to each other but never adjoining; thos e of the Cocuy and Almorzadero, however, may have been united (Vander Hammen et al. 1981; Vander Hammen & Cleef, in press). A number of vascular endemics are characteristic for the superparamo. Senecio niveo-aureus is endemic for the Colombian Cordillera Or-iental and is replaced by the vicariating closely related Senecio latiflorus, endemic in the high paramos of the Colombian Cordillera Central. Endemism is best examplified by species belonging to different sections of Senecio occuring at high altitudes, and species of Draba. Several endemic Senecio species are restricted to one summit or one range; e.g. Senecio santanderensis, is only known from the Paramo del Almorzadero and the Paramo de Santurban, and its close ally S. cocuyanus to the Sierra Nevada del Cocuy. According to the theoretical model developed by He Arthur & Wilson (1967) for oceanic islands and appliecl by Vuilleumier (1979) to the paramo and puna avifauna, the highest rate of speciation for the paramos of the Colombian Cordillera Oriental is to be expected in the Sierra Nevada del Cocuy. This Sierra contains the highest range of the Cordillera Oriental and the largest recent extension of the superparamo zone. Most of the endemic species of Senecio are actually found here, and they include the herbaceous Senecio cocuyanus, S. adglacialis, S. supremus, and S. pasqui-andinus and the shrubby species S. guicanensis and S. cleefii. Draba litamo and D. hammenii are endemic also, just as some new , undescribed species of Draba (8882, 8883, 8989, 8991, 10182) . This region has at least one of these, a cushion species (8990 , 9014), in common with the superparamo of the Paramo del Almorzadero. The superparamo of the Nevada de Sumapaz (4250 m) probably contains at least one endemic large rosette species of Draba (1116, 7668) , apparently not yet described. The limited size (less than 1 km2) and the comparatively low altitude (4250-4300 m) of the Nevada de Sumapaz may account for the smaller number of endemic vascular species. Senecio canescens, S. niveo-aureus, S. forrnos.u s and S. flos-fragrans are species common to this region and the superparamo of the Sierra Nevada del Cocuy. Senecio vernicosus and S. summus

of the Sumapaz are the only species in common with the high paramos of the Colombian Cordillera Central; the latter species is also present in Ecuadorian paramos. The large number of species with their main distribution in Central Colombian and Ecuadorian paramos is noteworthy in the high Paramo de Sumapaz. The following species belong to this southern paramo flora:

Senecio repens, S. vernicosus, S . summus, Ourisia muscosa, Werneria humilis, Valeriana plantaginea, Diplostephium rupestris, Baccharis caespitosa var. alpina, Geranium multipartitum, Cerastium imbricatum, Rumex tolimensis, Potamogeton asplundii .. A few of them are present also in the Sierra Nevada del Cocuy, e.g. Valeriana plantaginea, Ourisia muscosa and Cerastium imbricatum. On the other hand, the superparamo of the Sierra Nevada del Cocuy have also a few species in common with the Colom&ian Cordillera Central, which have not ye t been recorded from the Paramo de Sumap az, e.g. Distichia muscoides, Floscaldasia hypsophila, Werneria crassa. Proportions of various phytogeographi c elements in the vascul ar flor as of the Cocuy and Sumapaz superparamos are reported in Vander Hammen & GleeÂŁ (in press). In the zonal superparamo vegetation the absence can be noticed of

Calamagrostis effusa tussocks and other associated up~er grass paramo species as Acaena cylindristachya, Achyrocline lehmannii, Gnaphalium antennarioides, Castilleja fissifolia, Siphula spp. and Hieracium avilae . White and ye llow flowering sess il e rosettes with large penroots of Hypochoeris sessiliflora s.l. are common to all superparamos. Species of Senecio , Draba, Bartsia, Lucilia, Luzula cÂŁ. racemosa and Racomitrium crispulum are frequent also. The last speci es, however, has the highest cover in the humid superparamo, especially in the upper condensation zone where it is a ssociated with many characteristic bryophytes, e. g. Bartramia angustifolia, Breutelia in.tegrifolia and B.

lorentzii, Rhacocarpus purpurascens , H. acanthelius , Herbertus subdentatus, Metzgeria metaensis, Plagiochila dependula, Radula sonsonensis and Riccardia squarrosa .. The moss Zygodon pichinchensis attains its highest cover near the boundary between the superparamo and grass paramo, especially in the Si err a Nevada del Cocuy. Pernettya prostrata is most common in the superparamos on the dry side of the mountains, whereas Senecio niveo- aureus, Erigeron chionophilus and Valeriana plantaginea are ch:1racteristic for the humid paramos on the opposiste cloudy side. Espeletiinae may penetrate the lowermost part of the superparamo on the humid side of the mountains and may be found as high as about 4650 m on nunatak-like divides , e.g. the C6ncavo-Boca toma divide in the Sierra Nevado del Cocuy. Partly edaphically determined pionee r vegetation, similar to zonal superparamo vegetation, occurs on young (Neoglacial) moraines, down to sev eral hundreds of me ters below the climatic zonal boundary of upper grass paramo and lower superparamo. Superparamo vegetation in the Colombian Cordillera Oriental has b een studied on I) the Nevado de Sumapaz (4100-4250 m) and th'e adjacent hi gh peaks of Sitiales (4040 m) and S. Mateo (estimat e d at 4100 m) in the Par amo de Sumapaz; 2) the Pan de Azucar (4220-4270 m) and Morro Verde, the highest peaks of the Paramo de Guantiva near Belen (Boyaca ); 3) the southern part of th e Sierra Nevada del Cocuy ÂŤ4250) 4400-4800 m) and 4) the Paramo del Almorzadero (4250- 4375 m). Not studied was the superparamo vegetation on the Morro Nevado (c . 4300 m) in the Paramo Romeral about 20 km W of Pamplona , and on the highest ridges of the Paramo de Santurban (c . 4100 m), about 3 km SW of Vetas (Santander- Santander de Norte). According to Dr. J. Cuatrecasas (in litt.) the last summit areas are heavily grazed and dry.

For comparison releves were made in the superparamo of the Colombian Cordillera Central in the Parque Los Nevados (Cleef et al . , in press), on the volcano Purace, and ln the Paramo de Piedras Blancas, Sierra Nevada de Merida, Venezuela .

L o w e r

s u p e r p

r a m o

Most releves were made in the lower superparamos, which reach up to 4500 m. The climatologically dry and the humid zonal lower superparamos are floristically basically different from each other , and they are found on all summit areas with superparamo vegetation mentioned before. Vegetation of Luzula racemosa and Pernettya prostrata is characteristic for the moraines on the dry side of the Cordillera, whereas communities with Agrostis breviculmis, Senecio niveo- aureus, Erigeron chionophilus and Valeriana plantaginea are found on gravelly screes and on outcrops in the superparamo on the opposite humid side . Calcareous rocks were locally present in all investigated superparamos. In general the humid lowermost superparamos support a more luxuriant vegetation which is richer in species. The bryophyte layer is well developed and has a larger cover than on the dry side of the Cordillera, where bryophytes are scarce or absent .

21 .

Loricarietum complanatae ass . nov. type: rel . 468; table 2 . Fig . 28, 29, 30.

Physiognomy: The community typically is a high-altitude paramo d>varfshrub vegetation of 3 layers : I) an open dwarfshrub layer consisting of compositae of about 1-1 . 5 m high (cover 30-60%); 2) a herbaceous layer up to 35 em high (20-25%) ; 3) a poor open or well-developed nearly closed bryophytic ground-layer . Xeromorphic leaves are common . Thus, the most prominent species (Loricaria complanata, Jamesonia goudotii, Lachemilla nivalis) have a more or less imbricate leptophyllous foliage, often with indumentum or hairs of another nature . The coriaceous leaves of the shrubs are revolute and brownish . Composition & syntaxonomy : Character species are Loricaria complanata (exclusive), and Jamesonia goudotii and Lachemilla nivalis (both preferential). Other common taxa are Hypochoeris sessiliflora, Bartsia spp ., Oritrophium peruvianum, Cladia aggregata, Cladonia subg. Cenomyce and Campylopus pittieri, etc . The number of taxa is about 25 in the driest paramos (rel. 460) and is about twice as high in the wettest paramos (rel . 270) . Loricaria, a peculiar woody composite genus, is found in the high tropical Andes from northern Bolivia to Colombia (Cuatrecasas 1954). All three sections of the genus are found in southern Peru . Loricaria complanata (sect . Thuyopsis) is known from northern Ecuador, the Colombian Cordillera Oriental and Occidental and the Sierra Nevada de S. Marta. Its subspecies occidentalis Cuatr . is present only in the southern part of the Cordillera Occidental (3500-3700 m) . Jamesonia goudotii and Lachemilla nivalis are widely distributed from southern Peru to northern Colombia (Tryon 1962; E.G . B. Kieft , pers. comm.). At the generic level, the most prominent vascular taxa of this association belong to the neotropical Andean element.

73 Table 2.

Loricarietum complanatae ass . nov.

releve nr. releve area m2 slope (degree) cover % erect dwarfshrub prostrata dwarfshrub grasses (bamboos) mosses liverworts soil pH top soil approximate number of species alt. m locality cover % c & d and other taxa

Loricarietum complanatae Loricaria complanata Jamesonia gou.d otii Lachemilla nivalis d Oritrophium peruvianum Grammitis moniliformis Bartsia sp(p) . - greenish fl. (reddish fl.) Cladia aggregata Hypochoeris sessiliflora (yellow ray fl.) Hypericum lancioides Oropogon loxensis Cladonia subg . Cenomyce Jamesoniella rubricaulis Zygodon pichinchensis Anastrophyllum leucostomum Stereocaulon tomentosum Stereocaulon sp . Agrostis cf.haenkeana Peltigera sp(p . ) Cora pavonia d & o taxa pernettyetosum prostratae d Pernettya prostrata var. prostrata d Calamagrostis effusa Campylopus pittieri Carex pichinchensis Senecio vaccinioides Lycopodium crassum Senecio cocuuanus Sisyrinchium" trinerve Elaphoglossum mathez,)sii Acaena cylindristachya Thamnolia vermicularis Puya trianae Paepalanthus lodiculoides var. floccosus Halenia nivalis Diplostephium rhomboidale Diploschistes sp . /Lecidea sp. Gentianella corymbosa Lophonia incisa c c c

460 20 15 55 10 2 18 1 g

412 12

20 30

331 20 10 25 70

270

468

20 5

65 35

65 3 g

5.2 5.2 20 14 18 46 19 4380 4220 4330 4015 4200 Coc Gua Coc Sum Coc 0

<I +

I+

5 3 10

<I <I+ <I+

<I <I <I <I

-<:I

<I <I I

<I+ <I+

<T <I+

<I+ 2

10 I 2

.q 3

70 20 5 IS ~I

<::I

<I <I <I <I

I+ <I+ <I

d & o taxa racomitrietosum d

(460)

Racomitrium crispulum

d Rhacocarpus purpurascens

Valeriana plantaginea Riccardia sp. (R . walUsii) d Campylopus richardii d Siplzula spp . Campylopus sp. Swallenoclzloa cf. tesselata Anastrophyllum nigrescens Leptodontium wallisii Breutelia allionii B1â&#x20AC;˘eute lia chrysea Herbertus subdentatus Campylopus sp . (7744) Werneria humilis var. angustifolia Aciachne pulvinata Vaccinium floribundum var . ramosissimum Sphaerophorus melanocarpus Syzygiella sp. Radula sonsonensis Jensenia florsclztitzii (type sp . ) Adelanthus lindenbergianus Isotaclzis multiceps Cephalozia dussii Gymnomitrion atrofi lum (type sp.) Stephaniella sp. Lepidozia macrocolea Bartramia sp. (7753) Physcomitrium sp. (7742) Leptolejeunea sp . Cladonia subg. Cenomyce Lycopodium cf. rufescens (7735) Rhizocevhalum candollei Calamag'"rostis cf. coarctata Carex cf. pygmaea Carex aff. conferto-spicata d d

Locality :

Coc

Gua : Sum :

(270)

(468)

1 45 <1

25 30 2

< 1+

1 1+

10 10 25 8 5 3 5 3 2

<1 1

<.1 <1 1+

1 <: 1 <1 ' <1 <1 1 1+

<-1 1 <1 <1 <.1 <1

Cocuy : Paramo C6ncavo (Boyaca) (rel. 331A, 460) Patio Bolos (Arauca) (rel. 468) Guantiva: Pan de Azucar Nevado de Sumapaz

Syntaxonomically the association is well defined by its exclusive character-species Loricaria complanata that also determines its low shrubby aspect; it is closely related to the Lachemilla nivalis vegetation (see 28a) and to the Valeriana plantaginea- Racomitrium superparamo community (see 27) . The present description is made on the basis of the conditions in the Colombian Cordillera Oriental, where the subspecies complanata occurs. The association is subdivided into two gubassociations, which reflect different conditions of humidity (21a and 21 ).

Synecology: The new described association prefers well-drained stony thin soil near or on outcrops of bedrock, usually along the upper boundary of the bunchgrass zone proper with the superparamo. Parent rock may be sandstone, quartzite or limestone. A distinct increase in the number of woody species at this height is noteworthy, and may be attributed to special conditions in these places. They must have been covered with ice about 400 years ago during the Corralitos stade (Vander Hammen et al. 1981). The habitat of the Loricarietum compJ anatae on terminal moraines and outcrops was probably icefree at that time (the Neoglacial or Little Ice Age). It is supposed that present thermal conditions would allow for the development of a zonal upper bunchgrass paramo Edaphic factors, immature soils and rockiness, however, seem to prevent this. The thin soils cosist of brownish or grayish clay or sand, and they are moderately to weakly acid (pH 5.0-5.7) according to elevation. The area slopes up to zoo or more. 0oricaria complanata has often been observed in lower places, in superparamolike habitats (bare soil) along swiftrunning rivulets and in crevices of roche-moutonnee. Distribution: The Loricarietum complanatae is present throughout the high paramos of the Colombian Cordillera Oriental from 4000 (3800) to 4400 m. Cuatrecasas (1954) reported Loricaria complanata also from the paramos of the Cordillera Occidental, the Sierra Nevada de S. Marta and northern Ecuador; the Loricarietum complanata is supposed to be present here, but in the Venezuelan Andes it is virtually absent. 21a.

Subass. pernettyetosum prostratae subass. nov. (prov.) type: rel. 460; table 2. Fig. 30

Physiognomy: The physiognomy is similair to that of the association. The presence of a strongly reduced bryophyte layer (1-20% cover) accounts for the main physiognomical difference with the racomitrietosum (21b). Composition & syntaxonomy: Differential against the racomitrietosum are e.g. Calamagrostis effusa, Pernettya prostrata var. prostrata, Senecio vaccinioides, Lycopodium crassum, Diploschistes sp. These differential species also noticed though less frequent and with reduced cover - in the zonal lower superparamo on the cloudy side of the mountains. Presence of Pernettya prostrata and Calamagrostis effusa with a considerably cover in combination with the absence of hygrophytic bryophytes and vascular plants are the differential characters of this subassociation. The number of species is generally lower than in the racomitrietosum. Synecology: The perne ttye tosum fringes the upper bunchgrass paramo and is adjacent to zonal superparamo communities on the dry side of the mountains. The associated species are distinctly less hygrophytic than in the

racomitrietosum . Distribution: This subassociation is found in the Colombian Cordillera Oriental, on the dry side of the mountains from 4200 to 4400 m. 2 1b.

Subass. racomitrietosum crispuli subass. nov. (prov.) type: rel. 270; table 2. Fig. 29 (also Fig. 28)

Physiognomy: The physiognomy is similar to that of the association, but in addition there is a nearly closed bryophyte layer of 3-10 em thickness.

Composition & syntaxonomy: This syntaxon is rich in hygrophytic species, mainly bryophy tes, e.g. Racomitrium crispuZum, Rhacocarpus purpurascens, BreuteZia spp., Lepidozia macrocoZea, Campylopus richardii, Herbertus subdentatus, AnastrophyZZum spp., Jensenia florschUtzii , JamesonieZZa

rubricau Zis, Ade Zan thus Zindenbergianus, Riccardia wa U isi i , Gymnomi t r ion atrofi lum, RaduZa sonsonensis. The l a st three liverwort species are only known

from the upp er condensation belt in the Colombian Andes (J. Meenks, comm.pers., Vana 1976, Jans 1979). Oropogon Zoxensis, SiphuZa spp., and Sphaerophorus meZanocarpus are associated lichens, flourishing on damp soil or litter. VaZeriana pZantaginea, Lycopodium cf. rufescens and Werneria humiZis var. augustifolia (the latter only in the Paramo de Sumap az ) are, as most of the mentioned species, characteristic for and restricted to the upper condensation zone. Most hygrophy tic species mentioned above are differential against the pernettyetosum . More releves are required to decide 1vhether the pres ent rank is at subassociation or at the association level. Synecology : Thi s as.sociation was only found on soils d erived from calcareous rock. Bamboos are generally absent in the racomitrietosum, but on the Nevada de Sumapaz, where the lower limit of the superparamo is locat ed between 4000 and 4100 m, the racomitrietosum is just reached by the uppermost thickets of SwaZZenochZoa. Rhacocarpus purpur ascens is predominant in stands on a soaking-wet soil; Racomitr ium crispulum is common in less humid environment. SiZviZagus forages on sedges, Hypochoeris sessiliflora, and small grasses ~n rel. 270. Distribution: The racomitrietosum cr ispuZi is characteristic for the zonal lowermost humid~sup e rparamo vege tation in the upper condensat ion zone from 4000 to 4250 m on th e humid side of the Cordillera Oriental of Colombia.

22 .

Shrub of Senecio vaccinioides and DipZostephium r homboidaZe Fig. 30

These shrubs of Compo s itae were only noticed on t e rmina l moraines a long the grass pa r amo and supe rparamo in the Paramo C6ncavo , Si erra Nevada del Co cuy (dry s id e ) from 4300 to 4400 m. The Senecio vaccinioides shrub or the dwarfed trees of Diploste1)hium rhomhoidale are 2.00-2 .5 (4) m hi gh and cover about 75 %. Other characteristic and common associ a t ed species are Esveletia lopezii fma . alticoZa, Senecio andicoZa, LachemilZa tanacetifolia, Jamesonia

goudotii , LuzuZa racemosa, Senecio formosus, Zygodon pichinchensis, Bryum capillare, CampyZopus jugorum and Lophozia incisa . Most of these have not been found in th e zonal Senecio vaccinioides s ubparamo shrub (see 2). However , the two shrubby communities a re physiognomi ca lly and floristically similar, as spec ies Senecio vaccinioides, LachemiZZa cf. hispiduZa, Aciachne pulvinata,

Pernettya prostrata, Cerastium subspicatum, Agrostis boyacensis, Thuidium peruvianum, Tortula andicoZa, Polytr ichum juniperinum . In an undisturbed stand at 4400 m a thi ck laye r of the acrocarpous moss Zygodon pichinchensis is common on boulders and covers branches and thrunks.

Cetrariastrum dubitans and C. equadoriense ar e epiphytic lichens restrict ed to shrubby Compositae (Loricaria, Senecio, Diplostephium)o r Polylepis dwarf forest vegetation (Sipman 1980). The shallow soi ls are clayey to silty and a single -pH of 5 .0 was measured in th e 10 em thick blackish toplaye r .

23.

Community of Pernettya prostrata and Luzula racemosa Fig. 31 (also Fig. 28 , 30, 33, 35, 54, and 55) photo: Grads tein et al. 1977 , plate 2C; Gonzalez et al. 1965 , photo 5; Vander Hammen et al. 1981 , fig . 7 & 9 .

This unit was only studied on young moraines and mora~n~ c sediments in the Paramo C6ncavo and in the high Bo catoma valley on the dry west ern slope of the Sierra Nevada del Cocuy between 4250 an 4500 m. According to Van der Hammen et al. (1981) these moraines belong to the most recent drift, which became icefree after the Corralitos of th e "Little Ice Age", which may have lasted from 1500-1850 A.D . This means that this superparamo community and the upper bunchgrass paramo in that area are only slightly more than a century in the ir pr esent-day pos~t~on . The upper bunch grass - sward apparently was r epl aced by Luzula - Pernettya superparamo vegetation during the Corra litos stade. Fresh Drift 6 sediments are still being uncovered by the r eceed ing icecap , as demonstrated by photographs of the Paramo C6ncavo (Van der Hammen et al., 1981). Characteristic for the low superparamo on moraines is the abundance and high cover of Luzula cf. racemosa (up to 10%) and the dwarf shrub Pernettya prostrata var. prostrata (up to 15%) . Lycopodium crassum and poor specimens of Grammitis moniliformis, Cora pavonia and Campylopus cf. chrismarii var. suboblongus are common. Pa t ches with many Pernettya prostrata are found on the lowermost moraine s of the superparamo. The s tony soil is about 20-30 em thi ck; and consists of coarse sandy material, varying from brownish to gray and li ghtgray colors in the hi ghe st pl aces. The pH of the toplayer is 5 . 2 (5.1-6.1). Young moraines in the headwat e rs of the El Play6n river (between Lake La Plaza and Patio Bolos) on the opposit e c loudy side of the Si e rra are covered with a similar vegetation . 24.

Community of Espeletiinae with Geranium sibbaldioides Fi g. 28

Dens e populations of Espeletiopsis colombiana or Espeletia cleefii are locally found in the humid lower superparamo of the Sierra Nevada de l Cocuy ne ar Patio Bolos (4250-4300 m). Geranium sibbaldioides (cove r 5-8%), Bartsia 路sp., Gnaphalium antennarioides, Castilleja fissifolia ssp. pygmaea, Hypericum

selaginoides, Aphanactus ligulata, Erigeron ecuadoriensis, Cerastium subspicatum and Agrostis breviculmis are conspicuous and commonly associated species. This stemrosette vegetation is floristi ca lly int ermediate between the Senecio niveo-aureus gravelly scree community (26), the AcauUmalva - Agrostis breviculmis meadow (25) and the Espeletia upper bunchgLass paramo (20). The pH of the gravelly soils, which show a high degree of solifluction, is about 5 . 0. Gravel deposits at the base of steep slopes, lower t emperatures and frost action prevent Espeletia cleefii to reach higher loc a tions . The same is observed in the much drier Paramo de Piedras Blancas in Venezuela. Espe letiinae reach up to about 4600 m. Monasterio (1979) described diff er ent superparamo communities for this area, dominated e.g. b y I) Espeletia lutescens (Cuatr . & Arist) Cuatr. and Coespeletia timotensis (Cuatr.) Cuatr .; 2) Espeletia moritziana (Sch. Bip. ex Wedd.) Cuatr., and 3) Coespeletia spicata (Sch. Bip. ex Wedd.) Cuatr .

25.

Community of Agrostis breviculmis with Acaulimalva purdiei Fi g. 32 & 58

Characteristi c patches of c los ed, s hort meadow-like vegetation are found on stabilized screes (surrounded by communities 26 and 27) in the lower part of the superparamo. Small , low, tufted Agrostis breviculmis is prominent and covers 20 to 60%. Sessil e rosett es of Hypochoeris sessiliflor a, Acaulima lva pur diei and Calandrinia acaulis, firml y rooted in the gravelly soil, are characteristic and may cover up to 25%. Other common species are Oreomyrrhis andicola, Luzula cf. r acemosa, Lachemilla pinnata, Aongstroemia julacea and Gongylanthus sp. (9043a) and species of Aphanactus and Halenia. The sandy-gr avelly soil is not thicker th an 10 em and the pH of the top soil layer is es timated at 5.3. Frost heaving and deposition of grave l are the main factors that determine the size, pattern and cover of the stands. Thi s community has been studied on the Arauca slope of the Sierra Nevada del Cocuy (4250-4350 m) and in the summit area of the Paramo del Almorzadero (4100-4300 m) . A similar community was also observed in the Paramo d e Piedras Blancas at 4280 min the Venezuelan Andes. 26.

Community of Senecio niveo- aureus Fig. 32 & 58 (also Fig . 28) photo: Cle e f 1978 , photo 172

Thi s high Andean community of whitish large rosettes with silvery indumented leaves is found on unstable gravelly screes, which are common in the humid superparamo with high frost action. Daily the grave l is moving by free z ing and thawing of the wet brownish clayey matrix. Soils are weakly acid (pH 5.4-5.8). In stands with giant Lupinus alopecuroides, a pH of 6 . 7 was measured in the topsoil layer . Senecio niveo- aureus is the most characteristic rosette species, covering to 15%. Other common and characteristic species are Hypochoeris sessiliflora, Luzula c f. racemosa, Lachemilla tanacetifoli a, Aongstroemia julacea, Zygodon pichinchensis, Toi>tula andicola, Bryum argenteum and Leprocaulon albicans. Pioneer communities with a few rosettes of Senecio niveo- aureus are found on mod erately steep (12-20째) and extremely unstable, gravelly slopes. Patches of Senecio cocuyensis occur near outcrops of bedro ck. On less sloping and mo re stable screes the vegetation cover is higher with more associated species as Lupinus alopecuroides, Arenaria sp., Senecio formosus, Oreomyrrhis

andicola, Erigeron ecuadoriensis, Erigeron chionophilus, Cerastium subspicatum, C. imbricatum and Lucilia spp. (8956, 8979) . Frost action almost prevents seedling establishment in this habitat. Host companion species grow ne ar the rosettes of Senecio niveo-aureus in more stable soil. Unattached mosses and lichens are common and adapted to thes e "mobilideserta" (Troll 1944) or areas of a ctive solifluction, which are also known from other regions with an extremely cold and humid climate. Hedberg (1964) mentioned similar cryptogami c plantgrowth for the Afro~alpine zone and r e fer e d to relevant literature. Errant cryptogamic species in the humid superparamo of the study area are: Thamnolia vermicularis, Racomitrium crispulum, Bryum ar genteum, Grimmia sp., Stereocaulon vesuvianum var . nodulosum. Exc ept Thamnolia, these speci es ar e almost absent in the dry superparamos on the opposite side of the Cordillera. In contrast to the earlier mentioned Acaulimalva -Agrostis breviculmis me adow (25) , the Senecio niveo-aureus community is widely distributed b e t ween 4250 and 4350 m in superparamos 6n the humid side of the Cordillera , e.g . in

the Sierra Nevada del Cocuy (Arauca-slope) and in the Paramo del Almorzadero (Santander). Small stands were observed on the Nevado del Sumapaz (4100-4 230 m). The Senecio niveo- aureus cover decreases rapidly with height and only a few specimens were collected from 4350 to 4600 m. Patches of Senecio niveo- aur eus on ba re brownish-black soil with frost-heaving are also found in the bunchgrass paramo rockshelters on both sides of the Nevada del Cocuy. In the lower paramos the species grows in boggy valleys in CaZamagrostis ZiguZata mire, representing the coldest spots at this height (see CaZamagrostion ZiguZatae). Senecio ZatifZorus is a close allied vicariant species endemic to high paramos of the Colombian Cordillera Central. note: The population Senecio niveo-aureus in the upper condensation zone of the Nevado de Sumapaz is associated with VaZeriana pZantaginea . Here the Senecio niveo- aureus rosettes are morphologically different from those of the Sierra Nevada del Cocuy populations by I) slender lax plants with lower stature; 2) smaller and narrower lanceol a te acuminate leaves , leaving the stem visible, and 3) loose panicles with less flowers (10-20) in comparison with the e longa ted contracted compact raceme containing more flowers ( 20-30). The Cocuy population is morphologically rather similar to. that of the Almorzad ero. Th e morphological differences between the distinct superparamo populations of the Colombian Cordillera Oriental perfectly reflect their isolation. The greatest differences can be noticed between the Cocuy and Sumapaz populations, which at pr e sent and during the entire Pleistocene always wer e separated (Vander Hammen 1974; Vander Hammen & Cleef, in press).

27.

Community of VaZeriana pZantaginea with Racomitrium crispuZum Fig. 32 & 58; lit .: Zander & Cleef, in press.

This rosette-bryophyte community is common on rocky slopes and outcrops with a humid thin (less than 10 em), discontinuous, brownish, stony soil in the humid superparamo of the upper condensation zone. Large VaZeriana pZantaginea rosettes with dark greenish, fleshy leaves and white to lilac flowers are characteristic and the species is generally associated with Racomitrium crispuZum, Erigeron chionophiZus , PoZystichum sp., AZtensteinia paZudosa, ft1ontia meridensis and with rosettes of Senecio niveo- aureus and Draba spp. In superhumid upper condensation zone environment,as prevailing on the Nevado de Sumapaz, bro\vnish mosses (e.g. Rhacocarpus purpurascens, Racomitrium crispuZum) and reddish liverworts (Herbertus subdentatus, H. acant heZius ) are predominant, cove ring up to 60%. The bryophyte layer is rich in species, e.g. PZagiochiZa dependuZa, Kingiobr yum paramicoZa, RaduZa sonsonensis, Ricc~~dia

waZZisii, Gymnomitrion truncato-apicuZatum, AnastrophyZZum BZinda acuta, and BreuteZia integrifoZia . Most of these are

Zeuc~ stomum ,

known also from other high areas reaching into the upper condensation zone. Studies in this zone in the Colombian Cordillera Central showed that RacomitriUm crispuZum dominates zonal rocky vegetation, whereas Rhacocarpus purpurascens was only noticed in azonal wet patches (Cleef et al., in press). Rhacocarpus purpurascens is dominant on zonal rocky soil in the lowermost part of the distinctly more humid lower superparamo of the Nevado de Sumapaz (4000-4100 m), where Racomitrium cr ispuZum is subdominant. Towards higher parts (4200- 4250 m) Herbertus acantheZius takes over together with H. subdentatus , which is more common on rocky soil. This last species forms a ring-like pattern on humid clayey soils. Frost-heaving is daily event in th e humid, bare soils. VaZer iana pZanaginea - superparamo has a curious

purple-reddish colour at thi s height. The th i n soils are silty or gravelly and in the study area, they are derived from calcareous rocks. The pH of the brownish- black to da rk gr ay lithosol is 5.4 to 6.0. At 4200 rn still the presence of earthworms was noted. The Valer iana plantaginea - Racomitr ium crispulum community has been studied be tween 4050 and 4250 rn on the Nevada de Surnapaz and n ear Patio Bolos in the Si erra Nevada del Cocuy. Communities ' without Valeriana plantaginea were studied in the upper reaches of the Paramo del Alrnorzadero at 4250 rn. The community was also noticed on the high vol canoes of the Colombi an Cordillera Central from 4250 to 4400 rn (Cl eef et a l. , in press), and it is supposed to be pre sent also in Ecuadorian high and humid pararnos. 28.

Other zonal lower superpararno communities

Both following superpararno communiti e s were observed locally, and only few phytosociological data have been collected. a . Lachemilla nivalis vegetation is optimally developed at 4100 rn on the Nevada de Surnapaz, where it is in contact with the Loricarietum complanatae r acomitrietosum (Fig. 29) . Grayey Lachemilla nivalis ros e ttes, which are woody at their base, apparently replace Loricaria shrub on flat ridges with thicker (about 30 ern) soils . Prostrate runners of Arcytophyllum nuticu.m cover the op en space s between the Lachemilla nivalis ros e tt es, wh il e Cladonia isabellina is common under the s e rosettes. Radula wallisii is abundant here on decaying Lachemilla nivalis. The pH of the upper sandy to calyey black soil laye r is 4.9. In the lower superpararno of the northern Andes. Lachemilla nivalis is quite common and forms locally characteri s tic stands, which, when more rel eve s will be avail ab l e, perhaps may be described as a proper syntaxon. b . Niphogeton josei dwarfshrub vegetation (up to 25 ern hi gh) was ocaasionally observed be tween 4270 and 4340 rn in the sandy and grave lly zonal lower superpararno in the Sierra Nevada del Cocuy, e. g . near Patio Bolos, and commonly on the Alto Nievecitas. In the latter locality, the endemic Niphogeton josei covers about 25% and is' associated with Senecio cleefii, another low shrubby species tha t partly replaces Pernettya prostrata var. prostrata on the cloudy side of the Cocuy range. Note: The Drabetum pamplonensis Vareschi 1953 is apparently a zonal sup'e rpararno community of the Sierra Nevada de Herida, Venezuela, which has not yet been found in Colombian pararnos; though Draba pamplonensis .was ori ginally described from the Colombian Cordillera Oriental . U p p e r

s u p e r p a r a rn o

In the Colombian Cordil l era Oriental an upper superparamo zone is only present in the highest areas of the Sierra Nevada del Cocuy, from 4500 to 4800 rn. There are no floristic differences with the lower superpararnos, except the number and cover of species, which are distinctly decreasing near the snowline . A few vascular plants may grow in protected places, e.g. Cerastium sp., Luzula cf. racemosa, Senecio niveo- aureus. Poor specimens of Stereucaulon vesuvianum var. nodulosum, and some bryophy tes (Racomitrium crispulum, Dicranac eae and Bryaceae) are present closest to the snowline. Depending on substrate and physiography, the plantcover is related to the various zonal communities of the lower superparamo (e.g. 23, 26 & 27)

Ill.

THE AZONAL PARAMO VEGETATION

AQUATIC COMMUNITIES

Ditricho submersi - Isoetion all. nov. type: Isoetetum karstenii (this study); tabl e : 3 This alliance comprises mainly submerged Physiognomy & synecology: bryophytic-isoetid communities in paramo lakes. Only in the highest and in the shal l owest lakes bryophytes may be absent. The species of Isoetes vary Ln height from 2-3 em (Isoetes .socia) to about 60 em (I. cleefii). Species abundance and organic content of the topsoil increase from superparamo lakes towards lower altitudes. The substrate shows all . kinds of texture, varying from s~ones and gravel to clay and gyttja (Fig. 90). Composition & syntaxonomy: Exclusive and selective character species are Isoetes karstenii, I. glacialis, I. socia, I. andicola, I. cleefii, I. palmeri, a ll species of the section Laeves Fuchs; further Ditrichum submersum, Blindia magellanica (rare), Herbertus oblongifolius (rare), Isotachis serrulata, I. lacustris . Preferential character species are

Fissidens rigidulus, Sphagm路m pylaesii, Fontinalis bogotensis, Riccardia paramorum and Batrachospermum sp. There are 1- 2 species in the communities at the highest altitudes and about 7 in the Isoetetum palme!'1:. On the basis of iloristics and eco lo gy this alliance can be subdivided into several associations and one unranked community. Presence, type and nature of bryophy tes determine additional subdivisions, Id entifications of the collected Isoetes spe~imens by Dr. H.P. Fuchs provided the floris tic basis for the associations and communiti es within the Ditricho-Isoetion. The 1soetetum lechleri Gutte 1980 is likely to belong to this new alliance. The syntaxonomic position of this quillwort vegetation, however, will remain uncertain until the specimens of the species have been identified by a specialist. Distribution: The alliance has been studied in the paramos of the Cordillera Oriental between 3350 and 4450 m. Judging from plant collec tions and field observations, the Ditricho- Isoetion must be present all over the northern Andean paramos from Venezuela to Ecuador, extending south to Bolivia (Isoetetum glacialis) and Peru (Isoetetum sociae, Isoetetum andicolae). Phytogeographical comments and early evolution of aquatic paramo b~ot~ All Isoetes species representing proper associations or communities in the Ditricho-Isoetion belong, according to Fuchs (in press), to the section Laeves, which apparently evolved in the Neo- tropics. The section Laeves of Isoetes seems to be almost endemic to the high tropical Andes, and the highest differentation and spec i ation is found in the northern Andean paramos (Fuchs , in press). Vander Hammen et al. (1973) recorded the first Isoetes microspores in old Pleistocene sediments ("Guasca 2") <)f the Colombian Cordillera Oriental. which were dated at about 3.6 (~ 0.67) millions of years . They are assumed to have belonged to early members of the section Laeves of Isoetes. Potamogeton berteroanus (Dr. L.B. Holm-Nielsen, in litt.), Hydrocotyle ranunculoides,

Myriophyllum elatinoides and Elatine chilensis (?) are of~austral or~g~n. Austral-antarctic elements prominent among the bryophytes ) are e.g . Isotachis sect . Subaequifolia, Blindia magellanica,Cryptochila grandiflora, Clasmatocolea vermicularis, Fissidens rigidulus and Jensenia erythropus. The genera l occurence of members of this section of Isoetes in paramo lakes, to ge ther with a high proportion of other austral - antarctic aquatic plant taxa (Cleef 197 8, 1979b), support the assumption tha t paramo lakes were mainly colonized by temp era te plant taxa af ter the early Pleistocene. 29. Isoetetum karstenii ass. nov. type: rel . 461; t able 3; Fig. 33 lit.: Cl eef et al., in press . Physiognomy:

The open to more or less closed layer of clumps of

Isoetes karstenii, .10 to 20 ctn high, are associated with hi gh bryophytes, excep t in the hi ghest sup erparamo lakes. The water in these lakes is generally transluc ent. Isoetes karstenii has long roots , which prevent the plants to be removed by mechanical forces such as wave action, strong currents , etc. Composition & syntaxonomy: Isoetes karstem:i is present in a ll releves. In lower areas a few species of bryophytes were found, e.g. Ditrichum submersum, Isotachis serrulata and Blindia magellanica. Th e last-mentioned species has only been recorded as far south as the t ype locality in southernmost S. America. Filamentous algae may cover up to 80%. In 8 rel eves the average numb er of species is low , i.e. I in the hi ghest lakes to 2 ( 1-3) in the lowermost. Exc lusive character species are Isoetes karstenii and Blindia magellanica. The association can be divided into subassociations, differing in presence of aquatic bryophytes. Synecolo gy: The Isoetetum karstenii grows mainl y in deep, cold lakes in the upper part of the piiramo be lt. Host miner a l soils are silty, but some clayey and stony s ub s trate have been observed near the shores. Gravelly sediments are common in places with wind and wave action. As a result of its low organic content, the wat er is rather transp ar ent in these l akes. The few .pH data vary from 5.2 (lakewater at 4400 m) to 6.1 (calcareous sediment at 4100 m). With increas ing depth or elevation, Isoetes karstenii d ecr eases in height and cover. The cover of Ditrichum submersum increases with a better prote c tion against wind and wave ac tion and with increasingly favourable temperatures . Distribution: The Isoetetum karstenii is described from the piiramos of the Colombian Cordillera Oriental (Cocuy, Sumapaz), from the grasspiiramo at (3500--)3700 m up to the superpihamo at 4425 m. This association h?-s also been studied in the Sierra Nevada de Herida (Venezuela) at 4250 m and at 4300 m on the volcano S. Isab e l ,Co l ombian Cordillera Central. According to Fuchs (in pre s s and in litt.) Isoetes karstenii is known from Venezuela ( 2500-4250 m) and Colombia (3200- 4425 m).

*) For further phy togeographica l analysis of the aquatic bryoflora of the Ditricho- Isoetion, see under the Isoetetum palmeri (34).

29a. Subass. t ypiaum subass. nov. type: rel. 449; table 3; Fig. 33 Physiognomy: This submerged community consists of a more or less open isoetid field layer up to 25 em high, depending on waterdep dj and altitude. Composition & Syntaxonomy: Is oet es karstenii is the only vascular plant, and has a cover of 5-80%. Filamentous green (and blue ?) algae generally cover .the I soe t es kars tenii clumps. Mosses are absent. This new described subassociation is characterized by the character species I s oetes kars tenii and by the absence of other cormophytes. The subassociation typiaum has its closest affinities to the Is oetetum karstenii ditriahetosum, which is common in deep lakes in the lower paramos. The subassociation typicum is delimited here as a syntaxon for the superparamo and in fact represents apioneercommunity preceeding (in time and space) the I soetetum

kar steni i di t r i chet osum. Synecology: This high altitude isoetid community o c cur s submerged in deep superparamo lakes from the shore to at least 150 em depth. I soe t es karstenii cover is much lower in the deepest parts. Throughout the year water temperature remains low in these cold polymictic lake s. They are never fro zen, ex cept ne ar the shores. In more shallow water, the cover of Isoetes karstenii increases in some places up to 80%, apparently due to more prote ction (Fig. 33). The blue- grayish clayey to silty and sandy lake s ediments are thi ck (at least 100 em). Wind and waves often cause turbul ences with fine soil particles. Strong wave action and quicksands may bury the Isoetes karstenii . The roots of I soetes karstenii are l onger than the large, stiff dark-greenish leaves ( 20-25 em). Wind and wave a ction, and thus turbulence b e come stronger in路 hi gher areas with deep glacier lakes near the snowline. Unstable soils and low temperatures combined with high altitude, turbulanc e and depth of the lake represent limiting factors for the development of the Isoetetum karstenii typicum . A single pH for lake water is 5.2 (rel. 323). Lakes containing this s yntaxon or the Is oete t um sociae probably yield the lowest primary production of all lentic waters of the paramos . Consequently, aquatic fauna is scarce in this subassociation. Near rel. 323, Gammarus sp. has been observed and small sanderlings foraging on these small crustaceans. Distribution : The subassociation t ypicum is only known from (deep) superparamo lakes in the Sierra Nevada del Cocuy (Boy aca) between 4350 and 4425 m, and from the volcano S. Isabel (4300 m) in the Colombian Cordillera Central. 29b. Subass. di trichet osum subass. nov. type: rel. 461; table 3; Fig. 33 Physiognomy: This submerged vegetation is more or less closed, and consists of a 10- 25 em high isoetid-bryophytic layer. Erect bryophytes may be dense between the Isoetes foli 路a ge.The Isoetes herb layer is maxima,lly closed in protected stands. The habit of the rare Blindia magel l anica (in rel. 271) is similar to that of Ditrichum submer sum. Composition & syntaxonomy : Is oetes karstenii is the only prominent vascular species, as a rule accompanied by Di triahum submersum, I sotaahis s errulata and in some places by Blindia magel lani ca . The two last species are representatives of the austral - antarctic element. These bry ophy te species are differential against the Is oetetum kars t enii typicum .

Synecology: This subassociation is characteristic on mineral bottoms (e.g . clayey-silty and sandy-stony substrates) of deep high paramo lakes. These grayish sediments are poor in organic content, but become brownish and richer in organic matter at lower heights. Erosion by wave action or current s of the ori~inal clayey deposits overlying the gravelly floor is common (e.g. rel. 1 ). The pH of 6.1 in a calcareous sediment in rel. 271 on the Nevada de Sumapaz is probably not representative for other stands in the Sierra Nevada del Cocuy on non-calcareous substrate, which is about 5 . 5 - 6.0. Gammarus and small black leeches are common in the habitat of the Isoetetum karstenii ditrichetosum. Many Copepodawere collected in rel. 271 at 4100 m. Distribution: The Isoetetum karstenii ditrichetosum is described from deep lakes in the high paramos of the Sierra Nevada del Cocuy and the Paramo de Sumapaz . It is distributed from the grass paramo at 3750 m up to the superpiiramo at 4350 m. A few specimens of Isoetes karstenii have been collected as low as 3200 m in the Paramo de Sumapaz (Fuchs, in litt . ) 30.

Iso e tetum gZaciaZis ass . nov . (prov.) type rel . 161A; table 3; Fig . 34

Physiognomy: The closed, dark green-brown isoetid layer, up to 40 em high, is fo und on deep lake bottoms . The root system is very dense and at least 30 em deep. Composition & syntaxonomy: In both releves Isoetes gZaciaZis, the only character species, is dominant (cover 90-100%) and associated with CaZZitriche sp. near the shores. The number of species is low (1-3) in 2 releves. Synecology: This submerged association covers thick gyttja deposits, mainly in grass paramo lakes. The dense Isoetes gZaciaZis vegetation hardly leaves enough space for other plants and only Ditrichum submersum is regularly associated. This community extends up to the low-water line for the dry season. The Isoetetum gZaciaZis in the Laguna Cuadrada (Sierra Nevada del Cocuy) became temporarily visible towards the end of the extremely dry season in March 1973. It remains unknown , however, whether the Isoetetum gZaciaZis or NiteUa (Characeae) communities occur in the deepest part of this lake. The pH of the sediment in the shallow margin (TiZZaeetum, rel . 161) was 5.4 . A"pollendiagram for this lake (VL III, plate 3) was published by Gonzalez et al. (1965). Distribution: The association is described from glacial lakes in the high valley of Lagunillas in the Sierra Nevada del Cocuy between 3900 and 4000 m. Isoetes gZaciaZis has also been collected in the shallow near-short part of the deep lakes near the Nevada de Sumapaz at 3425 m. scarce isolated clumps of Isoetes gZaciaZis are found in the Isoetetum paZmeri, the Potamogeton - Myriophyllum eZatinoides community and in the EZeocharitetum macrostachyae. The Isoetetum gZaciaZis is believed to be present also in the deeper parts of the lakes. The association is probably also present in other tropical Andean lakes, for Isoetes gZaciaZ1:s was described as a new taxon from the Bolivian Andes (Prov. Hurillo near La Cumbre) at 4700 m.

31 .

Isoetetum sociae ass. nov . type rel . 338; table 3; Fig . 35 lit.: Weberbauer 1911 Physiognomy :

The open isoetid layer consisting of tiny plants of

Is oetes s oci a is found in shallow lakes and ponds in the high paramo. Composition & syntaxonomy: The dominant and nearly only vascular species is Isoe tes socia . EZatine cf. chiZensis and Ditrichum submersum may be present; the first one in ponds in the grass paramo, the last t wo in slightly deeper lakelets that do not fall dry through evaporation. Green and blue algae may be floating in the shallow, clear water, e.g. Mougeotia sp. (S703) and desmids. The average number of species is 2 (range 1-4) in 8 releves. Isoetes socia is the only character species of this high altitude syntaxon. There are no other vascular species in the superparamo Stands, but in the lowermost releve EZatine cf. chiZensis is found together with Isoetes soci a . In the lower paramos the Is oe tetum s oci ae is replaced by the TiZZaee tum which ecologically shows a number of similarities with the I soete tum s ociae (Fig. 91A). The Isoetetum sociae is ranked under the Ditricho-I s oetion because of the floristic composition (Is oe tes, Di t r ichum submersum) and the predominantly isoetid lifeforms in the association. Synecology: The Isoe tetum s oci ae is found in the high paramo on the bottom of small, shallow lakes and ponds, which may fall dry in the dry season. Then a . crust of algae covers the Isoetes socia plants and part of the bare mineral bottom. The tiny Isoet es socia plants thus survive this dry period by this kind of protection and by their corms being buried in 1-2 em deep, still humid soil. During most of the year, however, the Isoete tum sociae is submerged in SO (-100) em . The substrates are mostly less than SO em thick. The thin toplayer is clayey to silty, in other places coarse-sandy. The pH of the top layer is 4.8- S.7, in superparamo sediments slightly above S.O. The temperature of the water in these shallow lakes and ponds increases on sunny days and may main high in the early hours of the evening, but in the early morning, the water may be frozen however. At S.30 p.m. on September 30, 1972 the temperature of the water in a shallow lake (rel. 168) and the atmospherical temperature at 4400 m on the Cuchilla Puentepiedra in the Sierra Nevada de l Cocuy were resp. 130 and S째C. Thus, environmental conditions in these shallow high paramo lakes with the Isoetetum sociae are much more fluctuating than in the deeper paramo lakes with the Isoetetum karstenii. The Isoet etum sociae is subjected to I) dry periods, 2) irregular sedimentation, 3) a wide diurnal temperature range, and 4) foraging animals . . (SyZviZagus may eat fresh Is oe t es soci a foliage, when the plants are above water). Desiccation by evaporation apparently is the most extreme environmental factor. Is oetes soci a is a specialized species well adapted to this harsh environment. It is the only amphibious vascular plant forming communities near the snowline (Fig. 91A). Distribution: The association is described from the high paramos (upper grass paramo & superparamo) in the Sierra Nevada del Cocuy between 4000 afid 4400 m, and from the Paramo de Sumapaz (Chisaca) at 3700 m. Isoet e s socia was originally described from the Merida Andes, Vene z uela. The Isoetetum sociae may thus be expected in other high parts of the tropical Andes; Weberbauer (1911) reported Isoetes socia, CrassuZa bonariensis and RanuncuZus mandonianus from 4400 m in the Peruvian Andes (Ancash) without indicating the cover. It remains to be ascertained whether the Is oete t um s oci ae, the Is oetetum kars tenii or the TiZZaeetum paZudosae is present in this region.

32.

Isoetetum

andicoZae ass. nov. type: rel. 292 A; table 3 & 4; Gutte 1980: table 5 Fig. 36 (this study); Raub & Falk 1959 : Fig. 6 (p. 17) photo: Rauh & Falk 1959 : some excellent photographs lit.: Rauh & Falk 1959, Raub 1978, Gutte 1980

Physiognomy: Isoetes andicoZa forms distinct long, boggy hummocks, up to 80 em thick, along the mineral shores of tropical high Andean lakes. Hundreds of stiff-leaved specimens with dichotomous stems grow close together in firm cushions, on which one can walk, at least in the dry season. Composition & syntaxonomy: Isoetes andicoZa is the main vascular plant and the character species. In lakes of the grass paramo Isoetes karstenii, CaZZitriche sp., TiZZaea paZudosa and EZatine cf. chiZensis may be companion species. On the basis of the floristic composition the Isoetetum andicoZae must be assigned to the Ditricho-Isoetion.

Table 4

Isoetetum andicoZae ass. nov. author & rel. no. locality alt. m rel. area (m2) pH

Cleef 292A

Raub & Falk 1959 (s.n.)

3620

4750

thickness bog (em)

20-60

-80

I 00 I

100

Gutte 1980 table 5, rel.4 c 4700

Gutte 1980 table 5, rel. 5

4700

4.8 (lakewater

5.5-5.8) ÂŁÂŁ~H=~ c & o taxa

Isoetetum and1'coZae: Isoetes andicoZa Isoetes karstenii CaZZitriche sp. TiZZaea paZudosa EZatine cf. chiZensis LachemiZZa dipZophyZZa Plantago rigida Oritrophium ZimnophiZum

(5)

(I)

a Paramo de Sumapaz; Laguna del Media b Peru: Casapalca (Cord. Occ . ) Laguna Caprichosa c Peru: Yauli, Morococha, Base Puypuy pH of the lake water near the stand in the neighbouring Laguna La Primavera was determined at 6.4 ++) cover according to Braun-Blanquet scale +)

(+) (+)

Synecology: The peat on lake sediment under the Isoetes andi cola cushions consists of remnants of this remarkable quillwort species and thick layers of whitish macrospores. It forms a considerabl e contribution to the lake sediments. The Peruvian stands were found in water-loaded hollows in hydroseral Distichia muscoides bogs (Rauh & Falk 1959, Gutt~ 1980). Is oetes andi cola peat has been reported by Rauh & Falk (l.c.). Appar ently no other associated species were found. Raub & Falk (l.c.) also provided pertinent data on ecological conditions, and published a line transect through hydroseral communities at 4750 m altitude in a Peruvian l ake. The pH of the lakewater is 5.5-5.8 in the Peruvian Laguna Caprichosa at 4750 m, and 6.4 in the Colombian Laguna La Primavera at 3500 m. I s oetes andicola peat in the Peruvian type locality showed a pH of 4.8.

Is oetes andicola is known from several localities in the Distributio~: Peruvian Andes (prov. Lima, ~unin, Puno) between 3800 and 4780 m. In the Colombian Paramo de Sumapaz (dept. ~1e ta), Is oetes andicola was collected (Cleef 7555a & 8247) in the Laguna La Primavera and Laguna del Medio in th e lower grass paramo of the upper Sitiales vall ey ,NW of Cerro Nevado between 3500 and 3620 m. The Is oete tum andicolae may eventually be found in the Ecuadorian paramos and in the paramos of the Colombian Cordillera Central. Note: Isoete s andi cola was described from the Peruvi an high Andes. Rauh & Falk (1959) presented a d e tailed morphological and sy stematical study on Stylites E. Amstutz em. W. Rauh. The present author prefers to follow Dr. M.T. Murillo, Bogota (pers. comm.), and Fuchs (1981a, 1981b), who cons id er the genus Sty lite s as congeneri c with Is oetes: Is oetes andicola (E. Amstutz) H.P. Fuchs, belonging to the section Laeves H.P. Fuchs. Stylites gemmifera W. Rauh is regarded to belong to the .morphological range of Isoetes andicola The presence of I soe tes andico l a in the Laguna del Medio and the Laguna La Primavera in the Paramo de Sumapaz is of considerable phy to geographical interest. The species represents the first record of this species in the paramos of the northern Andes and is new to Colombia. 33.

Is oet etum cl ee fii

ass. nov. type: rel. 301; table 3; Fig. 37

Physiognomy: The high (20-60 em) dense isoetid communities are found on clayey (to gyttja) - sandy bottoms of grass paramo lakes . Composition & syntaxonomy: I soetes cleefii is the character spec~es (exclusive), only known from the par.amos in the study area (Fuchs, 1981 ). The taxon is closely related to I soetes pa lmeri , but is different by its broader leaves and rhizomes, and by its triangular velum completely covering the sporangium, which is twice as large as in 1. paZmeri . Cryptochila gr andifloro and Calypogei a andi cola are diagnostic species . According to Gradstein et al. (1977) this is the first record of submerged Calypogei a andicola . The number of species is 4-5 (3-6 in 4 releves). The low number of species is differential against the Is oet etum palmer i (34). Synecology: The association may be found in clear lakes in the high grass paramo mainly surrounded by mineral shores. The pH value s of the wa t e r a r e 5.1-5.7. Bryophytes are common on the clayey organic sediment between the Is oet es clumps and also between filamentous algae. Sylvilogus and/or Cavia

forage on the emergent layer of Isoetes herbs in the dry season. Distribution: According to Fuchs (1981b) this taxon, and thus also this isoetid community, is present between 3750 and 4250 m in the Colombian Cordillera Oriental (Sumapaz- Rusia - Cocuy). Note: A pollendiagram of the Laguna Gobernador (type rel. 301, 304) in the paramo de Sumapaz has been prepared by Mr. Guido B.A. van Reenen and will be published in the near future. It covers the Late Glacial and the Holocene. 34.

Isoetetum palmeri ass. nov. type rel. 190; table 3; Fig. 38

Physiognomy: The association consists of a submerged, mostly closed aquatic bryophytic-isoetid layer. Elodeids and amphiphytes may be present with low cover. Composition & syntaxonomy: The most prominent species is Isoetes palmeri. Other species with low cover values may be present too. Several accompanying herbaceous amphiphytes are characteristic, at least in near-shore localities, e.g. Cailitriche cf. nubigena, Tillaea paludosa and Elatine cf. chilensis. Other conspicuous sp,ecies are Potamogeton berteroanus, Eleocharis acicularis and Hydrocotyle ranunculoides. Attached and/or floating bryophytes are common, e.g. Ditrichum submersum and Isotachis serrulata. A number of characteristic aquatic bryophytes have low frequencies. Many of these belong t6 the austral- antarctic flora element (see under Ditricho-Isoetion). Sphagnum cyclophyllum and the rare S. pylaesii represent the holarctic element. According to Florschutz- de Waard & Florschutz (1979), this is the first record of the common Sphagnum cyclophyllum in _Colombia. Ditrichum submersum, Fontinalis bogotensis, Riccardia paramorum, Radula episcia (Jans 1979) are tropical Andean species and Drepanocladus exannulatus, Scorpidium scorpiodes (including S. turfaceum Herzog) and Sphagnum cuspidatum are cool temperate in distribution. Drepanocladus exannulatus and Sphagnum cuspidatum are locally abundant. Filamentous algae are common also. Most characteristic is Batrachospermum sp. (Rhodophyta). In addition, several species of Zygnema, Spirogyra, and cf. Microspora have been identified by Dr. A.J. Dop. With an average of 7 (2-15) different taxa in 9 releves the Isoetetum palmeri rep~esents the paramo community dominated by Isoetes richest in species. The common character species is Isoetes palmeri. Rare character species are Sphagnum pylaesii (excl.), Riccardia paramorum, Fissidens rigidulus (pref.), and Batrachospermum sp. (sel. ) . The remaining bryophyte species may be considered as differential against the other aquatic - paramo communities in this area. Callitriche sp.(p.),Elatine cf. chilensis and TiUaea paludosa are differential against most other syntaxa of the Ditricho-Isoetion. The low cover of Tillaea is also differential against the Tillaeion. In the Isoetetum .palmeri, two mossy variants can be recognized, by the high cover either of Drepanocladus exannulatus or of Sphagnum cuspidatum. Synecology: The Isoetetum palmeri is restricted to clayey and peaty sediments in paramo lakes (partly) surrounded-by bogs or to boggy areas. This association occurs in peat-bottomed lakes and lakes with peaty lake sediments, in the lower part of the paramo belt. Lake.floors are covered by the Isoetetum palmeri almost up to the low-water line in the dry season, when the tops of the Isoetes leaves may be visible above water. The presence of this association depends on water depth rather than on size of the waterbody. ~1aximum water

89 depth for the Isoetetum palmer.i is unknown, but is at least 2.5 m, judging from (personal) observations. Sediments are clayey or peaty; peat tends to form a dark gyttja. The organic content of most lakes in boggy paramo causes the relatively low pH from 4 . 6 to 6.4 and generally about 5.0.. Drepanocladus exannulatus or Sphagnum cuspidatum may be prominent in the field layer of the Isoetetum .palmeri in lakes next to Sphagnum bogs. In most releves up to 4435 m, species of Gammarus (Amphipoda, Crustaceae) and small black and brown leeches (Hirudinae) were noticed, and Coleoptera, worms and other waterinsects are common . Rel. 264 (3550 m) contained tiny whitish shells of freshwater bivalves, Sphaerium lauricochae Philippi . Distribution : The Isoetetum palmeri is described from the subparamo and grass paramo of the Colombian Cordillera Oriental. Most stands were studied between 3350 and 3850 m. Rel. 327 was made in a small 'superparamo lake at 4435 m, surrounded by marshy ground with dense bunches of Calamagrostis sp. (8652). According to Fuchs (198la), Isoetes palmeri is a true paramo species, geographically restricted to Venezu.e la, Colombia and Ecuador . Its vertical distribution is from forest line at 3200 m to the superparamo at 4400 m (Cocuy, Chimborazo). The Isoetetum palmeri is probably native to the northern Andean paramos from Ecuador to Venezuela. 34aa. Variant of Drepanocladus exannulatus type: rel . 200; table 3; Fig. 38, 39 (also Fig. 34) Differential species is Drepanocladus exannulatus, which is mostly dominant (submerged or floating), and lowers the cover of Isoetes palmeri. The lakewater is oligotrophic and the variant has been recorded only near the shore of peat-bottomed lakes surrounded by Sphagnum bogs . Releves are located in the Calamagrostis effusa bunchgrass paramos at 3700 m in the southern part of the area. 34ab . Variant of Sphagnum cuspidatum type: rel. 97; table 3

Sphagnum cuspidatum is a differential species , and thalloid aquatic hepatics may be common . This variant has been recorded for small lakes on Sphagnum bogs . The trophic level (pH 4.7-5.2) of the lake water presumably is relatively low. The Sphagnum cuspidatum variant is common in the peaty bamboo paramos between 3350 and 3600 m on the humid side of the Colombian Cordillera Oriental. 35 .

Community of Isoetes boyacensis table 5

Although Isoetes boyacensis was a common dominant in several ponds in El Tutal ' between 3800 and 3900 m on the southern calcareous slope oÂŁ the Paramo del Almorzadero (Santander) , only a single releve has been sampled on November 20, 1978 .

Table 5 Community of Isoetes boyacensis rel. no. size soi l depth alt. loc.

575 2 rn2 c 10 ern 3825 rn Alrnorzadero; El Tutal

cover %

Isoetes boyacensis Ranunculus limoseUoides

100 10

According to Dr. H.P . Fuchs (in litt.), the dominant Isoetes species (Aguirre C. & Cleef 1050A) is new and ye t to be described. It is unknown whether Isoetes boyacensis (sect. Terrestres)is restricted to pond s in the Paramo del Alrnorzadero, or whether this s pecies is common in other shallow waterbodies in th e northern paramos of the Colombian Cordillera Oriental. This releve is provisionally classified within the Ditricho-Isoetion though Ranunculus limoselloides is. more common in the other alliances of aquatic habitats (see table 3).

TlLLAEETALIA order nov. (L I M 0 SELLE TEA type: Tillaeion paludosae (present study)

cl . nov. prov.)

The order Tillaeetalia is erec ted to comprise all Tillaea*Ldominated communities cha ract eri st ic for pond and lake-shore habitats at sea level in cool-temperate southern latitudes and at high elevation in tropical mountains. These aquatic crassulaceous Tillaea communities are dominated e.g . by Crassula granvikei Mildbr. (Hedber g 1964,. Coe 1967), Crassula natans Thunb. (Van Zinder en Bakker & Herger 1974), TiUaea moschata DC. (Huntley 1971; Gremmen 1981), Crassula moschata Forst. f . (Reiche 1907), Cr.assula erecta, Berger (Oberdorfer 1960) and Tillaea paludosa (th is paper), all of which are character species for associations in this new order. Noteworthy is the presence of vicariant species of Ranunculus with floating leaves: e.g. Ranunculus volkensii Engl. (Kilirnanjaro), R. biternatus Sm. in Rees (Subantarc tic Zone), R. mandonianus l,ledd. (Peru, Bolivia), R. limoseUoides (Peru- Venezuela) and R. spaniophyllus (Colombia- Venezuela). The same seems to app l y also to some species of Callitriche . As a rule , these arnphiphytic communities are poor in species. The Crassuletum natantis Van Zinderen Bakke r & Werger 1974 contained on average 4.1 species (range 3-5) in 8 releves and the Tillaeetum paludosae (this paper) 4.3 species (range 1-9) in 10 releves. Grernrnen (1981) reported an average of about 5.0 species (range 2-11) in 32 releves from the halophytic Cotulo-Crassu letum moschatae Grernrnen 1981 of the islands Marion and Prince Edward. According to Oberdorfer (1960) the Crassula erecta communities on rocks along Lake Villarica in Chile contain no other phanerogarnic species; according to Reiche (1907), halophytic Crassula moschata communities on rocks along the Pacific beaches were associated either with Colobanthus quitensis or with Asplenium obtusatum Forst. In conclusion, all these Chilean communities are extremely poor in species. x) All herbaceous aquatic species of Cr.oassula belong in the author's opinion to

TiUaea

Substrates consist of a more or less clayey ooze with silty or peaty components. Most associations/communities occur in fr esh water. The pH of the water varies considerably: e.g. from 7 . 9 to 8.6 in the Lesotho bogs (Van Zinderen Bakker & Werger 1974), and from 5 . 9. to 6.4 in the paramos of the Colombian Cordillera Oriental. The pH in the rootzone of Tillaea was 5.2 in the Lesotho bogs, from 4.5 to 5.7 on Marion Island (Gremmen 1981) and varied from4.5 to 6.6 for the Tillaeetum of the Colombian paramos. Releves are not available from other parts of the tropical Andes and from equatorial Africa . Tillaea- or Limosella- dominated communities, however, seem absent on the New Guinean high mountains (Dr . J.M.B. Smith & Dr. J .F. Veldkamp, pers. comm.) . The Tillaeetalia should be comprised into the Limoselletea (classis nov. prov.), which includes the Tillaeetalia (type) and other related communities, characterized by the presence of amphibian Limosella spp.: e.g. L. americana Gluck, L. australis R. Br., L. lineata Gluck, L. aquatica L., L. capensis Thunb. and L. africana Gluck. Limosella australis, for instance, was fo und dominating pond vegetation on the high Colombian volcanoes (Cleef et al., in press) and on Marion Island (Gremmen 1981). The Limoselletea as provisionally outlined here repr e sents a tropical high mountain and australantarctic vicariant against the Litorelletea Br.-Bl. & R.Tx. 1943 em. Den Hartog & Segal 1964 described from the northern hemisphere. The genus Litorella (Plantag.) is not completely absent in southern latitudes, however; Litorella australis Griseb. is reported from various localities in the southern hemisphere. The Litorelletea australis (prov.) Oberdorfer 1960 apparently comprises local sandy beach communities in temperate South America. In the author's opinion the Scirpo-Limoselletum Oberdorfer 1960 from temperate Chile fits better in the Limoselletea prov. as here defined, than in the Nanojuncetea australis prov. Oberdorfer 1960, which according to Barkman et al. 1976, is not a valid name.

TILLAEION PALUDOSAE all.nov. type: Tillaeetum paludosae (present study); table 3 Physiognomy: These basically amphibian communitie s are dominated by a low mat of herbs. Charact er istic is a layer of small floating leaves, mostly belonging to geographically vicariant, amphibian species of Ranunculus. Composition & syntaxonomy: This alliance compri!:es a l l tropical high Andean pond and lake- shore communiti es in which Tillaea palludosa plays a major role. Character species include Limosella australis (pref. ), Pilularia cf. manconi (excl. ), and Tillaea paludosa (sel.) . Tillaea vene~~ elensis Stmk. must be a synonym of Tillaea paludosa. This conc lus ion is b~sed on the examination of the type of T. venezuelensis. Differential species are A lopecurus aequalis Sobol, and to a cert路ain extent also Ranunculus limoselloides, and other geographically vicariant species: R. spaniophyUus ,路R. mandonianus Hedd. The high cover of the (dominant) Tillaea paludosa is also diff e rential against all other aquatic communities in the study area . Amphibian Ranunculus species and species of Isoetes sect. Laeves generally have a low cover. The numb er of species varies from 1 to 5 (range 1-9) in 24 releves. Synecology: The allicance is general l y found in shallow water of small paramo lakes and ponds, or along ~he shores of large and deep paramo lakes. The Tillaeion is restricted to mineral (c layey and silty) soils, the pH of

which varies from 4.8 to 6.6 in the upper root zone. The pH of the water is 4.7 to 6.4. Small waterbodies in the grass paramo tend to have oligotrophic conditions, whereas those in higher areas (superparamo) are mes otrophic. The stands along the shores of the large paramo lakes clearly reflect more eutrophic conditions. Due to the shallowness of the water and the characteristics of the paramo climate, water temperature fluctuate during a 24 hours period. Smith (1975 b) described the characteristic Ranunculus species with floating le,.aves as perfectly adapted to the amphibian environment. He found that Ranunculus sphaniophyllus rapidly produced long-petioled leaves in an artificially flooded stand at 3600 m in the Venezuelan Andes. This alliance contains sensitive and delicate species, which cannot endure grazing by cattle. See further under community 37. Distribution: The alliance is known at present from the high Andes from Venezuela to Peru. Releves were made in the Colombian paramos of t~e Cordillera Oriental (3330-4250 m) and in the Cordillera Central in the Parque Los Nevados (3700-4200 m). Our observations and herbarium data indicate that the Tillaeion paludosae occurs in the Venezuelan Andes between 3600 and 4250 m. 0llgaard & Balslev (1979) reported a stand at 3350 m in a small pond near the Laguna Papallacta in the Ecuadorian Cordillera Oriental. A community with Crassula bonariensis (= Tillaea paludosa ?), Isoetes socia and Ranunculus mandonianus, mentioned 路by Weberbauer (1911) from the Cordillera Negra near Caraz in the Peruvian Andes at 4400 m might also belong to the TilZaeion paZudosae. Herbarium collections (Liogier 21572, Mandon 1460, NY) indicate that a TiZZaea aquatica L. (= T. paZudosa in the author's opinion) - dominated community may be present at 2200 m in Valle Nuevo on Hispaniola, and in the Bolivian Andes.

36.

TiZZaeetum paZudosae ass. nov. type: rel. 41; table 3; Fig . . 39, 40 & 41 lit.: Weberbauer 1911; Ruthsatz 1977

Physiognomy: This basically amphibian herb~ceous association is characterized by a practically closed (about 1- 10 em high) dense bright green layer of TiZZaea paZudosa. Other vascular plants may root in the TiZZaea layer. Shallow waterbodies may contain a layer of floating leaves of mainly RanuncuZus ZimoseZZoides, AZopecurus aequaZis and sometimes CaZZitriche sp. (up to 40 em). LiZaeopsis schaffneriana and Juncus ecuadoriensis may be present with part of their foliage and inflorescenses exposed. Flowering in this association only shows whitish to greenish petals. Apparently, most dicots are autogamic. The cleistogamic TiZZaea paZudosa and Elatine chiZensis are only flowering路 and fruiting when they emerge in the dry season. Physiognomically a strong resemblance can be seen with African high mountain vegetation: e.g. with the CrassuZa granvikii zonation in tarns on Mt. Kenya (Coe 1967) and Ruwenzori (Hedberg 1964). Hedberg (1964) described similar amphibious communities with SubuZaria montiooZa A. Br. ex Schweinf. (Cruc.), CrassuZa granvikii Mildbr., LimoseZZa afrioana Gluck, CaZZitriche stagnalis Scop. and RanuncuZus voZkensii Engl. (only Kilimanjaro) from the afro-alpine belt of several East African mountains. Van Zinderen Bakker & Werger (1974) described a CrassuZetum natantis from pools in the Lesoth.o mountains at 3200 m, which is strikingly similar to the TiZZaeetum paZudosae as regards vascular generic compos~t~on, richness in species, synecology, structure, life and growth forms.

Composition & syntaxonomy: TiZZaea paludosa, the crassulaceous, aquatic, selective character species is dominant. Its cover varies from 35 to 100% with an average of about 80%. Other character species are LimoseZZa australis (sel.) and Pilularia cf. mandoni (excl.). Alopecurus aequalis is considered a differential species.Isoetes spp. (e.g. I. palmeri, I. glacialis) may be present with varying cover (1-25%), just as some other aquatic herbs, e . g. EZatine chilensis (especially in the isoetetosum) Ranunculus ZimoseZZoides, CaZZitriche sp(p)., EZeocharis stenocarpa and Lilaeopsis schaffneriana (especially in the subass. typicum). Incidentally present are Cardamine sp., Juncus ecuadoriensis, EZeocharis acicularis and Potamogeton asplundii. ~fosses are sparse and liverworts nearly absent. Filamentous green algae are common in shallow waterbodies, sometimes covering much as 75%. The number of species averages about 4 (range 1-9) in 16 releves. The TiZZaeetum can be divided into two subassociations: the isoetetosum and the typicum. The isoetetosum is characterized by the presence of Isoetes species penetrating from adjacent deep lake bottoms; it also contains EZatine chilensis, which is more frequent and has a higher cover. The typicum is characterized by the presence (with low cover) of LimoseZZa australis, Pilularia cf. mandoni and/or Isoetes socia. Synecology: The TiZZaeetum is restricted to shallow and submerged habitats on mineral, mostly clayey soils. It occurs I) along shores of deep paramo lakes (isoetetosum), and 2) in ponds or on flat ledges bordering the shore of deep paramo lakes (subassociation typicum). Maximum water depth is about 40 em. The pH of the upper layer of the substrate varied from 4.5 to 6.6. In ponds the pH is about 5, which is considerably lower than in lakes. As may be e~pected, the watertemperature · rises considerably in daytime by insolation.In rel. 161 (Laguna Cuadrada, dry side of the Sierra Nevada del Cocuy at 4050 m), at 4.30 p.m. a temperature of J8°C was recorded for the water containing the subass. typicum, whereas the atmospherical temperature was about 8°C. Copulating paramo frogs (Hyla sp.) were observed in the TiZZaeetum habitat. Mollusca, e.g. Sphaerium Zauricochae Philippi and Gastropoda are common in lake border habitats, which are also rich in aquatic arthropods. Distribution: The TiZZaeetum paludosae is found from the upper subparamo at 3330 m up to the lower limit of the superparamo at 4250 m in the Cordillera Oriental of Colombia. This association and the Isoetetum sociae are altitudinally vicariant communities in the study area (Fig. 91). In lower areas, TiZZaea paludosa was also recorded (as "Elatine triandra") in Scirpus californicus reedswamp of the Laguna de Tota (Boyaca) at 3000 m (Aguirre & Rangel 1976). TiZZaea paludosa was never observed in the superP,iiramo, but EZatine chilensis only once at 4400 m near the sandy shore of a ~uperparamo lake (rel. 323). In the Colombian Cordilfera Central the TiZZa~ etum paludosae has recently been studied from 4150 to 4250 m in the bunchgrass paramo on the Nevado S.Isabel (Cleef et al., in press). In the Venezuelan paramos of the Sierra Nevada de Merida, the TiZZaeetum paludosae has been observed from 3600 and 4250 m. From the Ecuadorian paramos ¢llgaard & Balslev (1979) reported a Crassula-dominated pond vegetation with 1soetes sp. at 3350 m near the Laguna Papallacta (prov. Napo). Weberbauer (1911) describes a rather similar (ot identical) community from a small lake at 4400 m in the Cordillera Negra near Caraz in Peru, where Crassula bonariensis, Isoetes socia and Ranunculus mandonianus (floating leaves) are associated. Ruthsatz (1977)referred to Crassula paludosa (with low cover) associated e.g. with L1:mosella Zineata and EZeocharis acicularis from a dry shallO\v pond at 3600 min the Tucuman Andes, Argentina. Thus, this association appears to be well-represented at least in the northern

And ean paramos of Ecuador, Venezue la and Colombia, and possibly extends further south. 36a .

Subass. isoe t etosum subass. nov. type rel. 485; table 3; Fig. 39

Physiognomy: The bright-greenish (up to 10 em high) closed amphibious herblayer of mainly Ti ZZaea paZudosa is associated with isoetids, e.g., Isoetes species (up to 25 em tall) and the inconspicuous EZatine chiZensis (1- 2 em hi gh). A layer of floating leaves, e.g. of RanuncuZus Zimose ZZoides 路 and AZopecurus aequaZis , may be pre sent also . Composition & syntaxonomy: Dominant species is TiZZaea pa Zudosa (50-100% cover), with EZatine chiZens i s, a tiny aquatic herb with pros ~~ ate stems, as a constant companion (1-15% cover). I soetes paZmeri , or I. ~iaciaZis (1- 25% cover) are differential speci e s . CaZZitr iche sp.(p.), EZeocharis stenocarpa, AZopecurus aequaZis and Ranuncu Zus Zimos eZZoi des have a low frequency. The number of species averages about 4 (range 3-6) in 6 releves. of the Ti ZZaee tum can be easily r ecognized by the differential and the higher presence and cover of EZatine chi Zensis. The the greatest affinity to the subass. typicum of the has also floristic and ecologic properties in common with the Isoetetum paZmeri ; it may be considered intermediate or transitional between the s e aquatic syntaxa.

The isoetetosum Is oetes species isoetetosum has TiZZaeetum , but

Synecology: This subassociation only occurs on gently sloping bottoms in shallow water on the shores of de ep paramo lakes. At 30-50 em depth, a transition is found to the Ditr icho- Isoetion . ~t 3900 m and near rel. 476 a dens e Nil;eUa vegetation associated with Li Zaea subu Zat a, EZeocharis acicuZaris , CaZZi triche sp. was intermixed with the Ti ZZaeetum isoetetosum and the Di t richo- Isoetion . The isoete tosum is generally submerged, but at the end of a long-lasting dry season this community may be partly or completely above water. Substrates vary from sandy- stony to clayey (silty) and peaty; the pH of the water at the lake is 6. I to 6.4. Distribution: The isoetetosum is restricted to the upper subparamo and grass paramo in the Colombian Cordill era Oriental between 3400 and 3900 m. On the Nevado S. Isabel in the Colombian Cordillera Central, this subassociation was studied near the 4150 m level. In the Sierra Nevada de Merida (Venezuela) this vegetation type (impoverished) was found in a lake at the transition from grass paramo into superparamo at 4250 m (rel. 552; Paramo Piedras Blancas). 36b.

Subass. t ypicum subass. nov. type: rel. 41; table 3; Fig. 40

Phys iognomy: Most conspicuous is the closed, bright-greenish Ti ZZaea paludosa-herb layer up to about 10 em high (waterlogged soil or submerged). The ground layer also contains other isoetids, e.g. Isoetes socia, EZat i ne chiZensis , LimoseZZa austr alis, EZeocharis s tenocarpa . A floating layer of leave s of RanuncuZus Zi moseZZoi des and some of AZopecurus aequaZis and CaZZitr iche sp . is common. Composition & syntaxonomy: TiZZaea paZudosa is dominant; Li mose ZZa and PiZuZaPia cf. mandoni are character species of the order, and

austr>a~~路 s

Alopecurus aequalis and Isoetes socia are differential species with low cover (up to 30%); the last- mentioned species only in stands which are transitional to the Isoetetum sociae. Limosella australis is rather rare but if present it covers 10 - 30%. The same is true for Alopecurus aequalis. Pi lularia cf. mandoni is rather inconspicuous, and may be easily overloo.ked. The number of species averages about .4 (range 1-9) in 10 r e leves. The subassociation typicum of the Tillaeetum paludosae is mainly negatively characterized against the isoetetosum by the absence of Isoetes species native to deep paramo lakes. Differential against the isoetetosum is Lilaeopsis schaffneriana, Tillaea paludosa is a differential species against the Isoetetum sociae. Some grass paramos ponds with Isoetes socia may represent a variant. Note: Only few records of Pilularia are available from the Colombian paramos. Lozano et al. (1976) mentioned apparently the same species from th e Paramo de Cruz Verde near Bogota . Pilularia cf. mandoni is here reported from 3330 to 4060 m in the Boyaca paramos. This inconspicuous species may prove to be more common if this kind of habitat of the Tillaeetum is carefully examined throughout th Colombian paramos . The taxonomical position of this Pilularia species remains uncer tain. Synecology: The subass. typicum of the Tillaeetum is found in ponds and shallow small lakes, and as a separate zone on the flat submerged nearshore parts of deeper paramo lakes. In general this vegetation was found on thin mineral (silty-clayey) up to 65 em thickness. Organic matter is rather scarce in these soils. Only in lake-shore habitats the soils are thicker (more than 120 em) and consist of clayey peat and gyttja. In lower regions ooze is commonly present on the Tillaea mat . The pH of the upper soil layer varies from 4.5 to 6.6, depending on the kind of habitat. Pond soils are more acid (4.9 to 5.2) whereas the pH of lake sediments varies from 5.4 to 6.6. The water is not deeper than 30 em; in comparison with the isoetetosum the habitat of the subass. typicum is more often dried out by evaporation. Near the beginning of the wet season the only more or less vital species found is the amphibious Tillaea paludosa, In some places it is accompanied by small Isoetes socia corms which are buried in the top soillayer (rel. 81 & 380 A). Other herbaceous species are supposed to survive as seeds, or as vegetative diaspores from elsewhere. Distribution: This herbaceous amphibian (and amphiphytic) community is common to all paramos of the ColombianCordillera Orientalfrom the upper subparamo at 3300 m up to the superparamo border at 4250 m. Tillaea paludosadominated communities are probably r es tricted to the humid tropfcal Andean paramos. 37.

Communi~ies

of Callitriche and Ranunculus spp.

table 5 a The floristic compos~t~on and plant cover of the Tillaeion seems to change drastically, when the habitat is intensively grazed, trampled and manured by cattle. The tiny, delicate species disappear , e.g . Tillaea paludosa and (to a lesser extent) Elatine cf. chilensis. Generally the cover of Callitriche sp.(p.) and the floating leaves of Ranunculus spp. increases considerably. and so does a dense mass of filamentous green algae. Alopecurus aequalis, a nitrophytic (indicator)plant with floating l eaves, may be present as well. Releves of such communities that are more or less affected by cattle have been listed in table 5?

table 5 a

Callitriche-Ranunculus spp. communities rel. alt. m size m2 soil depth em d.d. locality

616 4100 3 c 50? febr.'80 Isabel Cord. Central

536A 3650 4 cp 25 aug. 1 77 Ghubdula S .Marta

532 3700 3 cp 10-30 aug. '77 Cumbr e S. Marta

560 3815 4 c 10 nov . '78 Almorz. Cord. Oriental

cover â&#x20AC;˘. I Callitriche sp(p.) Ranunculus limoselZoides. 90

Elocharis stenocarpa Lilaeopsis schaffneriana Alopecurus aequalis Isoetes sp. 65 Ditrichum submersum 35 Tillaea paludosa filamentous algae +) or

50 35

~+)

40 I+

<I X

R. spaniophyllus

Localities releve releve 560: Santander; Paramo delAlmorzadero, El Tutal 532: Magdalena; Sierra Nevada de S. Marta, Alto la Cumbre 536A: Magdalena; Sierra Nevada de S. Marta, Laguna Chubdula Volcan S. Isab e l , W slope, El Portal 616: Caldas; Releve 616 is situated at a small lake with the Ditricho-Isoetion, and is regularly trampled by cattle. 38.

Communities with Limosella australis table 6

In several paramos (Sumapaz, Guantiva, Cocuy, Almorzadero) small (up to Limosella australis-dominated patch es in shallow stagnant water were found between 3600 and 4250 m. Rel. 560A & B from a small shallow pond at 3800 m in the Paramo del Almorzadero (El Tutal) offer examples of Limosella australis vegetation: I m2) local

9.7

Table 6

Limos ella australis community rel. no. alt. m depth em soil height em size m2 loc. colorslide Cleef

Limosella australis <'allitriehe sp. Tillaea paludosa Ranuneulus limoselloides

560A 3800 5 clayey 3 I

Almorzadero 3943

560B 3800 3 clayey 5 0.5 Almorzadero 3942

3 5

A Limos ella australis community apparently also occurs submerged in swiftly running water of a small paramo stream surroundec by Mantia fontinalis vegetation near a mire at 3800 m in the Parque Los Nevados, Colombian Cordillera Central (rel. 628). Limosella australis-dominated pond vegetation was observed at about 4 150 m in路 the Parque Los Nevados (Cleef et al., in press) and it is perhaps to newly describe a Limoselletum australis (prov.) on basis of these data. According to Lourteig (1956) Limosella australis is ma inly distributed in the subantarctic zone. Gremmen (1981) mentioned a Limosella australis sociation from the Marian & Prince Edward islands. Recently, however, the Colombian Limosella material collected by the author was recognized by Dr. A. Lourteig as belonging to Limosella australis. Possibly after revision a number of S. Ameri can Limosella specimens will prove to belong to this species.

POTAMETO- MYRIOPHYLLION ELATINOIDES all. nov. (prov.) type: Hydrocotylo ranunculoides - Myriophylletum elatinoides_; table 3 Physiognomy: This aquatic syntaxon predominantly consists of myriophyllids an elodeids. Amphiphytes and isoetids may also be present with low cover. The vegetation mass is denser when the lake is more shallow. Composition & syntaxonomy: Character species are Myriophyllum elationoides (select., transgr.), Potamogeton asplundii (exel.), Hydrocotyle ranunculoides (select/pref.), Potamogeton illinoiensis (pref.) Eleocharis acicularis (pref.) and Scorpidium s_qorpioides (pref.). The number of species is about 7 (4 to 9) in 4 releves. For plantgeographical comments, see under associations, and Cleef (1978). Elodea species (Potamogetonac.)' were never reported for Colombian paramo lakes, but 0llgaard & Balslev (1979) mention ed the genus for an Ecuadorian paramo lake (laguna Micacolha) at 4000 m. Collot (1980) reports Elodea potamogeton up to 4700 min the Bolivian Andes. The Potameto- Myriophyllion has affinities to both the Eleocharitetum macrostachyae (Myriophyllum elatinoides transgr.) and the Isoetetum palmeri. The Potameto-Myriophyllion , however, can be readily distinguished by the high cover of Potampgeton asplundii or Myriophyllum elatinoides. At present the alliance includes one association and two unranked communities, distinguished by the presence either of Scorpidium scorpioides, Potamogeton asplundii,

P. illinoiensis, Lilaeopsis schaffneriana, Isoetes glacialis and Nitella acuminata (both Potamogeton communities), or of Hydrocotyle r anunculoides (Hydrocotylo- Myriophylletum). More releves are reguired to confirm this subdivision. The Myriophyllio- Potamion illinoiensis Rangel & Aguirre (in press) from the Lake Tota at 3000 m in the Andean forest belt is an altitudinal vicariant of the Potameto- Myriophyllion of the paramo belt. Both alliances apparently belong to the Potametea (Tx. & Pr. 1942) Den Hartog & Segal 1964 em. Westhoff 1968, which is widel y distributed in the Holar c tic . Synecology: The Potameto- Myriophyllion is found on shallow lake bottoms (at l eas t to a dep th of 3 m) with stagnant wa t e r and clayey gy ttja-like sediments (Hydrocotylo-MyriophyUetum) or nearly stagnant, slow to swift running water on peaty-clayey to stony substrates (Scorpidium- Potamogeton communities). The pH values of the water (6.6-7.3) indicate mesotrophic t o eutrophic conditions. The habita t probably never becomes dry . The HydrocotyloMyriophylletum plays a major role in the submerged part of the hydroseral s uccess ion on clayey to peat y sediments. Collot (1980) mentions a depth of 1.50- 2.5 0 m for a maximal development of Myriophyllum elatinoides in Lake Titi caca. Flowers of this species were only observed und er these conditions. Distribution: The Potameto- Myriophyllion elatinoides is presently known from the subparamos and th e bamboo paramos proper between 3450 and 3700 m in the southern part of the Colombian Cordillera Oriental. The alliance seems to be present also in paramo lakes of the Cordillera Central from 3300 m up to 4200 m. The Potameto- Myriophyl lion elatinoides is probably wide l y distributed above the uppe r forestline in the tropical Andes. Acco rding t o (Collot, 1980) r e lated communities wi th Potamogeton strictus and Myriophyllum elatinoides were notice d also in Lake Titicac a at 3800 m.

39.

Communities of Potamogeton spp. and Scorpidium scorpioides characteri s tic releves: 29 4 Community of Potamogeton illinoiensis 297 Community of Potamogeton asplundii table 3; Figs. 41 (also Fi gs. 43, 50, 51)

Physiognomically, two herb layers can be recognized in these elodeiddominated communities; I) an isoetid l ayer of Isoetes glaciali s and Eleocharis acicularis; and 2) a sligthly stratified uppper layer of elodeids (Potamogeton, Myriophy llum ) and bryo phy tes (Scorpidium) r eaching the surface of the water. Communities with Scorpidium and Potamogeton were only studied in the Laguna La Guitarra (Me ta), at 3425 m and 6 km NH of the Nevada de Sumapaz. Along its marshy shores are stands with Potamogeton asplundii. The swiftly running water of th e outlet of this lake cont a ins Potamogeton illinoiensis. Accord ing to Dr . L.B. Holm-Ni e lsen (in litt . ) Potamogeton illinoiensis is wid e l y distribut ed in tropical America from the s outhern United St a tes to South Brazil; the as yet unde scr i bed Potamogeton asplundii is only known from Ecuadorian and Colombian paramos . The presence of different Potamogeton species is th e main floristical difference be tween the two elodeid communiti es, whi ch have many species in common ,e.g. Scorpidium scorpioides , Myriophyllum elatinoides, Isoetes glacialis, Lilaeopsis schaffneriana and Ekoeharis acicularis. Nitella acuminata and Isoetes glacialis are invading from the deeper lake bottom, whereas amphibian species, e . g . Tillaea paludosa and

Elatine chilensis, are found closer to the shore. Fewer species are present in rel. 194 with Pot amogeton illinoiensis, probably as a result of the strong current. Note: Scorpidium scorpioides is considered as the only Scorpidium species in the cool aquatic habitats of the tropical high Andes. Specimens (5943, 5946), almost similar to those described by Herzog (1916) as Scor pidium t ur fa ceum, were collected during the field work in the Colombian paramos (det. Dr. P.A. Florschutz). The differences with the holarctic Scorpidium scorpidioides are too weak, however, to consider the tropical Andean material as a separate species (Dr. D. Griffin III, pers. comm . ). The habitat of the two Potamogeton communities is quite different. Po t amogeton i llinoiensis vegetation covers the solid sandy to gravelly shallow bottom ne ar the outlet of this moraine-damned lake. Potamogeton asplundii is pre dominantly found on clayey to peaty substrates and on gy ttja. The pH values fi . 6 and 7.2 by the water indi cate eutrophic conditions. Leeches (Hirudinae) have been commonly observed. Data on the distribution of the two Potamoge ton species in the Colombian Andes are mainly based on our plant specimens identified by Dr. L.B. HolmNielsen (AAU). Both Potamogeton communities might be expected at least in the corresponding paramos and extending in the high Andes of Ecuador and other parts of the tropical Andes. Potamogeton i llinoi ensis is known from lakes in the Colombian Cordillera Oriental, .from the high plain of Bogota (2600 m) up to the grass paramo (3800 m): Laguna de Fuquene, Laguna de Tota, Laguna La Guitarra (Paramo de Sumapaz) and Laguna El Alcohol (Paramo de Guantiva). In Colombia, Potamoge ton asplundi i was only collected from 3300 to 3800 m from the upper forest line to the bamboo paramos of the Cordillera Central (Purace) and the Cordillera Oriental (Sumapaz, Cuantiva). Because of the small number of releves no syntaxonomical rank was given to these Potamogeton -communities. Scorpidium scorpidoides , I s oetes glacialis and Liliaeopsis schaffneriana are not pr e sent in the Hydr ocoty lo- Myriophylletum . 40.

Hydrocotylo r anuncu l oides - Myriophylletum elatinoi des ass. nov. t ype: rel . 266; table 3; Fig. 42 (also Fig. 49) Physiognomy:

Te weaky stratified herb layer mainly consists of dense

Myr iophyllum elationoides, which may be partly emergent. The foliage of Hy drocotyle r anunculoides is morphologically different when submerged or emerged. Elatine chilensis is found in a distinct ground layer partly covering the ~e aty

and muddy substrate.

" Composition & syntaxonomy: The dominant and sele'c tive character spec i e s (trans gr.) is Myriophy llum elatinoides, as a rule accompanied by some other vascular species, as Hydrocotyle ranunculoides (preÂŁ.), Elatine chilensis (fue h~her cover (5-15%) is differential agains t the communities with Scorpidium and Potamogeton species) and Eleochari s acicularis. Mosses are practically absent. The number of s pecies in 2 releves is 4 and 8 respectively. Th e Hydr ocotylo- Myr iophylletum is strongest related to the ScorpidiumPotamogeton communities and loca l l y to the I soetetum palmeri in the paramo belt. Synecology :

The association is reported from thick muddy and peaty

\00

substrates in stagnant water in paramo lakes , where the HydrocotyloMyriophyZZetum is the first truely aquatic vegetation near the shores. Water depths vary from shallow to about 50 ern. The pH of the water is 6.5-7.3. ft1yriophyZZum sterns are rather l ong and it is believed that the habitat of the Hydrocotylo- Myriophylletum experiences considerable changes in water level, but apparently it is never completely above the water-line. Leeches and frogs were noticed. Migrating aquatic birds (e.g. ducks) must have a strong influence on this vegetation by foraging and manuring , and are regarded as the principal agens responsible for the present wide distribution of the composing vascular taxa. Distribution: The Hydrocotylo- Myriophylletum elatinoides is only known from the mainly bamboo-dominated upper subpararno and the lower grass pararno in the southern part of the Cordillera Oriental . The association is reported from the Laguna La Primavera (3550 rn.) near the Nevada de Surnapaz and from the Laguna Seca (3650 rn) in the upper Rio Chuza valley, East of Bogota. This syntaxon may perhaps be found up to about 4000 rn. This association is supposed to be widely distributed in the Andes, as both Myriophyllum elatinoides and Hydrocotyle ranunculoides are common in the rnoutains of Latin America. Myriophylium elatinoides is also known from the Islas Malvinas and Australia - Tasmania. The highest known Andean locations are the Laguna Aguascocha and the L. Caprichosa at 4750 rn in Peru. In the Colombian Andes, this species is found from 2700 rn to 4000 rn. In the Colombian Andes Hydrocotyle ranunculoides is present in the subandean forest belt up to 4000 rn.

JUNCO ECUADORIENSIS- ELEOCHARITION MACROSTACHYAE all. nov. type: Eleochariteturn macrostachyae; table 3 Physiognomy: The alliance consists of hydroseral reedswarnp communities are structured in three layers : I) an open isoetid ground layer (consisting of Elatine chilensis, Tillaea paludosa and Isoetes spp.), 2) an aquatic moss-herb layer reaching up to the water surface and consisting of Sphagnum spp., Drepanocladus spp., Myriophyllum elatinoides, Callitriche sp. and occasionally dense filamentous algae; floating foliage of Ranunculus limoselloides, and 3) a 50 ern high fieldlayer of the helophytes Eleocharis macrostachya and

Juncus ecuadoreinsis. Composition & syntaxonorny: Exclusive character species are Eleocharis macrostachya and Juncus ecuadoriensis, and also the purplish algae cf. Microspora sp. and/or Zygnema sp. probably are selective character species. Ranunculus Zimselloides, Elatine chilensis, Tillaea paludosa, Myriophyllum elatinoides, Drepanocladus exannulatus (and to a lesser extent, Sphagnum cuspida tum and Calliergonella cuspidata) are differential by presence or their higher cover. The average number of species is 5 - 6 in 9 releves . Physiognomically and ecologically, the Junco-Eleocharition macrostachyae has the greatest affinity with the Phragmitetea R. Tx . & Pr. 1942. On the basis of the predominant species in the field layer, the alliance can be subdivided into two associations: the Eleocharitetum macrostachyae (41) and the Elatino- Juncetum ecuadoriensis (42) . Synecology: The Junco-Eleocharition occurs in shallow hydroseral habitats on silty to clayey and peaty soil:

JOJ

I) along shores of deep pararno lakes (Eleocharitetum macrostachyae

myriophylletosum ), 2) in ponds (mostly Eleocharitetum macrostachyae tillaeetosum ), and 3) in pools (Elatino-Juncetum ecuadoriensis) . The pH values vary from 6.3-7 .4 in e utrophic large pararno lakes in acid pools. Just as discussed for the Tillaeion , the water temperatures may, rise in day-time by insolation. The depth of the water is SO ern or slightly mor e. Distribution: The Junco-Eleochari tion macrostachyae is widely distribut ed in the lower part of the pararno belt of the Colombian Cordillera Oriental from 3400 rn to 3900 rn. The a lli anc e, especially the Eleocharitetum macrostachyae, seems to extend into the Andean forest belt to a height of 2700 rn. Since both predominant and exc lu路sive char acter species are common in the pararnos of the Colombian Cordillera Central of Ecuador, the JuncoEleochari tion may be expected in most of the northern Andean pararnos. 41.

Eleocharitetum macrostachyae ass. nov . t ype : rel. 300; tabl e 3; Fig. 43 & 44

Physiognomy: The Eleocharitetum macros tachyae dominated, cyperaceous reed swamp, sometimes falling Thi s association is stra tified in: I) an open ground layer, which may consi st of scarce sec t. Laeves , Elatine chilensis, Tillaea paludosa

is a by sometimes helophyt es dry in the dry season. spec imens of Isoetes and Eleocharis

s tenocarpa; 2) a herb-moss layer up to the wa ter surface of Myriophyllum elatinoides, Callitriche sp., aquatic: oosses and occasionally Utricularia obtusa with a t or just above the waterlevel Ranunculus limoselloides and Lilaeopsis schaffneriana; and 3) a field laye r (about 40- SO ern high) with a conspicuous r eddish-orange hue of Eleocharis macrostachya -sterns, loca lly with Juncus . ecuadoriensis . Composition & syntaxonorny: An exclusive character s peci es is Eleocharis macrostachya, a differential species is the moss Calliergonella cuspidata . Myriophyllum elatinoides is differential for the myr iophylletosum and Tillaea paludosa, Callitriche sp., Elatine chilensis and Ranunculus limoselloides are differenti a l for the tillaeeto3um. Dif feren ti a l against the Elatino- Juncetum ecuadoriensis are Tillaea paludosa (up to 20 %), Callitriche sp(p.) (up to IS%), Myriophyllum elatinoides (up to 40%) and Calliergonella cuspidata (up to 80%). Differential against the PotametoMyriophyllion prov.are Tillaea paludosa, Callitriche sp., Ranunculus limoselloides and Calliergonella cuspidata . The tillaeetosum mainly differs from the Tillaeetum paludosae (36) by the presence of Ele9charis macrostachya and Juncus ecuadoriensis the Tillaea cover is low (up to IS%) compared to the predominance in the Tillaeetum paludosae. The average number of species is 6 (2-11) in 9 rel eves . Synecology : This associa tion of shallow wa t er i s locally present as a reedswarnp along the shores of paramo lakes. Larger pat ches of the Eleocharitetum macrostachyae may indicat e a transition of open wa t er vegeta tion t o land vegetation, e.g. communities of the MarchantioEpilobietalia. Eleocharis macrostachya vegeta tion also may cover smal l l akes or ponds with practically stagnant water. This specie s i s generally foun d on organic c l ayey l ake sediments. Colonization begins on sof t mud; towards the shor e the Eleochari s rhizomes grow in a dense mat, thus contributing to soil

J02

solidity. In zones with a stable water supply peat formation is uninterrupted and simultaneously, clayey particles are trapped. The pH of the substrate is 6.3-6.5, that of the lake water 4.9-7.4. The tillaeetosum in smaller shallow lakes with stagnant water is richer in vascular species than the myriophylletosum, which forms a reedswamp zone in lar ge r and deeper paramo lakes. Towards open water, wave action, increasing depth and lesser lighi intensity are limiting factors for the myriophylletosum. During th e dry season (part of) the Eleocharitetum macrostachyae is exposed. In the smaller lakes with the tillaeetosum the water evaporates more rapidly than in deeper lakes, and the tillaeetosum is emerged for a longer period of the year. This explains the higher frequency and cover of hel ophytes and amphiphytes. True hydrophytes (e.g . Myriophyllum elatinoides) are practically absent. In the transitional zone from the open water to the marshy shore, the myriophylletosum is replaced by the tillaeetosum of the Eleocharitetum macrostachyae 路(f or example, see rel. 300). The shallow water of the . Eleocharitetum macrostachyae, especially the tillaeetosum, contains a rich fauna of small aquatic insects, lee ches and Gastropoda (cf. Planorbis.), and paramo frogs have been noticed. If the water level falls considerably, the Eleochariteum macrostachyae becomes accessible for foraging Cavia porcellus. Distribution: The Eleocharitetum macrostachuae is distributed in the paramos of the Colombian Cordillera Oriental from the ~pper supparamo at 3300 m up to the lower grass paramo at 3900 m on the dry W side of the Sierra Nevada del Cocuy. The Eleocharitetum macrostachyae might extend as far down as 2700 m, where similar reedswamp was observed in a small lake in the Andean Quercus forest nearS. Cayetano (Cundinamarca). According to data from floras and herbaria, Eleocharis macrostachya is distributed from the southern Unites States to Argentina. Note: Rel. 184 and l ater 498A were made at the location of the palynological section "VL VII", Sierra Nevada del Cocuy, published and illustrated (photo 3)by Gonzalez et al. (1965). Releve 498A represents the strongh reduced plant cover near the end of the extremely long dry season in the beginning of 1977. 41a. Subass. myriophylletosum elatinoides subass. nov. type: rel. 11; table 3; Fig . 43 Physiognomy: See the association. The groundlayer, however, is dominated by Myriophyllum elationoides. Composition & syntaxonomy: This subassociation is characterized by the presence of Myriophyllum elatinoides (cover up to 40 %). The average number of species is 4 (2 to 6) in 4 releves . In general, the number of species is less than in the tillaeetosum. The presence of Myriophyllum elatinoides and the absence of Tillaea paludosa, Elatine chilensis, Ca~litriche sp., Lilaeopsis schaffneriana and Ranunculus limoselloides are differential against the tillaeetosum. Some records of a higher cover (80%) of both Ranunculus limoselloides and Calliergonella cuspidata mark the transition from open water to mossy marsh and might be ranked at the variant level. Synecology: See also under association. In the eutrophic paramo lakes the pH of the toplayer of the substrate ranges from 6.3 to 6.5; the pH of the

103 lake water is 7 . 4. High cover of Calliergonella cuspidata apparently causes a lesser cover of Eleocharis macrostachya and finally this moss species dominates . The nutrient content must be high in the myriophylletosum , as suggested by the high pH (and the abundance of young trouts) . Distribution : This subassociation was only observed in the Laguna La Guitarra at 3425 m near the Nevada de Sumapaz. 4lb . Subass. tillaeetosum paludosae subass. nov. type: rel . 184; table 3; Fig. 43 & 44 Physiognomy: In contrast to the myriophylletosum amphiphytes (Elatine chilensis, Tillaea paludosa, Ranunculus limoselloides) dominate in the ground layer. The helophyte Juncus ecuadoriensis is found together with Eleocharis macrostachya in the upper stratum. Composition & syntaxonomy: The tillaeetosum contains about twice as many vascular species as the myriophylletosum, with Tillaea paludosa .

Ranunculus limoselloides, Elatine chilensis, Lilaeopsis schaffneriana, Callitriche sp(p . ) and Juncus ecuadoriensis . For differential species , see also the association and the myriophylletosum. The tillaeetosum is differentiated from the Elatino-Juncetum by the presence of Tillaea paludosa and Eleocharis macrostachya. There are numerous mosaic-like patterns in the transition to the Elatino-Juncetum ecuadoriensis and to the myriophylletosum (of this association) , which is reflected in some not fully homogeneous releves . The average number of species is 8 (range 6-11) in 5 releves . Utricularia obtusa and Drepanocladus revolvens are occasionally present with a high cover . Synecology: The pH range of the water is 4.9 to 7.4 . This subassociation occupies a specific kind of habitat : I) near the shores of large mesotrophic to eutrophic paramo lakes,and 2) in small lakes with mainly mineral bottoms with oligotrophic to mesotrophic conditions . Environmental conditions seem to be favourable for insect life (see assoc.) . Water temperatures are high in daytime: e.g . 17째 at noon on Hay 3, 1973, in rel. 404 at 3700 m. Such . high temperatures of the lakes may explain why the tillaeetosum is found at greater heights than the myriophylletosum. For further details, see association . Distribution: The tillaeetosum paludosae is found throughout the Cordillera Oriental from the upper subparamo at 3450 m to the grass paramo proper at 3900 m on the dry side of the Sierra Nevada del Cocuy .

42 .

Elatino chilensis- Juncetum ecuadoriensis ass. nov . type: rel. 67; table 3 ; Fig. 71

Physiognomy : This association can be easily distinguished as patches of green to brown-reddish reed swamp . The structure of the Elatino-Juncetum ecuadoriensis is more or less similar to that of the Eleocharitetum macrostachyae. The submerged open ground layer contains Isoetes spp . , Elatine chilensis, and rosettes of Ranunculus limoselloides . Sphagnum cuspidatum and Drepanocladus exannulatus may be floating . The characteristic small ellipsoid leaves of Ranunculus limoselloides are spread out on the water surface between the upper open stratum of the 20-30 em high leaves , flowers and fruiting parts of the helophytic Juncus ecuadoriensis .

104

Composition & syntaxonomy : In the E~atino-Juncetum ecuadoriensis , either Juncus ecuadoriensis or Elatine chilensis may be dominant, each covering up to 80% . Ranunculus limo s elloides is usually pres ent (cover up to 30%) and compl ete ly submerged Sphagnum cuspidatum may be common, generally with low cover. Depending on size and depth of the waterbody, Isoetes palmeri and I . cf. socia may be present. Dr epanocZ.adus exannulatus locally attains a cover of up to 80%. Dense masses of characteristic violet-purple filamentous Chlorophyta (e.g. Microspora spp., Zygnema spp.) replace Drepanocladus

exannulatus . The ave r age number of species is 4-5 (4-6 species in 7 releves). Juncus ecuadoriensis i s a tr ans grediant selective char ac ter species; Elatine chilensis and Ranunculus Umoselloides are preferential character speci es . The Elatino- Juncetum ecuadoriensis shows close affinities to the other assoc iations of the Junco- Eleochar ition macrostachyae, and to the two variants of the Isoetetum palmer i with Sphagnum cuspidatum (34ab) and Drepanoc~adus exannulatus (34aa). Differential against the Eleocharitetum macrostachyae are Sphagnum cuspidatum and Drepanocladus exannulatuR and,with a highe r cover, Juncus ecuadoriensis and E~atine chi~ensiR. Differential is also th e absence of E~eocharis macrostachya. Drepanoc~adus exannu~ atus and filam entous algae, e.g. Microspora and Zygnema spp. may be 路present in the E~atino-Juncetum, but absent a r e such species as Ti~~aea pa~udosa, Ca~~itriche sp ., Sphagnum cyc~ophy~~um, Dr epanocladus revolvens and other species belonging to th e Wernerietea. In the E~atino-Juncetum, Sphagnum cuspidatum never becomes dominant,as in th e floating Sphagnum cuspidatum community with Juncus . The Elatino-Juncetum ecuadoriensis is provisionally subdivided into two var iants路, one with Drepanocladus exannulatus , and the other with purplish algae (Microspor a/Zygnema) . Additional releves and observations in other paramos are required to confirm thi s subdivision. mainly found in pools in the Syruocology: The Elatino- Juncetum is lar ge Sphagnum bogs or as a zone in larger paramo lakes, which are partly fill ed up with peat(Sphagnum cuspidatum ). Both releves containing I soetes cf . socia originate from ponds with clayey-silty bottom. In general, this sediment is thin, wher eas the peat layer below may be much thicker (at least 2-4m). The pH of the wat er in these oligotrophic pools is 4 .6 to 5.0 . In rel. 67 the pH of the soil is 4.8 to 5.2. The water is not deeper than 50 em. Juncus ecuadoriensis was often found to be rooting in the dense floating mass of either Drepanocladus exannu latus or filamentous algae . Such a floating carpet of a l gae causes poor, photosynthetic conditions for mosses and vascular plants, unle ss they have their leaves on top or above the algae mat. Drepanocladus exannulatus is absent and the cover of Sphagnum cuspidatum and Ranunculus limoselloides is low. The thick coherent mass of algae prevents th e floating leave s and flowers of Ranunculus limose lloides to r each the surface. On the other hand, the helophyte Juncus ecuadoriensis r eaches its highest cover (80%) in stands with a well-developed layer of algae. This species sticks it leaves through it. The pond vegetation with Isoetes c f. socia has been studied a t the end of the extremely long dry season of 1977. Th e stand was compl e tely dried out, and Elatine chilensis was dying or decaying . Sphagnum cuspidatum and Drepanocladus exannulatus were not present in this stand. Distribution: The Elatino - Juncetum ecuadoriensis is known from the lower paramos in the Colombian Cordillera Oriental; from the upper subparamo at 3450 m up to the grass paramo at nearly 3900 m (on the dry s ide of the Sierra Nevada del Cocuy). As the predominant species have a much wider distribution, at least in the tropi cal Andes, this association may be

] 05

expected in other areas, e.g. Ln the Ecuadorian paramos, from where Juncus has been described.

RHEOPHYTIC COMMUNITIES The type of submerged plant community in cold running paramo waters largely depends on the altitude and on the substrate. The PhiZonoto-Isotachidetum serruZatae is found on gravelly ani stony streambeds between 3700 and 4350 m. In lower areas this liverwort community is replaced by the moss community Dendrocryphaeo-PZatyhypnidietum. At present, both these 路r heophytiCi, bryophyllous associations have only been studied in the northern high paramos of the study area and in the Colombian Cordillera Central (Cleef et al., in press). The Dendrocryphaeo-PZatyhypnidietum and related communities extend far down into the Andean forest belt to about 2000 m. In about I m deep running water on sandy to loamy soil in the Rio Lagunillas at 3900 m in the Sierra Nevada del Cocuy, a distinct isoetid community was observed, consisting only of Isoetes novo- granadensis (sect. Terrestres) and covering less than 10%. The same community was observed in a similar habitat at 3800 min the headwaters of the Q. Minas, NW of Belen (Boyaca). According to Fuchs (198JC) the species is only known from the northern Andean paramos (Venezuela to Ecuador). In the Cordillera Oriental and Central of Cblombia this species is reported from the subparamo and grass paramo from 3300 to 3900 m in various aquatic habitats, e.g. streams, lake shores, rv'erneria pygmaea flush,and h alf emergeq in mires. Submerged pure stands of MyriophyZZum eZatinoides are present in paramo streams with sandy to gravelly beds, 30 to 150 em deep, at 3900 m. In a small stream draining a steep moraine slope at 4250 m in the Bocatoma valley (Sierra Nevada del Cocuy), the rare semi- aquatic moss Andreaea nitida was collected by Dr. P.A. Florschutz. The same species was collected by us at 3700 m in the Fila Sitiales, Paramo d~ Sumapaz, and in the superparamo of thevolcano Ruiz (Colombian Cordillera Central) at 4250 m. The species was found in the dry bed of a streamlet, together with Racomitrium dicheZymoides . The last species then was only known from its type locality in an Andean forest stream above Bogota at 2800 m; and was recently collected also from a stream at 3150 min the Paramo de Guasca (Dr. S.R. Gradstein, pers. carom.). Small paramo streams often partly hidden in bogs and alluvial sediments mainly have peaty to clayey beds. At heights from 3300 to 3700 m, a distinct community was observed of Potamogeton drepanocZadoides and FontinaZis bogotensis . Other species are: LiZaea subuZata, LiZaeopsis schaffneriana, Isoetes bischZerae, I. kiZZipii(occasionally) and DrepanocZadus revoZvens Isoetes bischZerae was collected in the upper subparamo (3300-3600 m). FontinaZis bogotensis was first described from an Andean forest stream near Bogota, an is present only known from streams and a paramo lake at 3700 m in the Colombian CordilleraOriental. Potamogeton drepanocZadoides is only known from paramo streams in northern Peru, Ecuador and Colombia (Dr. 1. HolmNielsen, in litt.)

106

43.

PhiZonoto- Isotachidetum serruZatae ass. nov. type: rel. 454; table 7; Fig . 45 & 55

Physiognomy: This submerged rheophytic bryophyllous communit.y consist of a dense mat of conspicuous reddish liverworts up to 5 em high, with a cover from 60 to 100% . Table 7

PhiZonoto - Isotachidetum serruZotae ass. nov.

rel.nr. alt.m. water deEth em

Isotachis serruZata Chlorophyceae

CaZZitriche PhiZonotis andina

451 454 462 475 493 487 488 477c 4335 4315 4350 4085 3865 3875 3875 4070 30 5-35 10 10-40 3- 5 20 40 75 I+

â&#x20AC;˘

75 5

100

Composition & syntaxonomy: The dominant species is the liverwort Isotachis serruZata. Gradstein et al. (1977) discussed the taxonomic position, morphology, distribution and ecology of this polymorphic tropical Andean species. In one place PhiZonotis andina has been found associated with a species of CaZZitriche. Filamentous algae may locally be common. Stands of the rare Isotachis Zacustris were present in the Parque Los Nevados in the Colombian Cordillera Central,(Dr. S.R. Gradstein, pers. comm.); the species is expected in this association in the study area. The.mean number of species is 1-2 in 8 releves. Isotachis serruZata is a selective character species and I. Zacustris, and PhiZonotis andina are preferential character species. The PhiZonotoIsotachidetum serruZatae has a contain affinity to the Ditricho- Isoetion in the high paramo lakes, and also to the high altitude Carici peucophiZaeWernerietum crassae in the large and wet or boggy glacial depressions between lower superparamo moraines in the Paramo Concave, Sierra Nevada del Cocuy. This association is altitudinally vicariant with the Dendrocryphaeo-

PZatyhypnidietum riparioides. Synecology: The PhiZonoto-Isotachidetum is found in shallow , cold and clear streams rich in oxygen, and mainly in swiftly running water. The submerged Isotachis serruZata mats usually grow on large stones (Fig. 45), but th ey also occur on top of clayey-silty to coarse sandy sediments. The pH of the water in streams on t?e high Cocuy paramos is 5.0 to 5.5. The water of the small stream in rel. 454> at 4315 m was frozen in the early mornings (February 26- 28, 1973) after temperatures of -5Â°C at night. In releve 451 at 4335 m, many small black leeches (Hirudiinae) were present on the clayey and stony soil between the Isotachis stems. Distribution: The PhiZonoto-Isotachidetum serruZatae is distributed in the Colombian Cordillera Oriental from 3850 to 4350 m, from the upper grass paramo up into the superparamo. This association is known from the upper reaches of the Sierra Nevada del Cocuy (Arauca, Boyaca); it is also reported for the Parque Los Nevados (Cordillera Central) and is likely to be found in other high mountains of tropical America. Submerged plants of Isotachis serruZata have been collected in a small stream at 3850 m on the southern slope of the Paramo del Almorzadero (Santander), at 3730 min the Paramo de la Rusia, and at 4000 m in the Parque Los Nevados, Colombian Cordillera Central.

107

44.

Dendrocryphaeo latifoliae - Platyhypnidietum riparioides type: rel. 1A; table 8 Cleef & Gradstein ass. nov.

Physiognomy & synecology: The single low pleurocarpous ground layer of this rheophytic community covers submerged stones in shallow river beds; stands are common in rapidly moving water, rich in oxygen. The Dendrocryphaeo- Platyhypnidietum is apparently altitudinally vicariant with the Philonoto- Isotachidetum serruZatae, known from similar habitats in running water on the higher paramo. Composition & syntxonomy: Dominant, a lmost single and exclusive character species is the moss Platyhypnidium riparioides, a wide temperate spec i es . Riccardia sp. (1032), Racomitrium sp. (Gradstein & Aguirre 3665a), Grimmia alpicola var. rivularis and a new species of the austral-antarctic genus Dendrocryphaea (D. latifolia) have been observed once each. table 8

Dendrocryphaeo latifoliae - Platyhypnidietum riparioides Cleef & Gradstein ass. nov.

rel. nr. rel. area: 1-4 m2 alt. m

Platyhypnidium riparioides algae

Dendrocryphaea latifolia Riccardia sp. Grimmia alpicola var. rivularis Racomitrium sp. (Gradstein 3665a)

13A

17A

6A 300A

607

638

3400 3500 3635 3450 3300 3675 3320 60 x 5

Localities & botanical coll ec tions: 1A Paramo de Sumapaz : Chisaca,Quebrada S. Rosa. in Polylepis quadrijuga forest (Cleef 220: Gradstein 3664, 3665, 3665a, 3665b); 13A Paramo de Sumapaz: Q. Sitiales. (Cleef 1032, 1033); 17A Paramo de Sumapaz: C. Nevado. (Cleef 1228) ; 6A Paramo de Sumapaz: Laguna La Guitarra, stream ending in the lake. (Cleef 8 74); 300A Paramo de Sumapaz: Rio Nevada. (Cleef 8302); 607 Volcan Otfin (Cord. Central): Q. La Sierra; 638 Rio Totarito (Cord. Centril). Distribution: Platyhypnidium riparioides is reported for tropical America from the Andes, Brazil and Costa Rica. In Costa Rica and the northern Andes its lowermost habitat is 2000 m (D. Griffin, pers. comm.) . In the Colombian Cordillera Oriental and Cordillera Central, this moss community was studied from 3700 m in the lower paramos down to the Andean forest belt at 3000 m, especial l y the Paramo de Su~apaz and the paramos of Risaralda and To lima. Other aquatic communities 45.

Community of Eleocharis acicularis table 9; Fig. 46; lit. Ruthsatz 1977

Physiognomy: This community hardly shows any stratification and consists of an open submerged Eleocharis layer . Characteristically, the long rows of Eleochar1:s stolons grow in an irregular criss-cross pattern. Mosses and algae are floating.

108

Composition & syntaxonomy: The only vascular species is EZeoeharis acieuZaris; it is accompanied by DrepanoeZadus sp. or Sphagnum euspidatum, and by violet-greenish filamentous algae (mostly Mougeotia spp.) No s yntaxonomical rank has been assigned to this community.On basis of the available data it cannot be properly differentiated against other (holarctic) communities with EZeoeharis acieuZaris. Note: Apparently, this is the first mention of EZeoeharis aeieuZaris for the Colombian Andes . The species has been collected in many places by the present author between 3400 and 3850 m in the Cordillera Oriental. table 9

Community of EZeoeharis aeicuZaris

rel. nr. rel. area m2 water depth em substrate depth em pH (~ater) alt. m locality

194 145 240 143A 1 1 1 4 20 30 25 35 gyttja gyttja gyttja gyttja ~120 ;>120 ;>120 ~120 4.8% 4.7 5.8 3690 3625 3845 3550 Rusia Chisaca Chisaca Neusa

EZeoeharis aeieuZaris Algae (Mougeotia sp.) DrepanoeZadus sp. Seha~num

20 1

20 3 60

cuseidatum

5 5

30 1

Synecology: Small shallow (20-35 em), slowly drained pools in Sphagnum bogs of the grass paramo. The bottom of the pools consists of decayed peat of some meters thick. Probably, sites at which this community is found, never become dry. Stagnant water is always present in the habitat. The pH of the water is 4.7-5.8. Distribution: The EZeocharis acicuZaris community is sparsely distributed in the lower bunchgrass and bamboo paramo propeL of the Cordillera Oriental between 3550 and 3850 m. Its upper limit is probably correlated 路with that of Sphagnum bogs. Below 3550 m EZeocharis aeieuZaris might be expected in pools in open Sphagnum bogs. This community is probably also present in other open Sphagnum bogs high in the tropical Andes . Ruthsatz (1977) reported the presence of EZeoeharis aeieuZaris from the northern Andes in Argentina between 3500 and 3800 m. The species was observed in the deepest part of ~hallow puna lakes, and was associated with MarsiZia punae De la Sota, KardamogZyphos nana Schldl. {Cruc.), PZagiobotrys eongestus (Wedd.) I.M. Johnston (Borag .), DistiehZis humiZis Phil. (Gram.) and BouteZoua simplex Lach. (Gram.). 46.

Community of Equisetum bogotense table 10; Fig. 64

Physiognomy: The open herb layer dominated by Equisetum bogotense is about 25 em high. The community in the Rfo Lagunillas(Sierra Nevada del Cocuy) was rheophytic and practically submerged with the Equisetum stems bending with the current. Composition & syntaxonomy: Equitesum bogotense is the only vascular plant in the two paramo releves. This community has not been ranked phytosociologically, because of the low record of releves and observations.

J09

tabl e 10

Community of Equisetum bogotense

148 rel. nr. I rel. area m2 250 total size stand m2 20 water depth em gyttja soil pH substrate (root zone) 5.8 water current 3730 alt. m Chuza locality

Equis etum bogotense f ilamentous green algae cf . Microspora sp.

486 2

1-50 stony-clayey +

3890 Cocuy

75 10

Synecology: Equi s etum bogotense-dominated stands are apparently present in different habitats: on lake gyttja in pools and in stony stream. beds. In the former the s pecies is surrounded by Plantago r igida and Or eobolus cushion bog. At 3450 m, near t~Nevado de Sumapaz, an Equisetum bogotense stand was observed on a calcareous mire. Near Inza (Cauca), at 2700 min the Andean f orest belt of the Colombian Cordillera Central, an Equisetum bogotense community was examined on wet rocks; apart from E. bogotense it contained Marchanti a plicata, Anomobr yum fi l iforme , Philono t is sphaerocarpa and Cor a 7JaVonia . Equisetum bogo-tense apparently is an euryoicous species, locally dominant in wet roadside trenches in the upper andean forest as well as in the lower paramo. Distribution:

Herbarium data and additional observations indicate that

Equisetum bogotense is widely distributed between 1500 and 4000 m in the tropical Andes and on the Galapagos Islands 47.

(Vares chi 1970)

Lemno - Azolletum f i l i cu loides (Br.Bl. 1952 p.p.) Segal 1965 lit.: Cleef et al., in press; Aguirre & Rangel 1976.

The present distribution of this pleustophytic wide-temperate community in our area is between 2000 m (Laguna Pedro Palo) and 3700 m (Lagunas de Chisaca). The communities floating on grass paramo lakes contain few associated species, and merely consist of a low, dark reddish layer of Azolla plants. Lemna mi nor was found as an associated species up to 3300 m. The Lemno - Azolletum is also present up to 3900 m in the grass paramo of the Colombian Cordillera Central (Cleef et al., in press.) and was reported by 0llgaard & Balslev (1979) from the volcano Antisana, Ecuador, at 4000-4150 m. Aguirre & Rangel (1976) provided phy tosociological data on the Lemno Azolletum from Lake Tota at 3000 m. Lemna minor, Wolffia columbiana Karst. and Ricciocarpus natans were reported as common associates. Finally, Azolla f iliculoides is present also in other pleustophytic commun1t1es in warm tropical lowland fresh water bodies (Cleef & Idrobo, in prep.)

110

REEDSWAMPS & MIRES

Marchantio - Epilobietalia order nov. type: calamagrostion ligulatae (this study); table

Physiognomy: The cyperaceous reedswamps and grass mires of the paramo generally show two layers: I) a high cyperoid of graminoid field layer; and 2) a low herbaceous or bryophytic ground l ayer. A third shrubby upper layer is locally developed (e.g. Senecionetwn reissiani, Ludwigia peruviana - Carex acutata community. Composition & syntaxonomy: Character species are Marchantia plicata (excl.), Epilobiwn denticulatwn and E. meridense (excl.), Ranunculus flageZZiformis (select.?), Senecio subruncinnatus (select.), Cardamine africana (pref.?),Cardamine bonariensis ( se l.), Lachemilla fulvescens (excl.), Eleocharis stenocarpa (pref.?) and Breutelia inclinata (select.) in combination with the character species of the alliances and lower ranked syntaxa, as

Senecio reissianus, Carex pichinchenBis, Valeriana plantaginea, Carex acutata, Carex jamesonii, Cyperus rivularis, Ga l ium trianae, Gratiola peruviana, Symphyogyna sinuata, Mimulus glabratus, Lupinus alopecuroides, Calceolaria mexicana, Lupinus cf. verjonensis, Draba sp. (white petals), Stachys elliptiaa Geranium confertwn, Bryum laevigatum, Drepanocladus aduncus, Calamagrostis ligulata, Cerastium imbricatwn, Mantia fontana, Mantia aff. meridensis and Plantago australis ssp. oreades . The Marchantio-Epilobietalia contain a number of conspicuous vascular superparamo elements, which grow . in the cold and wet paramo reedswamps, mires and bogs and are morphologically different from the (presently,a lso isolated) superparamo population. Taxa to be mentioned in this respect are Valeriana plantaginea, Senecio canescens, Lupinus alopecuroides, Draba sp. ~64a- white petals), Senecio niveo- aureus, Mantia cf. meridensis and Cerastium imbricatum. Specific comments on these species are given in following descriptions of the paramo swamp and mire vegetation. The order comprises nearly all Carex and Cyperus reedswamps and Calamagrostis ligulata mire communities from the paramos studied. Synecology: The reedswamps and grass mires are found on I) sloping wet areas , 2) flat, marshy valley floors, including former lake floors and 3) lake shore marshes. Similar phytocoenoses of limited size also occur in the superparamo, in springs and along paramo streams, in lake shore habitats regularly inundated and experiencing wave action, in the contact zone with Sphagnum bogs and calcareous mire. Depending on th~ kind of habitat and adjacent vegetation, conditions may be mesotrophic or eutrophic . Consequently, the pll in the rootzone varies from 4.5 to 7.5 in 34 relev~s. The waterlogged clayey-peaty subsoil is permanently in a state of reduction. Distribution: Most communities of the Marchantio-Epilobietalia occur in the upper superparamo and lower grass paramo of the Colombian Cordillera Oriental. Superparamo stands were studied up to 4450 m in the Cordillera Central and Oriental . The lowermost stand probably concern. the cyperaceous reedswamps (except Scirpus californicus) on the Sabana de Bogota (about 2600 m) and in other high plains of the Cordillera Oriental in the departments of Cundinamarca and Boyaca and is the lowest located vegetation. The MarchantioEpilobietalia is probably restricted to the paramos and open marshes in the upper part of the forest belt of the northern Andes from Venezuela to northern Peru.

.111

GALIO TRIANAE- GRATIOLION PERUVIANAE all. nov. type: Caricetum pichinchensis (this study); table

Physiognomy: The alliance comprises cyperaceous reedswamps with a conspicuous fieldlayer of 40-80 em high, covering 60-100% and a herbaceous bryophytic ground layer. Occasionally shrubby composites may develop into a higher third layer (cover about 70%). Flowers are mainly white to lilac. Composition & syntaxonomy: Cyperaceous reedswamp communities are dominated either by a distinct Carex species (C. pichinchensis, C. acutata, C. jamesonii or by Cyperus rivularis ssp. lagunetto). Senecio reissanus shrubs are locally dominant and are considered as climax vegetation, which belongs to a distinct assocation. Character species are thos e reported under associations (and communities), which are mainly hummock species and dominant in the fieldlayers and apart from those Galium trianae (excl.),Gratiola peruviana (select.) and Symphyogyna sinuata (select.), which are mainly less conspicuous hollow species. Differential species are Philonotis andina, Bryum grandifolium (both weak) and Lachemilla mandoniana. The Galio-Gratiolion may be considered as a cool neotropical vicariant of the holarctic Magnocaricion W. Koch 1926

(Phragmitetea). The herb Gratiola peruviana is widely distributed in temperate South America.In th e Colombian Andes this species grows on muddy and moist soil, in the open marshy parts at 2600 m in the Andean forest belt up to 3700 m in the grass paramo. Gratiola bogotensis Cortes is considered as a synonym of Gratiola peruviana L. by the present author. Galium trianae is restricted to the Colombian Andes and bridges a vertical range of the same height. Symphyogyna sinuata is a tropical Andean liverwort; from Colombia it is reported for wet habitats in cloud forest and bamboo paramo between 2150 m and 3700 m. Lachemilla mandonianawprerent along the humid high Andes from Bolivia to Venezuela. This tiny, extremely variable, prostrate species occurs throughout the Colombian paramos up to 4450 m. Note: Carex acutata, C. fecunda, C. jamesonii and C. pichinchensis may easily be confused. The number of species of the Galio- Gratiolion is 8-12 under pioneer conditions and 25-38 in stable closed communities. Synecology: The Galio- Gratiolion is present in humid and wet paramo habitats, including glacial valley floors, on former lakes, in hydroseral marsh and calcareous mire, in wet depressions and on sloping valley bogs. Most of the stands are in shallow water. A hummock-hollow relief is characteristic for this alliance except for the Carex acutata lake-shore community. This relief is common in paramo vegetation and in other humid to wet f ommunities, e.g. boggy Swallenochloa tesselata-moss (Sphagnv~, Breutelia) vegetation, Agrostis foliata community, hummock-like superparamo stands with Calamagrostis ligulata, Sphagnum bogs and vascular cushion bogs. In th路e locations of these paramo vegetations the water-table shows seasonal changes. Frost action in the hollows is most common in the higher paramos, and prevents the establishment of seedlings. The open and moist hollows suffer more frost damage than the thick compact plantcover of the hummocks. Rill erosion is prominent after abundant rains. The Galio-Gratiolion is common on thick, clayey peat or gyttja (pH of the root zone is 4.5-6.6). The Galio- Gratiolion is probably the main habitat for Cavia porcellus, which especially feeds on Cyperaceae. Populations of these animals live in these paramo reedswamps, where they maintain a pathway system through the sheltered hollows. These also serve as an excellent refuge in case of danger.

112

SyZviZagus brasiliensi s mer idensis a lso feeds on cyperaceous folia g e. Distribution: The alliance is known from the subparamo and grass paramo of the Colombian Cordillera Orienta l fr om 3300 to 3800 m. The sedge communitie s have onl y been s tudied in the southern paramos, the Cyper etum r ivuZaris was re corded in the northern Boyaca paramos (3300-3500 m). Car ex s p. and Cyperus sp. reedswamps have been recorded by the author in the paramo of the Colombian Cordillera Central. This alliance can be expected in other neotropical par amos, and in lowe r re gi.ons of the Andea n forest belt.

CARI CENION PICHINCHENSIS s uball. nov. typ e : Caricetum pichinchensis (this study ); table II Physiognomy: For a description of the diff e r ent laye rs, s ee the associations and community . Mo st o f th e dicot herb s pe cies of this suballianc e have white t o lil a c flowers. Composition & s yntaxonomy : Thi s suballiance comprises all ma rshy sed ge swamps in the herbaceous fieldlayer domina ted by Carex pichinchensis (selective character species). Exclusive character spec ies are Senecio reissianus and slender rosettes of VaZeriana pZant aginea . Diffe rential aga inst other communities of the Marchantio- EpiZobietaZia a r e LophocoZea coadunata,

GentianeZZa cor ymbosa, PoZytrichum commune , Thuidium peruvianum, PeZtiger a spp., Senecio canes cens (a low altitude species) and an unknown sp e cies of SeZagineZZa (5200). The high cover of Carex pichinchensis i s a lso differential against other phy tocoenoses, except for local Sphagnum bogs in the grass par amo, wh ere a similar high cover of this sedge spe c ies h ad been recorded . To gether with some other paramo swamps dominated by t a ll Cyp era c eae, this sub a lliance is ranked under the GaZio- Gr atioZion . Syne cology: The Caricenion pichinchensis occurs on c layey peat or ( cal careous) gyttja (topsoil pH 4.5- 6.6), with optimal developme nt on marshy glacial valley floors; a few stand were sampled in (lake ) hydroseral marsh and we t depressions. The hummock-hollow relief (described under the Caricetum pichinchensis ) is characteri s tic. Distribution: The available rel eves indicate that the Caricenion pichinchensis is found in the sub paramo and grass pa ramo between 3350 and 3800 m, ma inly in the Paramo de Sumapaz. The Senecionetum reissiani is endemic, wher eas the Car icetum pichinchensis may be present in other humid Andean paramos al s o. Note: VaZeriana pZantaginea is mainly native to the a tmospherical humid lower superparamo . The paramos contain two populations of VaZer iana pZantaginea at dif f erent altitudes, in different habitats and charac teristic for different communities: I) the widely distributed (lowe r) superparamo population of ground rosettes with firm fl e shy broad leaves and purple-violet corollas on we t rocks and on grave lly to coarse sandy soils (see 27); 2) the population of the grass paramo and subparamo with sl end er plants, sma ller leave s and whitish flowers, only in marshy places and e speci a lly in the Caricenion pichinchensis . Sp e cimens of the two populations are morphologically different at the infraspecific l evel, probably a t subsp e cies.

Ll.3

48.

Senecionetum reissiani ass. nov. type : rel. 139; table II; Fig. 47

Physiognomy: The vegetation structure of this microphyllous shrubby association is well defined: I) a grayish-leaved shrub layer (1-2 m) covering about 70%; the flowering aspect is yellowish. 2) a cyperaceous layer, 40-50 em high, covering 60-80%. 3) a prominent bryophytic layer (cover up to 80%) with low herbs and some shrub species (e.g . Hypericum prostratum, Arcytophyllum muticum, Pernettya

prostata). Composition & syntaxonomy: The dominant shrub Senecio reissianus is an exclusive character species; it is accompanied by the hydrophytic Hypericum laricifolium ssp. laricoides (differential species) and the conspicuous stemrosettes of the endemic Rumex tolimensis. Carex pichinchensis is dominant in the cyperaceous understorey,generally accompanied by Valeriana plantaginea and Gratiola peruviana. Ground rosette species as Senecio canescens and in the shadow Greigia cf. mulfordii (Brom.) are associated also. Common taxa in the bryophytic layer are Symphyogyna sinuata and Sphagnum sancto-josephense or species of Breutelia. The number of species is about 30 (range 25-38) in 2 releves. This is slightly higher than in other associations of the Galio-Gratiolion, possibly because of the extra (shrub) layer. Geranium confertum and Escallonia myrtilloides may be present in this association. Differential against other communities within the Galio-Gratiolion is Breutelia chrysea, and against those within the Marchantio-Epilobietal-ia are Hyper1:cum laricifolium ssp. laricoides, Hypnum mirabile and Cyclodictyon sp. Lichens are rare and restricted to the driest places. Common small, low herbs are Nertera granadensis, Selaginella sp. (5200), Lachemilla mandoniana, Muhlenbergia sp. This association is well defined and easily recognized by its exclusive character species Senecio reissianus . The association belongs to the GalioGratiolion andhas the closest floristic and ecological affinities with the Caricetum pichinchensis, and also has a number of species in common with the hydrophytic Hypericetum laricifolii (see 74). Synecology: The Senecionetum reissiani is found on marshy and peaty, gently sloping (0-5째) glacial valley floors or seepage areas with a more or less regular supply of water (pH 5.3 in rel. 139). The pH of the eutrophic clayey peat in the topsoil is 6.5. The Aoo layer is 3-5 em thick. The subsoil (measured every 25 em down to 125 em) in rel . 139, proved to be more acid downwa rd: pH 5.0-5.3. In the deeper part of the profile a rapid transition was noticed into blue-grayish sandy and clayey, increasingly gravelly deposits . Iron concretions around the roots indicate oxydation-reduction processes; oxydation was noticeable down to 50 em. This might correspond to the lowest phreatic level in the dry season. The Senecionetum reissiani possibly is successional to the Caricetum pichinchensis and apparently represents a more stabilized, slightly drier phase, characterized by structure, biomass and higher organic (peaty) content of the soil. The Caricetum pichinchensis, however, may also develop into Diplostephietum revoluti, and on more acid peat into Carex-Sphagnum bog (see other Sphagnum communities) Distribution: Senecio reissianus is endemic for the southern paramos of the Cordillera Oriental and especially common for the Paramo de Sumapaz. This species has been collected there in the subparamo and grass paramo between

114

3400 and 3900 m. In marshy paramo near the Laguna Verde, about 60 km N of Bogota, the author collected one specimen only.

49.

Caricetum pichinchensis ass. nov . type: rel . 138; table 11; Fig. 48 & 49 (also Fig. 41, 50, 51)

Physiognomy: This cyperaceous swamp vegetation consists of two strata: 1) a more or less solid 40-60 em high fieldlayer, dominated by the sedge Carex pichinchensis (60-100% cover), and generally poor in species . Valeriana plantaginea inflorescences are conspicuous; 2) a low herb-bryophyte layer, 1-10 em high, rich in species, in the shade of the overhanging sedges. The bryophyte cover is 2-3 em thick . Composition & syntaxonomy: Carex pichinchensis is dominant and a selective character species. In the study area it is accompanied by Valeriana plantagineawreferential character species~ Frequent are Gratiola peruviana,

Symphyogyna sinuata, Lachemilla mandoniana, Ranunculus flagelliformis, Nertera granadensis, and Senecio subruncinnatus. The Caricetum pichinchensis partly shows pioneer character. The number of species is low, 12 in rel. 277 and 18 in rel . 292. The average number of species in the stable valley floor communities of the 3 other releves is 28 (23-35). Synecology: The Caricetum pichinchensis is found in the subparamo and grass paramo on peaty soils in very wet habitats, with a regular supply of water. Large stands are present on glacial valley floors, limited communities in groundwater-wet areas around lakes and in muddy old moraine depressions in the lower paramos. The darkish-brown to almost black peaty clayey soils (including gyttja) are thick (>120 em) and the pH in the rootzone is 5 . 0-6.0. In the pioneer community of rel . 277, on a calcareous mire the pH of the top layer of the substrate was 6.6. Iron concretions on the roots indicate oxydation-reduction conditions in the topsoil. the sedge rhizomes may form a dense mat in the topsoil. A common featurP of the Caricetum pichinchensis is a kind of hummock-hollow relief . Four to five hummocks per square meter with a diameter of 10-15 em and a height of 5-20 em are usual. The highest hummocks are found in habitats with the greatest fluctuation in phreatic level. Common Carex pichinchensis hummock species are Valeriana plantaginea, Thuidium peruviana, Nertera granadensis and Dicranaceae. The muddy hollows contain Lachemilla mandoniana, Ranunculus flagelliformis, Philonotis andina, Scutellinia sp.(p); Calliergonella cuspidata, Gratiola peruviana, Selaginella sp. (8257), Sphagnum subsecundum and Gentianella corymbosa mark the transition from hummocks to hollows. Shepherds sometimes set fire to the sedge meadows, which in the dry season are grazed by cattle. Rodents, e.g. Sylvilagus brasiliensis and especially Cavia porcellus, forage on young Carex leaves. The last animal probably lives ln the dense Carex meadows. Distribution: The Caricetum pichinchensis is only known from the humid southern paramos of the Colombian Cordillera Oriental, and is common in the Paramo de Sumapaz . The association is present in the subparamo and grass paramo between 3400 and 3800 m. The highest located stand was observed near the Laguna Gobernador (Sumapaz). Judging .from herbarium specimens (NY , L, K), Carex pichinchensis must be widely distributed in the tropical Andes from Bolivia to Colombia . In Colombia this sedge species was collected from 2600 m (Sabana de Bogota) up to 4500 m

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in the superparamo of the Cordillera Central and Oriental and in the Sierra Nevada de S. Marta. VaZeriana pZantaginea is only known from atmospherical humid Colombian and E~uadorian paramos between 3400 and 4400 m. In the northern paramos of the Colombian Cordillera Oriental and in the Sierra Nevada de S. Marta, VaZeriana pZantaginea is rather scarce. The Caricetum pichinchensis is probably present in paramos of the Colombian Cordillera Central and the Ecuadorian Cordillera Oriental. Notes: Small patches dominated by a bluish Carex sp. (probably C. pichinchensis) have been studied on the volcanoes Purace (3300 m) and S. Isabel (4170 m) and in the Sierra Nevada del Cocuy (3950 m). These communities do not contain VaZeriana pZantaginea and may represent another syntaxon. According to Dr. T. Koyama (NY) another large Carex species, C. fecunda, is locally found together with Carex pichinchensis.

50.

Community of Carex pichinchensis and PoZytrichum commune table II

Physiognomy: layer of 10-20 em.

This type of sedge swamps is

characterized by a musci

Composition & syntaxonomy: PoZytrichum commune is the most characteristic species, which furthermore only has been recorded in paramo Sphagnum bogs. Sphagnum mageZZanicum is common in rel. 80 and apparently develops into Sphagnum bog. ArcytophyZZum muticum, Hypericum prostratum, Geranium sibbaZdioides, CaZamagrostis bogotensis and PaspaZum bonpZandianum mark the transition towards the surrounding dry grass paramo. PoZytrichum commune, ArcytophyZZum muticum, Geranium sibbaZdioides, Leptoscyphus cZeefii and Hypericum prostratum are not present in other reedswamp communities. Synecology: This community of sedges and mosses is found along paramo streams on thick humid (rel. 144) and wet ground (rel 80) and is flooded in the wet season. The dark reddish-brown to gray silty to clayey soil layers in rel. 144 are str.eam deposits, the gyttja in rel. 80 is a lake sediment, now deeply incised by the adjacent stream. Rootzone soils are acid: pH 4.5-4.7. In rel. 144, at a depth of 70 em, the soil consists of a 1.5 em thick compact layer of plant remains, charcoal and fragments of gra7el. Oxydation colours can bP. noticed above this layer. PoZytrichum commune is common, and the layer is 1.5-20 em thick. Sphagnvffi mageZZanicum cushions (up to 10 em) grow on litter. Rel. 80 has a dense cover of the hydrophytic CaZamagrostis cf. pZanifoZia. Distribution: This sedge community, studied in the Paramo de Chisaca (3600-3700 m), was also observed at 3.520 m on the Nevado d路e Sumapaz and can be expected elsewhere in the Paramo de Sumapaz. Other cyperaceous communities

51.

Community of Carex acutata characteristic rel.: 26.5; table II; Fig. SO, 51

Physiognomy, composition & syntaxonomy: These two-layered paramo reed swamps contain Carex acutata dominant in the field layer. The bryophyte layer is dominated by Symphyogyna sinuata (3-4 em high) in well-developed stands. This type of sedge vegetation is poor in species; the average number is 10

116

(8-11 in 2 releves) . This is probably to be attributed to the pioneer character of this sedge community along lake shores. Carex acutata reedswarnps have their optimal development in the Andean forestbelt. Synecology : The pararno Carex acutata community is part of a reed belt in lake hydroseral zonation between the Potameto-Myriophyllion of the open water and the Sphagnum-Calamagrostis ligulata rnarhs directly near the lake water (Fig. SO , 51). The substrate is eutrophic peat (rootzone pH 6.3), always wet or humid, also in the dry season . In rel . 265 the peat and lake sediments are at least 8 . 25 rn thick as shown in the pollen section La Primavera (Fig . 7) . A hummockhollow pattern is absent. This reedswarnp is rather a hollow- than a hummock vegetation , represented by the neighbouring boggy Sphagnum-Calamagrostis ligulata vegetation . Rel. 267A is less typical and grades into this vegetation (rel. 267) . Table 12

Ludwigia peruviana shrub

rel . nr. alt . cover shrub layer cover herb -layer number of species

423B 2800 rn 90% 95% 4

cover %

Ludwigia peruviana var . peruviana Carex acutata Polygonum sp. (10 . 034) Hydrocotyle ranunculoides

90 80 2

Distribution : The pararno Carex acutata community is only known from the marshy NW shores of the Laguna La Primavera at 3525 rn in the Paramo de Surnapaz (Meta) . Carex acutata is widely distributed in the tropical Andes between 2400 and 4000 rn. This sedge species is more common in the lower reaches of the Andean forest belt . In the Laguna La Herrera on the Sabana de Bogota (2560 rn) there is a Carex acutata reedswarnp (I rn high). Another cornffiunity with Carex acutata has been studied at 2800 rn in the Sierra Nevada del Cocuy in a small lake (El Claval) , some krn SW of Guican (Boyaca), with a dense shrub (2 rn high) of the widely distributed , yellow flowering, onagraceous Ludwigia (Jussiaea) peruviana var . peruviana . Rel . 423 B was made in this location (see table 12) . This stand probably represents an undescribed association (Ludwigietum peruvianae prov . ) On the water under the Ludwigia shrubs floated the LemnoAzolletum filiculoides (nr. 47) with Azolla filiculoides (SO%) and Lemna minor (10%) . 52.

Community of Carex jamesonii characteristic rel.: 309 ; table II ; Fig . 14 Physiognomy:

The reedswarnp of this community consists of two layers ;

Carex jamesonii is dominant in the field layer (30-40 ern) . Composition & syntaxonorny : Carex jamesonii grows on top of the 10-15 ern high hummocks with Lachemilla mandoniana , in some places together with

.U7

tussocky Calamagrostis effusa . Dwarf shrubs of Pernettya prostrata var . purpurea and Blechnum loxense are found in the transition to the humid hollows covered with a herb-bryophyte layer mainly consisting of Callitriche sp . and cf .• Odontoschisma sp. (8420) . Symphyogyna cf. sinuata is rare . Carex pichinchensis is present in the lowermost waterlogged area of this bog . The number of species is 20 . Rel. 309 represents a Carex jamesonii subpararno community belonging to the Galio-Gratiolion . The diagnosis is only based on the single releve available. Cyperus sp ., Sibthorpia repens and Blechnum loxense are also characteristic for swamps and bogs in the lowermost pararno belt . It is possible that the reported Carex jamesonii community is altitudinally vicariant with the Caricetum pichinchensis in the Paramo de Surnapaz . Synecology : As shown in Fig. 14 the Carex jamesonii stand occupies a convex bog site on sloping ground (9°) in a small subpararno valley . The pH of the clayey peat in the rootzone is 5 . 8 . About 8 months before our visit this stand had been burnt, and this explains the presence of the rather open cyperaceous field layer (cove·r 75%). Whether dominance of cf. Odontoschisma (versus Symphyogyna) in the bryophyte layer is due to the burning is not known . Scirpus inundatus and Juncus species with low cover are species indicating manuring by cows . Shrub of Diplostephium revolutum occurs in the Carex jamesonii meadow and is probably succesional to this sedge community. Cavia porcellus forages on Carex jamesonii foliage . Distribution: The stand with Carex jamesonii is from 3560 rn (upper subpararno) near the cloud forest line on the Magdalena slope in the Paramo de Surnapaz. Carex jamesonii is a widely distributed and common sedge species on boggy ground in moist woods and subpararnos in the northern Andes (Venezuela to Ecuador) between 2000 and 3600 rn. Habitats recorded from herbarium collections are : dry Sphagnum bog (colonies), Sphagnum meadows , moist cliffs, ditches, seepage areas , etc. 53.

Cyperetum rivularis ass . nov . type : rel. 234; table 11; Fig. 52 Physiognomy:

Like all other herbaceous communities of the Galio-

Gratiolion, this association consists of 1) an impressive, dense fieldlayer dominated by Cyperaceae ((50-) 70-80 (-100) ern), developed above 2) a generally shaded (low) herb-bryophyte layer . The moss layer may be 5-15 ern thick. Characteristic are the compact inflorescenses of giant Puya sp. reaching 1-2 rn above the fieldlayer . Composition & syntaxonorny: Cyperus rivularis ssp . lagunetto is the prominent species in the fieldlayer. Common species are Sibthorpia repens, Lachemilla mandoniana, and Nertera depressa. One tall Cortaderia sp. (probably C. nitida) was seen codorninantly (rel. 409) . Characteristic are species of Puya, e . g . Puya bicolor, Puya santosii . Mosses, e . g . Brachythecium sp. and Sphagnum recurvum, may be dominant in the bryophyte layer and cover up to 80-90%. The number of species is 9 (rel. 235) to 23 (average of the other 3 releves) . The Cyperetum rivularis is well defined by its character species Cyperus rivularis ssp. lagunetto (excl. ?), Sibthorpia repens (pref.) and a small unknown species of Scirpus subg. Isolepis . Puya santosii is a differential

118

speci es . The Cyperetum rivu laris is an altitudinal vicariant with Caricetum pichinchensis though both associations of the Galio- Gratiolion a~ described for different parts of the study area. The low and creeping, Sibthorpia repens is a sel ec tive character species of the Hypericetum laricifo~ii (74) a paramo shrub community on humid. ground, whi ch has also some other under s tor ey s pec i es in common with the Cyperetum rivularis. Releve 387 contains taxa from adjacent vege tation (Eleocharitetum macr ostachyae ,

Oritrophio-Wernerietalia) . Synecology: The Cyperetum rivularis is restricted to wet subparamo habitats on peaty poorly-drained g lacial valley floors, especially in former lakes. The thi ck wa terlo gged profiles consist of clayey peat or gyttja. Rootzone pH is 5.3-6.4 . In rel. 235, a compact probably cyperaceous peatl aye r was observed at a depth of 80 em . A hummock-hollow reli e f similar to that described for 路 the Caricetum pichinchensis is generally pres ent. The hummocks are b es t developed in rel. 409, where they have a diameter of 30-50 em and a height of about 25 em, probably caused by fluctuations of the phreatic level. In the wet season the hollows become inundated. A distinct pleustophytic community (Lemno-AzoUetum) consisting of AzoZZa fiZiculoides and Lemna minor may be floating in the hollows. The hummocks mainly carry Cyperus rivularis and Cortaderia sp . The hollows are poor in species. Recorded ar e Elatine cf. chilensis, Callitriche sp., Ranunculus flagelliformis, Philonotis andina, sphagnum recurvum, Drepanocladus fluitans and D. lycopodioides. Gratiola peruviana is an excellent colonizer on barren mud. This s pecies is absent, when Sphagnum and Barchythecium species colonize Cyperus litter effectively. Large Cortaderia tussocks replace the Cyperetum in deep er parts of the swamp, where the vertica l fluctuation of the phreatic level is higher (Paramos de la Rusia & Guina) . Rel. 234 contains many seedlings of Escallonia myrtilloides var . myrtilloides. As frequently observed in the lower paramos, this species locally develops into small dwarffores ts on swampy ground along streams . Hirts sometimes set fire to the Cyperetum rivularis. Mainly Cavia porcellus, but also Sylvilagus brasiliensis forage on Cyperus foliage. Frogs are common . . Distribution : The Cyperetum rivularis is only known from the lower paramos (lower grass pararno, subparamo) between 3300 and 3500 m in the Department of Boyaca. In the Colombian Cordillera Central a reedswamp dominated by Cyperus sp . (probably the same species) was seen at 3900 m near the forest line in the Romeral valley, W slope of the volcano S . Rosa. Azor ella multifida and slender rosettes of Valeriana plantaginea were associated.

CALAMAGROSTION LIGULATAE all. nov . type: Geranio confertae - Calamagrostietum ligulatae (this study) Physiognomy: The closed vegetation of this alliance is stratified into two layers: I) a predominantly graminoid fieldlayer, up to 50 em high , and 2) a ground layer of mosses or low matted herbs. Composition & syntaxonomy: Character species are Calamagrostis ligulata (select.), Cerastium imbricatum (select . ), Montia fontana (select.) and Plantago australis ssp. oreade s (excl.). Scorpidium scorpioides is differential against the Galio-Gratiolion. Drepanocladus aduncus is hardly

JJ9

present out s ide this alliance. The ave rage number of species varies from 13 (7- 26 ) in the pioneer communities up to 23 (14-36) in the more stable Bryo - Cari~enion bonplandii . The Calamagrostionligulatae comprises various kinds of paramo vegetation with Calamagrostis Zigulata (including communities with uncertain status). An exception is the Carici-Wernerietum crassae (Oritrophio-Wernerietalia), with Calamagrostis Zigulata as a weak differential species. Cuatr ecasas \1934) reported Cala~agrostis Zigulata from the bunchgrass and lower s up e rparamo (3800-4430 m) of the Nevada de Tolima, in small groups with limited cover. Recent releves in th e same area (volcanoe s S. Isabel - S. Rosa) indi ca ted the presence of this grass species in the azonal paramo vegetation (Cleef e t al., in press). Synecology: The paramo mires of the Calamagrostion Zigulatae are found in various environments: on sloping ground with accumulations of water, on mars hy valley floors, on former lake floors, in lake-shore hydroseral zonation, in st r e ams, in swamps, and on calcareous mires in doline s . The mesotrophi c to eutrophic c layey to peaty substrates are generally thick with a rootzone pH varying from 5. I in boggy ~onditions to 7.5 in the most eutrophic habitat in calcareous mire. Distribution: The alliance is mainly based on releves from the subparamo and gr ass par amo of the Colombian Cordillera Oriental between 3400 and 4000 m. The hi ghest communities (4430 m) have been record ed in the superparamo . The Calamagrostion Zigulatae is also present in the paramos of the Colombi an Cordillera Central and probably a lso in those of th e Sierra Nevada de Merida in Venezuela (Va reschi 1970) and in Ecuador. Calamagrostis chrysantha ma inly forms grass mires in the Peruvian puna between 4500 and 4750 m, ac cording to Ra uh & Falk (1959) and Gutte ( 1980). The l a tter described the Calamagrostietum nitidulo- chrysanthae Gutte, which app ar entl y belongs to another undescribed, but geographically vicariant alliance of the Calamagros tion Zigulatae .

BRYO- CARICENION BONPLANDII suball. nov. type: Geranio confer tae - Calamagrostietum Zigulatae (this s tudy); table II Phys io gnomy :

See alliance.

Composition & s yntaxonomy : Charac ter spec ies are: Bryum Zaevigatum (almo s t excl.), and another still unnamed Bryum sp. (e.g. B. c f. ellipsifolium) , Stachys elliptica (sel.) and Senecio niveo~ aureus (pref.). Differential s pecies are Care x bonplandii , Muhlenbergia sp(p)., Juncus cyperoides , Scirpus inundatu ~ and Leptodontium Zongicaule var. microruncinnatum. The aver,age number of speci es is higher than in the other communities of the alliance , and is 23 in 13 releves (14-36). Most of them are vascular plants and mosses. The Bryo- Caricenion bonp landii comprises all stable species-rich Calamagrostis Zigulata paramo mire vegetations in the Colombian Cordillera Ori ental, which are without extreme environment al factors. Synecology : This suballiance comprises wel-developed stable pararno mire communities on sloping (up to 120) peaty gr ound, in valley floor swamps and bogs, and in hydrosera l sequence on swampy lake-shores. The Calamagrostis Zigulata cover is higher (about 45%) in comparison to the other communities in more extreme habitats. The depths of the peaty substrates and sed iments vary con si derably , from I m to 8 m or more. Root zone pH is 5.1-7.1 and clearly r ef l ec ts me sotrophic and eutrophic habitats.

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Distribution: This suballiance occurs from the subparamo up into the superparamo, from 3400 to 4 150 m, in the Colombian Cordillera Oriental. The highPst record is of the community with Senecio niveo- aureus and Breutelia (SSe) in the upper condensation zone on the Nevada d e Sumapaz. Note: Whitish, broad-leaved, giant rosettes of Senecio niveo- aureus with lax inflorescences are r estricted to these cold azonal paramo mires. The Senecio niveo- aureus populations ma.inly represent zonal superparamo communi ties (26) on the climatologically humid side of the mountains.

54.

Lupino alopecuroides - Mimuletum glabratae ass. nov. t ype : r e l. 101; tabl e 11 ; Fig. 13 Physiognomy:

Thi s rather c l osed herbaceous vegetation is stratif ied in:

I) a high herb-tussock grass layer of 50-100 (150) em, covering about 75-100%,

and 2) a low herbaceous - bryophyte mat, covering 30 to nearly 100% of the surface. The cover of bryophytes, mainly pleurocarpous mosses and some thallose liverworts, is 5-30% . Lupinus alopecuroides , Senecio niveo- aureus, S. sp. nov. (5736; rel. 169) and Calamagrostis ligulata are mainly present in the upper layer, whereas Mimulus glabratus, Ranunculus flagelliformis, Brachythecium sp. (4230) and Bryum sp. (4228, 423 1) belong to the ground layer. Composition & syntaxonomy: This association is rich in hydrophytic herbaceous species. Character species are Lupinus alopecuroides (excl.) Mimulus glabratus (select.); Calceolaria mexicana (sel ec t.), and probably Anomobryum plicatum.This last moss species is in the Colombian Andes only known from the Paramo de Pisva(3480-3600m). Bartsia sp. (reddish flowers) and Sisyrinchium tinctorium are differential species. Br achythecium sp. (e.g. B. f~exiventrosum) are prominent in shady places. The number of species ranges from 22 to 36 in th e two releve s available and is highest at lower a ltitude. The closest affinity is shown to the Geranio- Calamagrostietum drabetosum (55a). Synecology: The Lupino-Mimuletum is found in eutrophic wet flush on slopes (7-J2D). The continuously perculating wa t er is enriched by minerals from the surrounding paramo. The pH is 6.1-6.3 (flush water) and 7.1 (filtyhumic rootzone) ~ Thickness of the clayey to peaty substrate varies from 30 em (rel : 169) to 100 em (rel. 101) . A sandy or clayey layer containing angular gravel is present at the base of the peat. Presence of Lupinus alopecuroides contributes to the high content of nitrogen in this habitat. Frogs, insect larvae and bivalves of Sphaerium lauricochae were observed in the Lupino- Mimuletum. Trampling by cattle and foraging activity of Sylvi lagus brasiliensis are common. Distribution: This association is described from the Sierra Nevada del Cocuy (4000 m) and the adjacent Paramo de Pisva (3480 m), but stands close to the cloud forest line have also been observed in the Paramo de Pala~io (Cundinamarca) and in the Paramo de Sumapaz (Meta). The Lupino- Mimuletum is most common in the atmospherically humid subparamo on the E side of the Colombian Cordillera Oriental. It is present in the subparamo and the lower grass paramo. Mimulus glabratus is a wi dely distributed species in the temperate and cool mountains of tropical America. Lupinus alopecuroides is only known from the Colombian and Ecuadorian paramos. Thus, the Lupino~imuletum is likely to occur in the latter area, probably mainly in subparamo stands under humid

121

conditions,as e.g. ontheOrinoco and Amazonian side of the Colombian and Ecuadorian Cordillera Oriental . Note: In the author's opinion the Ecuadorian and Colombian paramos contain two populations of Lupinus aZopecuroides, 路which are morphologically different at infraspecific level: I) a superparamo population (high paramo up to 4700 m) with large, compact, columnar inflorescences and densely tomented leaves, and 2) a lower paramo population (3000-4000 m), dull greenish, with more loose and slender inflorescences, on wet ground, bog and peat. Lupinus aZopecuroides of the Lupino- MimuZetum belongs to the latter population . It is ass umed that Pleistocene glaciations caused sp a tial isolation, resulting in morphological and ecologica l differences. The same applies to Senecio niveo- aureus (see Br yo- Caricenion bonpZandii and VaZeriana pZantiginea (see Caricenion pichinchensis). 55.

Geranio confertae - CaZamagrostietum ZiguZatae ass. nov. type: rel. 109; table II; Fig . 42, 51 , 53. Physiognomy:

The association is characterized by:

I) a graminoid fieldlayer, covering as much as 80%;

2) a groundl aye r, dominated by low herbs or mosses. Composition & syntaxonomy : The character species CaZamagrostis ZiguZata (trans gr.) is prominent . Geranium confertum is a selective character species. Other character species are Mantia meridensis fma. , Draba sp. (264a; white pe tals) and Lupinus cf. verjonensis. The identity of the two last species has not ye t been determined. HaZenia sp(p.), Hypericum Zancioides~ BreuteZia aZZionii and B. chrysea are differential species. Mosses in stable stands cover about half of the surface, with as repre s entatives BreuteZia aZZionii ~ B. chrysea~ CampyZopus cavifoZius and Bryum Zaevigatum. The average number of species is 20 (14-32) in 10 releves. In addition to its charact e r and differential specie s, the Geranio-CaZamagrostietum ZiguZatae is differential against other communities in extreme paramo environments by its abundance in (moss) specie s , and hi gher grass cover ( average 40% versus 12%). Geranium confer tum has not yet been notice d in CaZamagrostis ZiguZata mires in the Colombian Cordill er a Central, but on the basis of herbarium data this species occurs also in Ecuadorian paramos ; it is characteristic for the Hyperico- PZantaginetum rigidae breuteZietosum (65b). Synecology: The Geranio-CaZamagrostietum ZiguZatae is a community of paramo mires on former lake (drabetosum), on marshy lake- shores and on fl a t or gfl ntly sloping valley floors (predominantly breuteZietosum ). It is found in mosaics together with reedswamps (GaZio-GratioZion peruvianae ) or bogs dominated by Sphagnum and vascular cushion pl ants. The anaerobic clayey to peaty substrate is mesotrophic to eutrophic, with a rootzone pH of 6 (5 . 5-6.5). Sit es s urrounded by Sphagnum bogs are usually more acid in the toplayer . In most places the peat is thicker than I m, and sometimes more than 8 m (former lakes). Dense moss carpets are common on the c lima tolo gic a lly humid side of the mount a ins. Type, nature and dominance of the almost continuous moss stratum are controlled by edaphic conditions. Generally, CaZamagrostis ZiguZata tus sod<.s are the first to colonize on mire , followe d by a c l os ing of the mos s c arpet. There is mainl y foraging b y SyZviZagus ~ Cavia and cattle. Snails of PZekochei"tus succinoides cZeeforum were co llect e d in rel . 127.

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Distribution: The association is restricted to subparamo and grass paramo mires of the Colombian Cordillera Oriental where is was studied between 3400 and 3900 m. In the author's opinion the stand in releve 286 at 4120 m in the lower superparamo of the Nevada de Sumapaz may represent an undes~ribed association restricted to the upper condensation zone (see SSe). Note: Mantia cf. meridensis is a common lax plant, the leaves of which bear two conspicuous teeth; it has white, orange and pink flowers in Calamagrostis ligulata mires. For the moment these specimens (e.g. 275, 1022, 1030) are considered as low altitude members of the superparamo population. The superparamo population of Mantia meridensis in the Colombian Cordillera Oriental is morphologically characterized by: I) a compact cushion-like appearance 2) white flowers with a faint yellowish hue 3) two smaller apices per leaf ssa. Subass. drabetosum subass. nov. (prov.) type: rel. 127; table II; Fig. 53 Physiognomy: Stratification is in two layers: I) a ground layer, consisting of a dense cushion-like mat of low herbs, tiny grasses and mosses, and 2) an open tussock grass layer (15-50 em high) with whitish rosettes of

Senecio niveo- aureus . The herbaceous matted groundlayer i s often covering in an undulating way the underlaying clayey peat, thus causing a relief of hummocks and hollows (Fig. 53). Composition & syntaxonomy: Differential species are herbs in low mats or low cushions: Draba sp. (264a, 5261) and Lupinus cf. verjonensis (2609, 5262). In some places, Festuca sp. (5259) tussocks replace most of the Calamagrostis ligulata clumps. Cyclodictyon sp. (4820, 5264) and Brachythecium spp. (4819, 5270) are differential moss species against other communities of the Calamagrostion ligulatae . More rel eve s are required to confirm the present rank of this subassociation Festuca sp. bunches are only locally present in the azonal communities (especially in Sphagnum bogs) of the paramos in the Colombian Cordillera Oriental. The taxonomic status of this grass species and of the species Lupinus and Draba still remains uncertain. Synecology: This vegetation type is restricted to boggy mire covering former lake bottoms and also occurs locally on wet slopes. The pH of the clayey peat immediately under the low herbaceous mat i s 5.2 and 6.2 in the two releves. Muhlenbergia sp., Draba sp., Cerastium imbricatum, Brachythecium sp., Bryum ellipsifolium and Bryum sp. (4818) preferably grow on the cavernous hummocks of about 10 em high, whereas the hollow habitats contain Marchantia berteroana, Cyclodictyon sp., Bryum candicans, Reboulia hemispherica, Callitriche sp., Nerteria granadensis,Lupinus cf. verjonensis and Spirogyra sp. Distribution: This vegetation type has only been studied in the Paramo de Sumapaz between 3600 and 3900 m. The Draba species is probably identical with the not yet indentified Draba species with white petals (e.g. 1310, 1312), which abound in the

Note:

superparamo in the upper reaches of the Nevado de Sumapaz. If this proves to be correct, the Draba specimens (261Ia, 5261) in both releves are an example of a supPrparamo species in a cool grass paramo mire habitat.

J 23

55b. Subass . breutelietosum subass. nov. type: rel. 109; table II ; Fig. 42 (see also Fig . 51) Physiognomy : Just as in the association, two layers can be di st inguished. I) a graminoid fieldlayer, 30- 60 em high, covering about h a lf of the area. 2) a near ly closed 10-15 em thick moss carpet. Vascular plants are locally prominent . Composition & syntaxonomy: Br eutelia allionii and/or B. chrysea are diff erential as regards pr esence and higher cover (25-75%). In most releves the cover of Calamagrostis ligulata is 60% or more. The breutelietosum can be rea dily distinguished by it s conspicuous moss cover; the numb e r of species is differential against other moss-dominated communiti es of the Calamagrostion ligulatae. Synecology :

The breutelietosum occurs in 2 habita ts:

I) in hydroseral lake-shore mir e s ,

2) on boggy slopes surrounded by Sphagnum bog or by cushion bog of the

Hyperico-Plantaginetum rigidae.

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Ori g in and nature of the water in these paramo mires reflect in the values of the clayey or peaty rootzone. In eurotrophic lake -shore mires the pH is 6.0- 6.6*, and in mesotrophic habitats in contact with Sphagnum bog 5.1-5.8 . Di s tribution: This moss y subassociation is common in the subparamo and grass paramo (3400-3875 m) on the humid side of the Colombian Cordillera Oriental , and was also obs erved between 3800 an 4100 m on forme r lake floors on the SE- si de of the Nevado S . Isab e l, Colombian Cordill e ra Central.

55ba Variant of Campylopus cavifolius type : rel. 295; table II ; Fig . 42 Physiognomy & composition : Campylopus cavifolius is dominant in the moss layer, in association with other bog elements, e.g. Pernettya prostrata var. purpurea~ Riccardia spp ., and locally with Anastrophyllum leucocephalum and Lepidozia macr ocolea . Campylopus cavifolius may be absolut e dominant and then forms a conspicuous flat compact turf. Synecology:

With a less r egular drainage and aera,tion, a thick compact

Campylopus cavifoUus turf develops in the breute Uetosum, which may become absolutely dominant under bog conditions. The green to light- brownish

Campylopus cavifolius is about 10- 15 ern high . At the base of the moss layer is a thin blackish stratum (pH 5 . 1-6.6*), which deeper passes into a grayish peat . The upper part of the Campylopus cavifolius peat contains many caterpillars. Distribution : The variant has only been studied in the southern paramos (Sumapaz, Palacio) of the Cordillera Oriental b e tween 3400 and 3650 m. It may be expected in other paramos of the Cordillera Orient a l. The variant was also observed at 3800 m on the SE side of the Nevado S . Isabel, Colombian Cordillera Central.

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SSe.

CaZamagrostis ZiguZata community with BreuteZia aZZionii, Senecio niveo-aureus and LuzuZa gigantea characteristic rel .: 286; table 11

Physiognomy : The vegetation structure is similar to that mentioned for the breuteZietosum of the Geranio-Calamagrostietum ZiguZatae. Composition & syntaxonomy: Several species are differential against all other communitie s of the CaZamagros tion ZiguZatae. Part of thes e are superparamo taxa:e.g. Poa cf. pauciflora, Dr aba sp. with yellow petals (8108) Draba sp. with white petals (1310, 1312), LachemiZZa tanacetifolia. Near l y al l species ar e hygrophytic and most of them skiophytic, generally found under paramo shrub and thickets in lower loca tions , e.g. LuzuZa gigantea and Thuid1"um peruvianaum. in shady habitats and Rhacocarpus purpurascens and Breutelia aUionii in the open high paramo. This superparamo community fits best in the GeranioCaZamagrostietum ZiguZatae . Geranium confertum was found as sociated, but is absent in rel. 286. Synecology & distribution : This community was only observed in humid depressions on the slopes of the lower superparamo in the summit area of the Nevado de Sumapaz between 4100 and 4200 m. The thin dark-brownish clayey soils are ove rl ying lime s tone rocks. The pH of the rootzone was 6 .2. Floristic composition and plantcover of this stand reflect the presence of an upper condensation zone. The clouds which most of the time cover the peak bring about an open hygrophytic and skiophytic vegetation of these heights. SyZviZagus forages on LuzuZa gigantea . Cattle sometimes grazes in higher areas.

Other CaZamagrostis ZiguZata communities 56.

Community of CaZamagrostis ZiguZata with Mantia fontana characteristic rel.: 296; table 11'; Fig . 49

Physiognomy, composition & syntaxonomy: This paramo spring vegetation is dominated by herbs in contrast to holarctic spring vegetations, which are general ly rich in bryophytes ( e.g. De Molenaar 197 6). The spring community here described stands out by its higher cover of photophytic herbs: e.g. Mantia fontana (20- 80%) and EpiZobium mer idense (S-8%), while bryophyte species are scarce. The number of species is 14 (13-15) in the two releves . Host conspicuous is the low herb layer with some pleurocarpous mosses and Marchantia pZicata; this layer is slowly percolated by wa ter rich in oxygen. This spring community fits well in the Calamagrostion ZiguZatae. It may r epresent a proper assoc i ation . Note: A herbfield is often developed on marshy banks of paramo streams, and may b e dominated by one of the followin g species: MimuZus glabratus, Cardamine africana or Mantia fontana. These communities have close floristic affinities with the here described paramo spring vegetation . Synecology: RanuncuZus flageZZiformis and EZeocharis stenocarpa have much higher cover values in lake-shore habitats. The pH of the clayey to peaty rootzone was 6 . 6 and 6.7 in the two releves . Black leeches and frogs are common. Distribution: The studied stands are located in the Laguna La Guitarra marshes a t 3425 m in the upper subparamo of the Paramo de Sumapaz. The

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community was also observed in mires on the valley floor of Lagunillas, Sierra Nevada del Cocuy and can be expected in the paramos of the Cordillera Oriental. Further , it is also known from the Nevada de S . Isab e l a t 3800 m in the Cordillera Releve 629 in that place has been used for the present diagnosis. Central. 57.

Community of Calamagro stis ligulata with Sphagnum sancto-josephense characteristic rel.: 267; table II; Fig. 50 , 51 Phys io gnomy :

I) a closed

The community i s structured in two layers:

Sphagnvm pea t layer, in wh ich small vascular plants may attain a

high cover, and 2) an open field layer, mainl y 30-50 em high mire grass clumps with a cover of 15%. Composition & syntaxonomy: The lake-shore mire s are dominated by pea t mosses , e.g. Sphagnum sancto-josephense , S. magellanicum with Pleurozium schreberi, and the rare Lophozia cf. patagonica (see taxonomical comments of Dr . R. Grolle in Gradstein & Hekking 1979). Rel . 400 . in the Paramo de Palacio near Bogota is the northernmost l ocation of this tiny cool -t emperat e austral liverwort species . Eleochari s stenocarpa has a high er cover within the reaches of the lake water (rel.400) and a lower cover in peat bo g (rel . 26 7) , 16 resp. 13 species were recorded in the two releves. Peat bog species are differential against other communities of the Calamagrostion ligulatae. This community is somewhat intermediate between the Calamagrostion ligulatae and the (paramo) Sphagnum bo gs, Synecology: This is a peat bog community in the hydr oseral zonation ~n paramo lakes. The stand may be in direc t contact with open water in lakes the Carex surrounded by Sphagnum bog (rel . 400) or separat e d there from acutata community (rel. 267a) in the transition from open water towards Swallenochloa-Sphagnum bog or Diplostephietum revoluti (Fig . 50, 51). At least the upper part of the substrate consists of Sphagnum peat . The pH* in the top layer of rel . 400 was 5.3. A floating or emerging moss community, consisting of Drepanocladus exannulatus (60% cover) and Sphagnum cuspidatum (40% cover) , is locally found along the shores of the lakes with Sphagnum bog (rel. 399; pH* 4.8) . Distribution: The community is known fr om the southern lower grass pa ramos in the Cordi llera Oriental, at a height of 3350 m. The communi ty must b e pres ent elsewhere in lacustric hydroseres in the lower paramos of th e Colombian Andes . 58 .

Community of Calamagrostis ligulata with Drepanocladus aduncus and Calliergonella cuspidata characteristic rel.: 279; t able II Physiognomy :

This community is composed of two distirict layers:

I) a more or less open ground l ayer , mainly of hydrophytic mosses,

2) an open grarnino id field layer , about 30 em high cove ring about 25% of th e 路 surface. Composition & syntaxonomy: This mire community is rather poor in species ( 7-10 in 2 releves), and dominat ed by pleurocarpous mosses (either Drepanocladus aduncus or Calliergonella cuspidata). High tussocks of Calamagrostis ligulata, Scorpidium scorpioides, Campylium sp., Elatine cf. chilensis, Cardamine bonariensis,and small brownish mushrooms (Agaricales) are 路 generally a ssociated species .

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This community probably represents a rare, distinct calciphytic association within the CaZamagrostion ZiguZatae. It is also to be expected in other paramos with calcareous rocks, e.g. the Paramo del Almorzadero. Furthermore this community seems geographically vicariant with holarctic calcareous mire communities, e.g. with CaZamagrostis negZecta stands(Scheuchzerio-Caricetea) described from Greenland (Becher 1933, De Molenaar 1976, Daniels 1980). Synecology & distribution: This rare basiphytic community has only been found on calcareous mire in a deep doline at 3480 m, on the NW slope of the Nevada de Sumapaz and quite close to the northeastern shore of the Laguna El Nevada. The unstable mineral or clayey-organic soils are in a permanent state of reduction; the phreatic level is at the surface or slightly higher (in january 1973) . The community represents the early pioneer stage,with DrepanocZadus aduncus (rel. 279) on the bare, waterlogged mineral soil (pH of the top layer 7.5) and a more stable and closed cover of the CaZZiergoneZZaCaZamagrostis ZiguZata community (rel. 278) on clayey organic soil (pH rootzone 6.5). Part of the DrepanocZadus aduncus mat apparently dies off during the low water period in the dry season. This causes mosaic-like mossy patches. A core drilled to a depth of 8 m showed alternating organic moss turf and mineral sediment with scarce pollen. In the same doline, also the Caricetum pichinchensis (rel. 277) is found on more stable calcareous substrate. Cavia and SyZviZagus frequentl y visit the locality . 59.

Community of CaZamagrostis ZiguZata with IsoZepis sp. (5603) and CaZZiergoneZZa cuspidata characteristic rel.: 162; table II Physiognomy:

The community is structured in two layers:

I) a predominant 5 em thick moss layer with small and low herbs covering the

surface. 2) an open graminoid field layer up to 35 em high, covering up to 30%. Composition & syntaxonomy: This mire community is rich in species (26 in rel. 162) and is dominated by IsoZepis sp. (5603) and CaZZiergoneZZa cuspidata. Many species are characteristic of the Oritrophio-WernerietaZia: e.g路. LuzuZa vuZcanica, AUensteinia paZudosa, Gentiana sedifolia, Plantago rigida, and Vesicarex coZZumanthus. IsoZepis sp. (5603) grows closely associated with CZasmatocoZea vermicuZaris and BreuteZia chrysea. On the basis of ecological and floristical characteristi c s, this community belongs to the CaZamagrostion ZiguZatae, but with a clear affinity to the

Oritrophio-WernerietaZia. Synecology & distribution:

The stand is a local feature on the marshy, sloping thin (120 em) valley floor (3960 m) of the Lagunillas river in the Sierra Nevada del Cocuy. The hummocky patches are surrounded by flush vegetation of the Oritrophio-Wernerietum cotuZetosum (62b) . 60.

Superparamo vegetation with CaZamagrostis ZiguZata Fig.: 55

Our collections and h erbarium specimens indicate that Calamagrostis ligulata also is present in the superparamos of the Colombian Andes up to 4450 m.

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Homogeneous superparamo stands of this grass are scarce and poor in species. In the Sierra Nevada del Cocuy, huge hummocks of Calamagrostis ligulata occur along sandy lake shores between 4280 and 4430 m, generally associated with Ditrichum gracile and Agrostis foliata (see 109) and in some places with Calamagrostis aff. pisinna (8653). On the Nevado Ruiz (Central Cordill er a), at 4400 m, a Calamagrostis ligulata stand with an almost closed carpet of Bryum sp. was observed in a small depression draining moraines (Cleef et al.,in press). These data may indicate other associations of the Calamagrostion ligulatae which have not yet been described. In the upper condensation zone of the lower superparamo of the Nevado de Sumapaz a Calamagrostis ligulata community rich in species is present; it will be treated separately under the Bryo- Caricenion bonplandii (see 55cJ. Calamagrostis ligulata with low cover is found as a differenti a l species in the Carici- Wernerietum crassae (Oritrophic- Wernerietalia) in the superparamo of the Sierra Nevada del Cocuy between 4280 and 4430 m. Cuatrecasas (1934) reported Calamagrostis ligulata from the lower part (4320- 4400 m) of the superpiiramo on the volcano Nevco.do de Tolima, Cordillera Central. In conclusion is is evident that the Colombian superparamos contain at least three other syntaxa of the Calamagrostion ligulatae as yet remaining undescribed.

FLUSH VEGETATION AND CUSHION BOGS

WERNERIETEA cl. nov . (prov.) syn. Pl~taginetea Gutte 1980 (invalid name) type: Oritrophio - Wernerietalia (this study); table 13 lit.: Ruthsatz 1977; Cleef 1978, Gutte 1980; Cleef et al., in press (cited authors provide a survey of the pertinent literature) . Physiogomy & synecology: The flush and cushion bog vegetation of this class is dominated by geophytes, and low cushion chamaephytes. It comprises: I) hollow communities: e.g. flush vegetation, hollows at the edge of the firm hummocky bogs and between the vascualr cushions ; and 2) hummock communities of low matted or cushion-forming vascular plants and mosses. The fieldl ayer may contain small tufted grasses an dwarfshrubs , mai nl y a t lower elevations. Vascular plants cover 10-100% and bryophytes, mainly mosses, may cover 100% aquatic habitats and up to 75% on decaying cushions. The pH values of the root zone are 5'.'0- 6. 0 ; most of the cushion bogs are acid and the halophytic puna communities (Ruthsatz 1977) and 'waterlogged flush vegetation in the lower paramos are eutrophic. Soils are sandy and shallow in the highest areas and become clayey to peaty and thick in lower places. Slopes vary from 10째-20째. Composition. & syntaxonomy : Exclusive character species are Werneria pygmaea, Altensteinia paludosa, Plantago rigida, Distichia muscoides and Castilleja fissifolia ssp . pygmaea (ssp . nom. herb.; in ed.?). Thes e small forms of Castilleja fissifolia - Weddell ( 1857) referred to the name "pumila" are considered by the present author as a s ubspeci es of Castilleja fissifolia (if not a distinct species), Other character spec ies for the Wernerietea were listed by Ruthsatz (1977) and they include the species reported by her for the "Wernerion pygmaeae (prov.)", except LachemiUa pinnata . Gabrera (1958) mentioned Oxychloe andina (June.) from Argentinan high puna bogs, and

128

Weberbauer (1911) and Tovar Serpa (1973) listed Lachemilla diplophylla for the Peruvian, Ricardi & Marticorena (1966) for the northern Chilean Distichia cushion bogs. Finally all character species of the OritrophioWernerietalia and of its alliances and associations reported in the present study, are characteristic of this class. Oreobolus obtusangulus cushion bogs also occur in southern Chile. Oberdorfer (1960) ranked them under the Myrteola- Sphagnetea Oberd. The paramo cushions of Oreobolus (Cleef 1978) apparently belong to the same species and might be different from magellanic Oreobolus obtusangulus at the infraspecific level. Th e mean number of species is about 10-15 in 120 releves. The lowest averages have been found in the Argentinan puna stands and in the north Andean Wernerion crassae-pygmaeae, the highest averages in the cushion bogs of the Gentiano- Oritrophion in the bamboo paramos. Phytogeographically, the newly described class shows distinct australantarctic affinities which were earlier noted (Cleef 1978) 路. Details are provided below. The Wernerietea is floristically and ecologically well-defined and contains a good number of regional an lo cal character species and comprises flush vegetation and various successional stages towards vascular cushion bogs and their . phases of decay. The present diagnosis of the Wernerietea is somewhat tentative due to insufficient pertinent phytosociological data from the Ecuadorian, Peruvian. Bolivian and Chil8an Andes, and from cusion bogs with Oxychloe andina and Patosia clandestina in the southern high tropical Andes. Distribution: The Wernerietea communities occur along the high tropical Andes from Argentina and Chile to Colombia and Venezuela. Their distribution area corresponds roughly to that of Werneria pygmaea and includes also that of some small endemic tropical Andean juncaceous genera: Patosia, Oxychloe and Distichia. Its southern-most limit is the province of Mendoza in the Argentinan Andes; and the northern most limit is the Colombian Sierra Nevada de S. Marta. In the Colombian and Venezuelan paramos this class is found between 3400 and 4500 m, though at some locations up to 4700 m and 5200 m, resp. in the Ecuadorian and Bolivian Andes. Cabrera (1958), Hunziker (1952) and Ruthsatz (1977) reported similar communities from 3500 to 5000 m in the norhern Andes of Argentina.

ORITROPHIO - WERNERIETALIA order nov. type: Wernerion crassae-pygmaeae (this study); table 13 Physiognomy: Low matted herbs, predominantly geophytes and cushion chamaephytes, and/or mosses are most prominent. Liverworts have a rather limited cover. The ground layer contains vascular plants and/or mosses depending on edaphical conditions and altitude. The field layer is rather inconspicuous and covers only 10-25% or less. It consi sts of rale grasses, sedges and herbs. Dwarfshrubs may be common on cushion bogs with less vital cushions of vascular plants. Composition & syntaxonomy: Character species are Werneria pygmaea (select.) and Oritrophiwn limnophilwn (select.). Nearly exclusive character species of restricted geographical distribution in the north-andean paramos are e.g. Vesicarex collwnanthus, Erigeron paramensis, Werneria crassa, Floscaldasia hypsophila. Distichia muscoides and Plantago rigido are selective character species.

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The average numb er of species is IS (1-3 8) in 66 r e l eves; the lowest averages occur in the flush communities of the Wernerion crassae-pygmaeae, and the highest in the vascular cushion bogs of the Gentiana-Oritrophion. The Oritrophion- Wernerietalia compri ses all Andean paramo vegetation in flushes and vascular cushion bogs . The "Wernerion pygmaeae (prov.)" described by Ruthsatz (1977) from the NW Argentinan Andes must be considered as a geographical vicar i ant in the southern puna of the Cen tral and north-Andean

Oritrophio- Wernerietalia.

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Synecology: This order concerns flush or seepage areas and cushion bogs of vascular plants in the northern Andean paramos. The commun it i es occur in: I) small , steep val l eys 2) bo ggy glacial va lley floors including former lake floors . Th e substrate s ar e sandy-silty to clayey and peaty. The water table may be highe r than 10 em, l eve l wi th ,or, especially in the dry season, lowe r than the surface. The pH of the rootzone is 4.4 in cushion bogs and 7.2x i n flu s h vegetation. Mesotrophic conditions (pH 5-6) are common. The thickness of the soil varie s from 5 em to more than 120 em; on f ormer lake floors (e .g. in rel. 506, 507) more than 5 m has b een measure d. Generally, ho llow communiti es of the Wernerion crassae-pygmaeae preceed in time and space the cushion bogs路 of the Gentiano- Oritrophion. Mosses are important in the format ion of cushions, and again when the vitality of t he vascular cushions decreases (see Gentiano-

Ori trophion). Distribution: This order is present in all Andean paramos from Venezuela to Bolivia, and the area of distribu t ion corresponds to that of Oritrophium limnophilum, which is represented by s ome geographically vicari a ting subspec;ies. In the Colombian Cordillera Oriental the OritrophioWernerietalia is found from the upper forest l i ne to . the superparamo between 3400 and 4430 m. This vegetation was als o observed in the Colombian Cordillera Central between 3300 and 4500 m, in the Sierra Nevada de S. Marta between 3750 m and 4500 m and in the Sierra Nevada de Merida, Venezue la , b路e tween 3500 and 4400 m (Vareschi 1980 , Cleef unpubl . ) . Communities b e l onging to this order we re reported from Ecuadori an paramos between 3700 and 4700 m (Diels 1934 , Benoist 1935 , 垄llgaard & Balslev 1979) and from the Peruvian Andes (Weberbauer 1911, Tovar Serpa 1973 , Gutte 1980) Phy t ogeo graphi c comments: Character species of the Oritrophio-Wernerietalia show local and regional endism at the generic, specific and infra specific level s. According to Cuatrecasas (1969 and in litt . ) the morphologi cally variableOritrophium limnophilum is present with the ssp. nevadensis in the Venezuelan Si erra Nevada de Merida and in the Colombian Sierra Nevada d e S . Marta. Subspecie s mutisianum is found in the other Colombian and in the Ecuadori an paramos extending south into norhern Peru . From northern Peru to northern Bolivia the s sp. limnophilum and the ssp . punae (only Peru) are pres ent. Plantago rigida probably has about the same distribution as the last species and is a lso found in puna bogs (Tovar Se rpa 1973 , Gutte 1980) . Distichia muscoides does not reach Venezuelan paramos ; its NE limit is the Tama depression b etween the Sierra Nevada de Merida and the Colombian Cordill era Oriental. Vesicarex collumanthus occurs in the Colombian and Venezuelan high paramos. Floscaldasia hypsophila, according to Cuatrecas as (1979) is only known from the Cordillera Centr a l (Quindio, S. Rosa, Ruiz) and the Cordillera Orient a l (Sierra Nevada del Cocuy) of Colombi a.

130

Werner ia crassa is found with ssp. cr assa in the Colombian Cordillera Centra l and in Ecua dorian paramos, and with ssp . orientalis in the Cordillera Oriental of Co lombia (Quatrecasas 1980).

Erigeron paramensis is endemic to the northern paramos of the Colombian Cordillera Ori ental and in the Venezuelan Sierra Nevada de Merida. according to Pringle (1979), is found from Cost a Rica and Colombi a toward s s outhern Peru. Hypochoeris sessiliflora is known from the northern Andes from Venezuela to Peru and fr om Costa Rica . Hypsela reniformis (Campan.) is characteristic for the southern communitie s of this order .

Gentiana sedifolia

WERNERION CRASSAE- PYGMAEAE all. nov. t ype: Oritrophio limnophili- Wernerietum pygmaeae (this study ); table 13 Physiognomy: This alliance concerns ma inly low herbaceous-bryophy ti c flu sh v egetation . Sma ll , about 5-40 em high sedged and grasse s participate in formin g an open low field layer . Superparamo flush may locally l e ad to a bryophy tic- s edge pea t , up to 50 em thick . Composition & syntaxonomy: Character spec i e s are Wer ner ia crassa ssp . orientalis (exc l.) , Car ex peucophila (pref. ?) , Calamagrosti s planifolia ( se l.) , Lucilia pusil la (pref.) , Cotula minuta (sel . ) , Werneri a pygmaea (transgr.) and Ori t rophium limnophilum (transgr.) Aquatic bryophytes may be dominant , such as Isotachis s errulat a, Riccardia sp., Drepanocladus r evolvens , Scorpidium scorpi oides, Sphagnum cyclophyllum. The average number of species is 8 (1 - 3 1) in 36 releves . The abundance and higher cover of Werneria pygmaea (transgr . chara cter specie s) in the Wernerion cr assae- pygmaeae are dif fe r ential against the GentianoOritr ophion . In addition , the low average numb e r of species ( 8 in 36 r e leve s) of the Wernerion crassae- pygmaeae contras ts with the higher average (22 in 31 re,l eves) in the Gentiano- Oritr ophion . . Wer ner ia cr assa s sp. or ienta lis and Carex peucophila are character spec ies at hi gh a ltitudes . The endemic Werneria crassa spp . orientalis replace s Werneria pygmaeae on barren mineral soil in the superparamo flush of the Si e rra Nevada del Cocuy . Oritr ophium limnophilum h a s a higher cover in the s e communiti e s than in the cushion bogs

(Gentiano- Oritrophion) . Synecol ogy : The alliance concerns minerotrafent paramo flush vegetation wi th a pioneer character in moist valleys with continuously flowing ~mter . Habit a t s on damp soil and in hollows of vascular cushion bogs in valley floors and on forme r l ake floors . Differ ent kinds of substrates are present , depending on elevation and habitat, e.g . sand, silt , cl ay and peat. Peat or gy ttja occur in lacustric cushion bogs . The thi ckness of the substra te is 5 em in superparamo habitats and more than 120 em in peat . Root zone pH is 5 . 0-6 . 6 (7 . 0-7 . 2 of the water). This causes a mesotra fent to eutrafent paramo flush vege t a tion . Most superparamo habitats are mesotrophic, those in the lower paramos are eutrophic . Succession towards cushion bogs of the 'centiano-Ori t rophion may begin with flush vegetation of the Wernerion cr assae- pygmaeae. The grass paramo s t ands belonging to the last a lliance may be fringed with bluish cus hion grass meadows of Muhlenbergia spp . , covering damp soil in the transitiop toward s a dry vegetation (see 108) . In the highest located flush , a t about 4400 m, a sedge-moss turf may locally be d eveloped .

131

Distribution: The Wernerion crassae-pygmaeae is found in the paramos of the Colombian Cordillera Oriental from the upper forest line at 3400 m up to the superparamo at 4425 m. The alliance was also studied in the paramos of the Sierra Nevada de Merida, Venezuela, the Sierra Nevada de S . Marta, and the Colombian Cordillera Central . Details are listed under associations and subassociations. Werneria cr assa is restricted to Ecuadorian and Colombian paramos . 61.

Carici peucophiZae-Wernerietum crassae ass . nov. (prov . ) type: rel. 319; table 13; Fig. 54, 55 & 59

Physiognomy: The Carici-Wernerietum crassae concerns mainly s uperparamo flush vegetation; swamps of small low sedges and thin peat of sedges and moss e s, which are successiona l to flush vegetation. The following s trata can be distinguished: I) an open graminoid field layer with .10% cover, 2) a low sedge layer up to 10-15 em high, covering up to 90%, and 3) a low open geophytic or bryophy tic peat layer, up to 40 em thick . Composition & syntaxonomy: crassa ssp. orientaZis and Carex

Exclusive character spec ies are Werneria (syn . C. pinetorum Willd.; Dr.

pe~cophiZa

W. M. Weber, in litt . ) . Werneria crassa is a compact geophytic composite, endemic to the high North Andean paramos of Colombia and Ecuador. Its subspecies crassa in the Colombian Cordillera Central forms genuine cushion bogs (Cleef et al. in pres s ) . The population in the Colombian Estern Cordillera Oriental were recently distinguished by Cuatrecasas (1980) as the subspecies orientaZis, which is fairly common in the high paramos of the Sierra Nev ada del Cocuy (4000-4400 m). Populations were also found in lower area, in bogs and marshes in the Paramo del Almorzadero at 3850 m and at 3400 m in the Paramo de La Sarna, north of Lake Tota. Carex peucophiZa, on the other hand, is a polymorphi c species previously known from high locations in Mexico and Guatamala (Hermann 1974). The average number. of species in this association is 14 ( 4-31) in I 5 releves . The Carici-Wernerietum crassae is distinguished from the OritrophioWernerietum pygnaeae by the two character species (Carex peucphiZa~ Werneria crassa ssp. orientaZis) and some differential spe c ies: e.g. Isotachis serruZata~ Ditrichum gracile and scarce CaZamagrostis ZiguZata. Wermeria c路rassa ssp. orienta lis mainly replaces W. pygmaea in superparamo flu sh over mineral soil with an extremely low humus content. Werneria pygmaea is most prominent in the carice tosum peucophiZae, which occurs on peat or pea tcontaining soil. The floristic subdivision into two subassociations reflects ecological as we ll as succesional differences. Synecology : The stands occur in dry or marshy young moraine valleys in the superparamo of the Sierra Nevada de l Cocuy. The flush c onsists of a thin shee t of cold slowly flowing water containing filamentous algae and thallous live rworts . The compac t rosettes of Werner ia cr assa ssp. orientaZis with darkish-green leaves and with bright white rayflowe rs r emain just above the waterlevel. Vascular plants and bryophytes may cover up to 100%. Near the upper vegetation line , the number of species and the cover are considerably less due to harsh environmental conditions. The thickness of the clayey and sandy substrate under the flu s h vegeta tion varies from 5 to 100 em. The slope may be as steep as 12掳. Humus content of the upper soil layer, nearly absent in flu sh, becomes路路 more prominent under the l ow sedge-vegetation, which is mostly deve loped op peaty c l ay or fine

132

sand. The dense moss layer gradually prevents a proper drainage. Together with the cushion bogs of the FZoscaZdasio- Distichietum this turf belongs to the highest located bogs in the Colombian paramos . The pH is 5.0-5.6. Distribution: The association is described from the high areas on the SW side of the Sierra Nevada del Cocuy. Releves are located in the upper grass paramo at 4125 m and the superparamo up to 4425 m. Werneria crassa vegetation was studied locally in lower places (3400-3850 m) between Lake Tota and the Paramo del Almorzadero. The Caraci-Wernerietum crassae is re estricted to the Colombian Cordillera Oriental (depts. Boyaca, Arauca, Santander). 61a.

Subass. wernerietosum crassae subass. nov. prov . type: rel. 319; table 13 ; Fig. 59 lit .: Cleef 1978

Physiognomy: The superparamo flush vegetation of this association is dominated by geophytes and hemicryptophytes. Thallous liverworts are predominant in the ground layer in aquatic habitats . Peat is hardly or not present. Composition & syntaxonomy: Werneria crassa ssp . orientaZis, PiZopogon sp. nov. (5881, 8598), Senecio fZos-fragrans var . frigidophiZus are differential species. Riccardia is predominant in aquatic stands; Ditrichum graciZe on humid soil. Oritrophium ZimnophiZum ssp . mutisianum is present with tall fleshy broad-leaved rosettes, which are typical of high altitudes in the Sierra Nevada del Cocuy. The average number of species is 9 (4-16) in 7 superparamo releves; the lowermost stands contain 28-31 species. This subassociation comprises all superparamo flush communities with Werneria crossa ssp. orientaZis, including some isolated patches in lowP.r places of the variant of Lysipomia sphagnophiZa ssp. minor (61aa). Werneria crassa ssp. orientaZis is absent in rel. 320, but this stand is included here, as it has a similar floristic composition and occurs at a similar site. Rel. 316 and 335 might represent a variant of Carex peucophiZa. Synecology: The superparamo flush of the wernerietosum crassae occurs in wet or humid valleys in young moraine areas, which have been ice-free during the last 200 years (Vander Hammen et al. 1981). Seils are clayey or sandy; and about 100 em thick. The pH is 5.1-5 . 6 in the upper rootzone. Distribution: The wernerietosum crassae is restricted to the northern paramos of the Colombian Cordillera Oriental, where it is mainly found in the superparamo of the Sierra Nevada de~ Cocuy between 4125 and 4415 m. Stands are scarce near the lower limit of the grass paramo (3400 m) . 61aa. Variant of Lysipomia sphagnophiZZa ssp . minor var. nov. type: rel. 382; table 13 Physiognomy: This type of flush vegetation of the lower paramo contains many low herbaceous species (cover 60-90%), including scarce bunchgrasses, the culms of which are 100 em high. The moss layer is about 10 em thick, and the cover is 25-50%. Composition & syntaxonomy : The vegetation of thi~ variant is rich in species. Differential taxa are Sphagnum cycZophyZZum, DrepanocZadus revoZvens,

J 33

CaUiergon stramineum, Lysipomia sphagnophila ssp. minor (= L. obZiqua Wimmer), Hypochoeris sessifZora (white rayflowers), Plantago rigida, BreuteZia aZZionii, Hypericum Zancioides, Festuca cf. doZichophyZZa, Xyris acutifoZia, DipZostephium revoZutum, Sphagnum sancto-josephense, Leptoscyphus cZeefii and a reddish species of Odontoschisma. There is a strong floristic and ecologic affinity with Sphagnum bogs and cushion bogs (Hyperico-PZantaginetum), which are in contact with each other at this altitude. The presence of Werneria crassa ssp. orientaZis in the lower paramo is another example of a superparamo taxon occuring in a lower zone in bogs, reedswamps, mires and flush vegetation. See also under the Marchatio-

EpilobietaZia. Synecology: Slowly drained boggy valleys with peaty clay (pH about 5.0). The phreatic table is near surface. Small frogs (e.g. AteZopus ebenoides marinkeZZei; det. Dr. P.M. Ruiz-C., Bogota) and black leeches are common. Distribution: Flush vegetation of this variant was studied in the Paramo de la Sarna, N of Lake Tota in the subparamo-grass paramo border at 3400 m. Another stand was observed at 3900 m in the Paramo del Almorzadero. Subass. caricetosum peucophiZae subass. nov. (prov.) type: rel. 314; table 13; Fig. 54, 55

61b.

Physiognomy: This subassociation concerns peaty depressions in the superparamo with a mat of liverworts or moss peat. Small low vascul?r species of a geophytic nature cover 40-100%. The graminoid field layer is inconspicuous Composition & syntaxonomy: Carex peucophiZa andbryophytes, mainly Isotachis serruZata and CampyZopus cf. incertus (8593), are prominent. The endemic FZoscaZdasia hypsophiZa (Comp.) is a common differential species. The average numbers of species is 12 (8-22) in 6 releves. Differential against the wernerietosum crassae are the presence and high cover of Carex peucophiZa in combination with the absence of Werneria crassa ssp. orientaZis. On peaty substrate the latter is replaced by Werneria

pygmaea. Synecology: The vegetation concernspeatyvalleys in young superparamo moraine areas, adjacent to wernerietosum crassae. In the upper P?rt of the sloping flat valley floors,a local vegetation of low sedges and bryophytes is developed into a thickness up to 40 em CampyZopus peat on mineral soil; pH of the water perculating in the peat 5.4-7.0. The substrates are peaty sand and c Vay, in places covered with mossturf.

Distribution: The caricetosum peucophiZae is only known from the superparamo of the Sierra Nevada del Cocuy, between 4250 and 4425 m. 61bb. Variant of CampyZopus aff. incertus var. nov. (prov.) type: rel. 321; table 13 Physiognomy: The vegetation of this variant concerns superparamo moss turf with geophytes. Small sedges may cover up to 90% (see for comparison Vareschi 1980, Fig. 130).

134 Composition & syntaxonomy: Diff er ential species are CampyZopus aff. incertus ( 8593 ), Fossombronia sp. (8587) and Bartramiaceae viz. PhiZonotis sp ., Conostomum pentastichum. FZos caZdasia hypsophiZa and LachemiZZa mandoniana are present in both r eleves . Th e numb er of s pec ies is 15 and 22 in the two releves. The variant can be easily reco gni zed by the differential species and the pres ence of moss turf. Synecology: Patches, up to 40 em thick, of mossy peat on minera l soil in tQ~ u??e r end of moist superparamo valleys. The pH of the water in rel. 320 -"â&#x20AC;˘i1 s" 7.0. This kind of peat, probably is palynologically most revealing for the las t 100 - 200 years. Together with vascu l ar cushions of Distichia muscoides the patches represent the highest located paramo bogs. Di stribution: This vegetation is only found at high altitude in the superparamo of the Sierra Nevada del Cocuy, between 4400 and 4425 m in the Paramo C6ncavo. Bogs of similar nature and under similar ecological condi tion s, but with a different compos ition, were studied in the Vene zuelan Sierr a Nevada d e Merida at 4 125 m and 4400 m (Vares chi 1980), in the Parque Lo s Nevados in the Colombian Cordillera Central at 4400 m (Cleef et al., in press) . 62.

Oritrophio ZimnophiZae-Wernerietum pygmaeae ass. nov. type: rel. 39; tabl e 13; Fi g.: see under subassociations and variants

Phys io gnomy: Thi s bryophytic and low herb aceous flush vegetation is characte ri zed b y weak stratification viz. in lowermost moss l ayer (5 em th ick) and a he rbaceous upper l ayer up to 15 em. Herb cover is generally more th an 50% and is highest in the cotuZetosum . Average moss cover in the l as t subassociation i s only 20% but reaches 15% in the subassociat ion

typicum . Composition & syntaxonomy: The chara ~ ter species Werneria pygmaea (transgr .) is present in each r e leve, and has high cover (average 45% in 20 releve s ). This is differential against al l other syntaxa of the c l ass. Seve ral species of hydrophytic mosses are prominent, and one of the following aqua tic species may be dominant: Scorpidium scorpioides , Sphagnum cycZophyZZum, DrepanocZadus revo Zvens , and in some places FontinaZis bogotensis. Liverworts are nearly ab sent. Tiny herbs are CotuZa minuta, Car ex cf. grandifZora , RanuncuZus f ZageZZiformis, R. nubigenus, LachemiZZa mandoniana,

EZatine chiZensis , Juncus cyperoides , EZeocharis stenocarpa, Scirpus (IsoZepis) inundatus and Vesicarex coZZumanthus . The average numver of species is 7 (1-15) an is sligh tly higher in the cotuZetosum than in the subass. typicum. CotuZa minuta is a diff er ent i a l spe c ies, and is found op timally in the cotuletosum . Elatine cf. chilensis and EZeocharis stenocarpa are companions in thi s associa tion . The latt er species may be locally replaced , e.g. by

RanuncuZus fkageZZiformis ( a local facies). The present subdivision of the association is based on the presence of CotuZa minuta together with other s~all herbaceous species as Carex cf. grandifZora,RanuncuZus spp., Vesicarex coZZumanus, Agrostis brevicuZmus, Juncus cyperoides, EZeocharis stenocarpa. Syneco logy: The habitat of the Or i trophio- Wernerie tum pygmaeae is found in bo ggy depressions , rills, hollows of vascular cushion bogs, drainage areas in paramo mire and bogs, and in small sloping valleys with stagnant or

135

almost permanently slowly running water. Slopes are up to 7째. Substrates are clayey to peaty. The highest proportion of the peaty componentis generally found in lower areas in the flush habitats. The pH of the rootzone in 9 releves indicates eutrophic conditions, with values from 6.1 to 6.6 (5.0-7.2). Soil thickness is 40 em to more than 120 em. Thick peat and gyttja are present on former lake floors (rel. 506, 507). Most of the soils are black (clayey to peaty) in the upper part, passing downward into a grayish clayey layer, with a gravelly base on (sandstone) bedrock or moraine sediments. Some small cushions of Plantago rigida were found in the Oritrophio-Wernerietwn pygmaeae. They initiate the succession towards the vascular cushionbog of the Hyperico-Plantaginetwn rigidae. Hirudinae and Gammarus sp. are common. Some frogs have been observed .. Sylvilagus, Cavia and cattle are frequent in the stands in the lower paramos. Distribution: In the Colombian Cordillera Oriental this association is found from the upper forestline up into the superparamo at 4425 m. It is most common in the grass paramo and upper subparamo. The OritrophioWernerietwn pygmaeae is widely distributed in the high tropical Andes. Unfortunately, very few data are available on its phytosociological characteristics in other regions . 62a.

Subass. typicwn subass. nov. type: rel. 346; table 13; (Fig. 42; see also under variants)

Physiognomy: This low bryophytic and herbaceous vegetation is mostly found in shallow and slowly running water. Most herbs grow as helophytes, the mosses remain submerged. Composition & syntaxonomy: The character species of the order, Werneria pygmaea, Oritrophiwn limnophilum ssp. mutisii and Vesicarex collumanthus are prominently present in this subassociation. Aquatic moss species are e.g. Sphagnum cyclophyllum, Drepanocladus revolvens and Scorpidiwn scorpioides. The average number of species is 6 (1 - 9) in 13 releves. The subassociation typicwn can be readily distinguished by the conspicuous (aquatic) moss cover, which is differential against the co tuletosum . In addition, the absence of Cotula minuta and the lower number of species, average 6 versus 10 in the cotuletoswn, are differential. The subassociation is subdivided into 5 variants, which are based on the composition of the moss cover. This community is ranked at the variant level and not regarded as a local facies, since field observations revealed that it is a feature of genera..l occurrence. On the strength of our observatio.ns and of herbarium data, a var i ant of Drepanocladus exannulatus is distinguished as a hollow community in the Floscaldasio-Distichietwn between 3800 m (Purace) 'and 4250 m (S. Nevada del Cocuy). Synecology: Flush vegetation in the high paramo usually with runoff water. Four mossy variants can be distingu~shed on the basis of specific mostly edaphic - habitat factors. One of these is the hollow phase in cushion bogs of the HypericoPlautaginetwn rigidae on former lake floors. Mosses are absent in superparamo stands on silty to gravelly clay on the dry side of the mountains. The pH of the clayey to peaty upper part of the soil is 5.0-6.6. The slopes are up to 7째.

136

Distribution: The subassociation typicum of the OritrophioWernerietum pygmaeae is common throughout the high paramos of the Colombian Cordillera Oriental between 3700 and 4425 m, and has also been studied in the Cordillera Central and the Sierra Nevada de S. Marta, where it is found at the same heights . Some releves between 4050 and 4150 m from the Sierra Nevada de Merida, Venezuela, contained a not yet described variant of cf. CaZZiergoneZZa cuspidata (differential species), while Vesicarex coZZumanthus was found with a higher cover (up to 70%). The subassociation typicum is expected to be widely distributed in the high tropical Andes 62aa. Variant typicum var. nov. (prov.) type: rel. 450; table 13; Fig. 54 photo: Cleef 197&, photo 173 Physiognomy:

See subassociation typicum.

Composition & syntaxonomy: This type of flush community is poor in species (1-3 species in each releve). Werneria pygmaea and fleshy broadleaved rosettes of Oritrophium ZimnophiZum ssp. mutisianum (fma ., e.g . 8582), are common. Algae may be present, but bryophytes are virtually absent. This high altitude variant is characterized by the absence of differenti a l species (against other communities of the Oritrophio-Wernerietum pygmaeae). Synecology: These superparamo flush communities are found in young moraine valleys on a thin clayey to silty or sandy to gravelly substrate The habitat is rather unstable as a result of intermittent deposition of sediments. The stands are common at the edge and in hollows of the cushionbogs of the FZoscaZdasio-Distichietum. Distribution: This vegetation type has only been studied in the Sierra Nevada del Cocuy, from the highest places in the upper grass paramo up into the superparamo between 4200 and 4425 m. The variant was found also in the superparamo of the Colombian Cordillera Central. 62ab. Variant of BreuteZia Zorentzii var. nov. (prov.) type: rel. 289; table 13 The differential species BreuteZia Zorentzii and Rhacocarpus purpurascens cover almost entirely the surface. Ourisia muscosa3 BreuteZia Zorentzii and BrachioZejeunea securifoZia are common here and elsewhere in the upper condensation zone of the Nevado de Sumapaz. A sequence of clayey and sandy laye rs with a clayey top is present, covering a presumably former lake sediment. Small patches of this variant were only observed in the upper reaches of the Nevado de Sumapaz . 62ac. Var. ofSphagnum cycZophyZZum var. nov. type: rel. 39; table 13; Fig . 56 (also Fig. 75) Physiognomy:

Similar as the subass . typicum.

Composition & syntaxonomy: Sphagnum cycZophyZZum, a holarctic species has a cover of 40-95%, and is differential against the other variants . The shallow , slowly flowing water contains also Isoetes novo-granadensis and spherical blue algae. Synecology: This type of grass paramo flush vegetation is found on thin clayey soils (pH 6.3 in rel. 39).

J37

Distribution : This variant was studied in the highest areas of the bamboo paramos only in the Paramo de Guantiva and the Paramo de Sumapaz between 3800 and 3900 m. 62ad . Variant of Drepanocladus revolvens var . nov . type : rel. 506 ; table 13 ; Fig. 57 Physiogromy & syntaxonomy : Werneria pygmaea or dark greenish rosettes of Oritrophium limnophilum ssp. mutisianum are the most conspicuous vascular plants , covering about 50% . An almost continuous carpet of Drepanocladus revolvens, a moss species common in temperate bogs, is found under the rosettes . Drepanocladus revolvens is the differential species. Synecology : The variant of Drepanocladus revolvens is found in hollows in vascular cushion bogs of the Hyperico-Plantaginetum rigidae covering former glacial lake floors . The soil is thick and consists of Plantago rigida peat , at least in the upper part . Distribution : The variant is only known from former glacial lake floors on the Andabobos watershed at 3725 m, in the humid Paramo de Sumapaz . 62ae . Variant of Scorpidium scorpioides var . nov . type : rel . 346 ; tabel 13 Physiognomy & syntaxonomy : This variant concerns flush communities with a high cover of Werneria pygmaea and Scorpidium scorpioides (25-100%; average 65% in 5 releves) . Scorpidium turfaceum Herzog from the Bolivian high Andes is co~sidered as a synonym of the cool , wide temperate Scorpidium scorpioides. Vesicarex collumanthus is a common associated species . For further physiognomical data , see the subassociation and association . Differential against other syntaxa of the association is the conspicuous moss carpet of Scorpidium scorpioides . Flush vegetation (rel . 570), reported by Aguirre et al . (in press) from the Paramo del Almorzadero at 3900 m with Eleocharis stenocarpa (100% cover), Scorpidium scorpioides (80% cover) and lax plants of Colobanthus quitensis (less than 1% cover) probably also belong to this variant . Synecology : The flush communities of this variant are present in wet high paramo valleys (slopes up to 5째). One pH of 6 . 6 was measured in the yellowish-brown clayey to peaty rootzone in rel . 346 . In the dry period the stand may temporarily dry out. This variant is present also in the hollows of Distichia cushion bogs . Distribution : The variant wa's' recorded from all hign grass paramos of the Colombian Cordillera Oriental between 3800 and 4275 m, and just reaches the lower limit of the superparamo 62b .

Subass . cotuletosum minutae subass . nov . type : rel. 186 ; table 13; Fig . 70 (also Fig . 12 , 13)

Physiognomy : The paramo flush vegetation of the cot?<letosum, is dominated by low herbaceous species, either rosette plants or sedges, up to 15 (25) em high . The herbs have a cover of ahout (80) 95-100%, whereas the moss cover is generally less than 50% .

138

Composition , phytogeographical notes & syntaxonomy : Cotula minuta is a differential species in all releves,together withisolepis inundatus,Carex cf . grandiflora and Juncus cyperoides . Eleocharis stenocarpa and Ranunculus flagelliformis most likely represent differential facies , l:ut this remains to be proved. Cotula minuta is widely distributed from Mexico , northern Argentina and Chile, and has been collected in Colombia between 2700 and 4000 m. It is a differential species for the Marchantio-Epilobietalia of which Ranunculus flagelliformis is a widely distributed character species in cool tropical America (Lourteig 1956) . Isolepis (Scirpus) inundatus is a widely distributed temperate species. Eleocharis stenocarpa is restricted to the northern tropical Andes from Venezuela to Ecuador,from the warm tropical interandean valleys at 600 m up to 4000 m.Juncus cyperoides occurs from Central Chile to the Colombian Andes. (Balslev 1979) , in the Paramo del Almorzadero reaching its northernmost location known at pres ent. The number of species is 10 (4-14) in 8 releves . Cotula minuta is locally replaced by Carex cf . grandiflora sp . (7365) , which may be dominant. This small sedge species also occurs in the HypericoPlantaginetum rigidae. The local high cover of Eleocharis stenocarpa represents a facies. Synecology: Peaty meadows of the c路atuletosum are present on glacial valley floors with eutrophic flush on brownish-black clayey peat , mostly thicker than 1 m. At the base it passes into a blue-grayish clayey layer, generally overlaying the bedrock . The pH of the water is 5 . 8-6.5 (-7.2). The watertable is mostly near surface . The slopes are up to 3掳. Distribution : The dotuletosum has only been studied and observed between 3500 and 3925 m in the lower grass paramo in the northern part of the Colombian Cordillera Oriental . The highest records are from the dry side of the mountains bordering the deep and dry inter-andean Rio Chicamocha valley.

GENTIANO - ORITROPHION all . nov . (prov.) type : Hyperico lancioides- Plantaginetum rigidae (this study) ; table 13 Physiognomy : The paramo cushion bogs are mainly dominated by low chaemaephytes . Cushion plants are species of Juncaceae, Cyperaceae and Plantaginaceae . Bryophytes may cover a considerable part of the cushion; ofther vascular elements (dwarfshrub, grasses and. low herbs) have a moderate cover .

139 Composition & syntaxonomy : Character species are Castilleja fissifolia ssp. pygmaea ( excl.), Gentiana sedifolia ( sel.), Altensteinia paludosa ( sel.) , Lycopodium "cruentum-attenuatum complex" (sel.) Calliergon sarmentosum (sel.) and those of the corresponding associations . Differential against the Wernerion crassae-pygmaeae are Breutelia allionii, Campylopus cavifolius, Hypericum lancioides, Bartsia sp(p~, Nertera granadensis, Pernettya prostata, Calamagrostis effusa and Cortaderia cf. sericantha. The average number of species is rather high, about 22 (8 - 38 in 31 releves) against 8 (in 36 releves) for the Oritrophio-Wernerion. The alliance is well defined by several character and differential species. Werneria pygmaea and Oritrophium limnophilum have a low cover and are not abundant. The more stable Gentiano-Oritrophion has a higher average number of species than the more unstable Wernerion crassae-pygmaeae due to extreme environmental conditions . The differential species for this alliance also occur in the zonal paramo vegetation, most of them in the boggy Swallenochloa tesselata - bamboo paramo. Further subdivision is based on floristic differences and altitude. Synecology: This alliance concerns moist valleys and former filled up glacial lakes that have been in the paramo belt . Some cushions also are floating on lakes, others are found on damp slopes, at the edge of bogs and swamps in the zone transitional with the zonal paramo vegetation, and in the upper condensation zone. Cushions are soligenous and ombrogenous , the latter occur in the highest places of deep bogs completely depending on atmospherical humudity (fog, precipitation).Substrates are thick clayey peat or gyttja, but cushions are also found on sloping clayey soils or on barren gravelly or coarse to sandy glacial deposits. Slopes are up to 8째 . The paramo cushion bogs are generally mesotrophic (pH 5- 6). The Oritrophio-Oreoboletum is typical for oligotrophic conditions (pH 4.8 - 5 . 1) . Distribution : The Gentiano-Oritrophion is found between the subparamo ( 3150 m) and the lower superparamo ( 4350 n ) of the Colombian Cordillera Oriental. The alliance is also known from the Sierra Nevada de Merida, Venezuela, and from the Colombian Cordillera Occidental (Hyperico - Plantaginetum rigidae only) and the Colombian Cordillera Central (Floscaldasio-Distichietum, Hyperico-Plantaginetum rigidae). Details are presented under associations . The alliance seems to be absent in the Costa Rican paramos. Its southernmost occurrence is in the Peruvian and the Bolivian Andes . Phytogeographical and physiognomical relationship As pointed out before (Cleef 1978) , the paramo cushion bogs floristically and physiognomically have a distinct austral-antarctic affinity. The paramos of the Colombian Cordillera Oriental are the northernmost American mountain areas containing all three described associations . As stated by Balslev (1977 , 1979) , Distichia tolimensis is a synonym of D. muscoides and the main region of distribution of this genus is the Bolivian Andes, also co~taining the endemic

D. filamentosa. Plantago rigida according to Rahn (1978) belongs to the southern hemisphere section Oliganthos of Plantago subg. Plantago. From Ecuadorian paramos and southward there is another cushion-forming species of this section, Plantago tubulosa 8cne., in high Andean bogs and on damp soil; however, this species does not become predominant .

Oreobolus cushion bogs are widely distributed in the temperate southern hemisphere and in pacific tropical high mountains (Godley 1978) . Oreobolus obtusangulus bogs were only reported from southern S. America, the Islas Malvinas and Masafuera, and the paramos of the Colombian and the Ecuadorian Cordillera Oriental.

63.

FZoscaZdasio - Distichietum muscoides ass. nov. type: rel. 355; table 13; Fig. 58 (a lso Fig. 28, 32, 55) lit.: Cleef 1978, Gutte 1980 photo: Cleef 1978, photo 171-17 3; photo 172 shows the type locality

Physiognomy: The vegetation consists of high paramo juncaceous cushion bogs dominated by low chamaephytes. Most of the associated vascular plants are low herbaceous species; the pale graminoid fieldlayer is up to 10 em high. Patches of moss es up to 30 em thick may cover the greater part of the decaying Distichia cushions. Composition & syntaxonomy: Distichia muscoides is a regional exc lusive character spec i es from No rth ern Argentina and Chile to Colombia. The endemic FZoscaZdasia hypsophiZa is a regional se lect i ve character species, as it is restricted to the high paramos of the Sierra Nevada del Cocuy and the high Rui z-S. Isabel volcanoes in the Colombian Central. LachemiZZa mandoniana is a characteristic constituent with high frequency in Distichia bo gs . LachemiZZa sp. and L. nivaZis are locally common . The FloscaZdasio- Distichietum is defined by both its character species mentioned above in combination with character species of the Gentiano- Oritrophion and the Oritrophio- WernerietaZia. The number of species is considerably variable and is highest on the humid side of the mountains. Low values are generally recorded for I) young and firm cushions, 2) stands on the dry side of the mountains and 3) near the uppermost location of the cushion bogs. The average number of species is 20 (8- 38 in 4 releves). In stands in the atmospherically rather dry paramos of both the Cordillera Central and Oriental of Colombia the average number of species is about 10. The Distichia bogs at Patio Bolos , Sie rra Nevada del Cocuy contain some species that are lacking in other kinds of cushion bogs, e.g. CampyZopus subjugorum~ C. aerodictyon~ C. heterostachyus and PhiZonotis sp. (8915) . Shrub of Senecio fZos-fragrans var. frigidophiZus is locall y present on the decayed hummocks. Synecology: The FZoscaZdasio- Distichietum comprises the highest located cushion bog of vascular pl ants in the Colombian paramos. The cushions occur in moist valleys and may cover former lake areas. Slopes are up to 7째 and the peaty substrate under the uppermost cushions is thin to more than 300 em. A cyclic sequence of peaty (mainly r emains of Distichia) and c l ayey layers is common in the boggy superparamo valleys. Gravelly deposits are overlain by clayey sediments passing into peat when the water falls. These phenomena may partly be correlated with major climatic changes . Peat in the FZoscaZdasio- Distichietum bogs is mesotrophic with a pH of 5.1 - 6.3 in the upper laye r. The Distichia hummocks on the humid side of the mountains are sooner decaying than those on the dry side, as indicated by mosses. Additional synecological data were presented earlier (Cleef 1978). Distribution: This association has been studied between 3800 and 4300 m in the upp er grass paramo and lower superparamo of the northern part of the Colombian Cordillera Orient a l. Distichia cushions are common her in the high grass paramo and were reported from the Sierra Nevada de l Co~uy and adjacent western and southwestern paramos, the Paramo del Almorzadero, and from the paramos de S. Urban and Vegas abou t 7째 N, which seems the northernmost location of Distichia muscoides . cush ion bog in America. During more than 3 months fieldwork in the northern and central part of the Paramo de Sumapaz Distichia cushions have not been observed. They a re also absent in the paramos of the Sierra Nevada de S. Marta an the Sierra Nevada d e Merida, Venuzuela, and were never reported from the Colombian Cordillera Occidental and Costa Rica. In the Colombian Cordillera Central the FZoscaZdasio- Distichietum has been studied between 3800 and 4500 m (Cleef et al, in press). According to Balslev (1979), Distichia muscoides occurs

141 in the Ecuadorian paramos between 3600 and 4700 m. The southern boundary of this paramo association coincides with that of a combination of different character species, which may extend as far as the Ecuadorian or the northern Peruvian high Andes. 64.

Community of Distichia muscoides with Cortaderia sericantha and Campylopus

cf fulvus. table 13; Fig. 59, 60 photo: Cuatrecasas 1958: plate XXII-2; idem 1968: fig. 8. Physiognomy: These are probably floating cushions of vascular plants on a partly filled-up glacial lake in the upper bunchgrass paramo .. Characteristic large grass tussocks with a cover of 5 - 15%. The graminoid fieldlayer contains also sparse composite dwarfshrub (40-130 em) with a cover of 15%. The bryophyte layer is about 3-5 em thick and covers 10 - 25%. Composition & syntaxonomy: The community contains some species, that are scarce to absent in the Floscaldasio- Distichietum, e.g. Cortaderia sericantha,

Isotachis serrulata, Campylopus cavifolius, Calamagrostis effusa, Pseudocephalozia quadriloba, and the rare Symphyogyna digitisquama (Vander Grande 1980). The average number of species is 16 (10-20) in 3 releves. The community has not yet been assigned to a syntaxonomical rank, because it was only observed in one locality and character species of the order and some of the alliance are absent, e.g. Breutelia allionii. This vegetation type is more or less intermediate between the Hyperico-Plantaginetum rigidae and the Oritrophio- Oreoboletum, but its position may also be close to the Floscaldasio - Distichietum. Synecology: This community has only been studied in one former glacial lake , in a location lower than that of the Floscaldasio- Distichietum . The Distichia cushions may be in root-contact wi th the lake bottom g yttj a . They are most conspicuous where the cushions are fused. When Distichia dies off, algae, Riccardia sp. (8745) and Floscaldasia hypsophila appeaJ;, later followed by Bartsia sp., Hypericum lanciodes, Campylopus cavifolius, Senecio flos-fragrans var. frigidophilus and species of Cladonia subg. Cenomyce . In open water Werneria crassa ssp. orientalis is found between the cushions together with purplish cf. Microspora, Isotachis serrulata and some Ditrichum sumersum. Oreobolus obtusangulus hummocks locally replace Distichia cushions and may have a cover of 25%. The moss Calliergon trifarium and the liverworts Pseudocephalozia quadriloba and Cephalozia dussii are common on the wet Oreobolus hummocks. The pH of the water is 5.1 - 5.4.

Distribution: This community is only known from the Bocatoma valley at 4100 m in the Sierra Nevada del Cocuy. It was studied tfiere in a nearly filled -up former glacial lake between lateral moraines covered by open Calamagrostis effusa grassland characteristic for the upper bunchgrass paramo. Note: Gonzalez et al. 1965 published a pollendiagram for Lake Bocatoma (VL IX, plate 7).

142

65.

Hyperico lancioides - Plantaginetum rigidae ass. nov. type: rel. 410; table 13; Fig.: see under subassociations photo: Cleef 1978, photo 167-170 (photo 167 shows the type locality) lit.: Cleef 1978; Gutte 1980; Cleef et al., in press

Physiognomy: These are grass paramo bogs of firm, young cushions associated with only a few other species, e.g. Isoe t es andina. Smalle geophytes are common, e.g. Altensteini~ paludosa, Hyp ochoeris sessiliflora, Werneria pygmaea, W. humilis var. angusUfolia, Eryngium humile, Geranium confertum, Is oetes andina. Many other herbaceous species including grasses are present as •rell. In addition, sparse dwarfshrubs, e.g. Hyperi cum lancioides (up to 30 em high), b.ryophytes and lichens are present in greater numbers on older, less vital and decaying cush i ons. Note: The Plantago rigida plants flower in the dry season, from november march. Composition & syntaxonomy: Plantago rigida is an exclusive character species. Regional character species at least for the Colombian Cordillera Oriental are Gentianella nevadensis (select.), Lysipomia sphagnophila (pref.) and Isoetes andina (pref.). Differential ~pecies are Geranium confertum, Hypochoeris s essiliflora (both with white and yellow ligulae), Carex tristicha with some other stil l unidentified tiny sedges (e.g. 2584, 7365), Juncus

cyperoides, Eryngium humile, Chorisodontium speciosum, C. wallisii, Bidens triplinervia, Baccharis tricuneata, Halenia sp. (7505). Luzula vulcanica, Lachemilla hispidula (?), Drepanocladus r evolvens, Hookeriopsis sp. (4414), Campylium chrysophyllum (rare) and Breut elia tomentosa may occur in the altitudinally lowermost stands. The average number of species is 25 (18-38) in 14 releves. Actually this .will be slightly higher, because, in 6 releves the cryptogamic inventory was incomplete. This association is best characterized by presence and dominance of its only exclusive character species Pl antago rigida This associat{on is distributed throughout the large northern tropical Andean distribution area of its character species. In the paramos of the Colombian Cordillera Oriental, two subassociations can be distinguished, one of which mainly 6n the dry side of the mountains, this subassociation has also been studied in the, Venezuelan paramos of the Sierra Nevada de Merida. The other subassociation prefers the humid and wet side of the mountains and is supposed to extend far south as Chachapoyas, Norhern Peru, on the Amazonian side of the high Andes. This subdivision not ·only reflects differences in floristics, cover and even succession between both subassociations, but also climatological differences. Cushion bogs of limited size with fiTm hummocks occur on the dry side of the mountains (gentianelletosum), more and larger stands of the breutelie tosum on the humid side, where Plantago cushions were found varying from vital to decaying. The Plantago rigida cushions in the we t paramos are probably highly sensative to decay. The firm c ushions of the gentianelletosum in the climatologlcally dry paramos seem to be very persistent. The process of decay is not yet known, but other vascular species may play there in. Recent fieldwork in the paramos on th e volcanoes S. Isabel and Ruiz in the Colombian Cordillera Central indicated th~ presence of another not yet described.subassociation of the Hyperico-Plantaginetum rigidae, character~zed by tall tufts of grasses (Festuca sp., Agrostis sp.) and by herbaceous species ~s Niphogeton lingula, Lupinus sp., Gentianella dasyantha etc. (Cleef et al. ~n press).

143

In the southern Plantago rigida cushion bogs in Peru and Bolivia, additional new syn taxa can be exp e cted. Releves from there , as recently published by Gutte (1980) may provide more information on the phy t osociological position of the Plantago rigida cushion bogs and their ecology. Synecology: In the visited paramos of the Cordillera Oriental cushion bogs of the Hyperico-Plantaginetum rigidae occur:!) in smal l and sloping boggy valleys; 2) on the boggy floor of U-shaped glacial valleys; 3) in bogs on former lake-floors; 4) floating on de ep glacial lakes, and 5) in the lower superparamo, if the upper condensation zone is well developed. The slopes a re up to 10Â° , the thickness of the peaty to clayey or gyttja sediments under the Plantago rigida cushions is about 10 em (in soligenous superparamo stands and more than 5 min former lake-floors. Reduction-oxydation colours are common in profiles of soli genous bogs. The pH immediately under the cushions is 4 . 4-6.4, indicating mesotrophic condi.tions. Exceptional eutrophic values (pH 6.2-6.4) were measured in a soligenous bog on coarse sandy to grave lly calcareous substrates on the Nevado de Sumapaz (rel. 275), and in the Paramo de la Rusia (rel. 254, 263). For additional synecological data see Cleef (1978) . Distribution: According to the authors listed by Cleef (1978), Plantago rigida cushion bogs occur in the tropical high Andes from Bolivia to the Sierra Nevada de Merida, Venezuela, between 3000 and 5200 m. In the Colombian paramos they are found between 3400 and 4280 m, but optimally developed between 3800 m and 4100 m. From the Colombian Cordillera Occidental there is only one report of Plantago rigida. Pennell collected it (10.579-US) on Cerro Tatama betwe en 3400 m and 3700 m. Plantago rigida cushion bog seem to be s c arce in the Sierra Nevada de S. Harta, where it seems to be r eplaced by an Azorella crenata cushion bog (rel. 531), at least on the humid NW.side of the mountain . 65a.

Subass. gentianelletosum nevadensis subass. nov . t ype : rel. 410; table 13 ; Fig. 61 (also Fig. 12 , 72) photo: Cleef 1978,photo 167 shows the type locality Phys iognomy: These are bunchgrass paramo cushion bogs. Low herb speci e s are common, bryophytes r a ther scarce.

Composition & s yntaxonomy: Differential species are Gentianella nevadensis a nd G. corymbosa, Baccharis tricuneata var ., Bidens triplinervia var., Breutelia chryse.a, Halenia sp.(9771, 7505) and Cortaderia c f . sericantha. As a rule there are more herbaceous species and less bryophytic and lichen spec1 es than in the breutelietosum ; in addition , the average number of spe c i es i s ÂŁ lightly lower . Gentianella species are the most constant differential taxa. G. nevadensis is only known from the grass paramos N of Bogota and from the Venezuelan Si erra Nevada de Merida. G. corymbosa i s widely distributed in the Colombian and Ecuadorian paramos . The pres ence of Gentianella spp. (and also of other differenti al species), the high cover of the compact Plantago rigida cushions, and the absence of hygrophytic bryophytes and of lichens are characteristics of this subassociation. Rel. 505, and the rings of floating Plantago rigida cushions described from th e Paramo de Sumapaz (Cleef 1978) are provisionally ranked under the gentianelletosum. More data are needed, but these stands may represent a new syntaxon within the Hyperico- Plantaginetum rigidae.

144

The cushion bog of rel. 263 was not homogenous, as it included some elements from adjacent humid zonal and azonal vegetations. Synecology: This subassociation occurs in gently sloping (up to 8째) boggy valleys or on former lake-floors, most in the bunchgrass pararno. The substrate is generally peaty clay, 80 ern thick in soligenous stands to more than 120 ern above lake sediments. The pH in the rootzone is 5.1-6.4. The peaty clay (pH 5 . 4) of the soligenous bog (rel. 410) overlies a 20 ern thick compact sandy layer (pH 5.8) with root (or stern) fragments on red sandstone. The young compact Plantago rigida hummocks hardly permit establishment of seedlings. It may take years before the cushions begin to decay. Eryngium humile indicates frequent grazing cattle. Distribution: The gentianelletosum nevadensis was studied most intensively in the bunchgrass pararno on the dry side of the mountains between 3600 and 3900 rn, rnainly ' in the western part of the Colombian Cordillera Oriental.Up to nearly 4200 rn, stands were observed in the headwaters of Rio Lagunillas (Boquer6n de Chusque) in the Sierra Nevada del Cocuy. The subassociation is also present between 4050 and 4150 rn in the Sierra Nevada de Merida, Venezuela. 65b.

Subass. breutelietosum subass. nov. type: rel. 282; table 13; Fig. 57, 62, 63 (also Fig. 42, 70) photo: Cleef 1978, photo 168

Physiognomy: This subassociation comprises bamboo pararno cushion bogs with bryophytes (mosses become predominant) . Composition & syntaxonorny: Differential species are Chorisodontium speciosum (common), C. wallisii (rare), Herbertus subdentatus (large form), Rhacocarpus purpurascens, Cladia aggregata (with inflated podetia), Oropogon loxensis, Breutelia allionii, Anastrophyllum nigrescens, A. leucostomum, Geranium confertum, Werneria nu<.ilis ssp. angustifolia, and those reported under the variant with Valeriana plantaginea. The average number of species is higher than in the gentianelletosum. subassociation contains twice as many cryptogamic species as the

gentianelletosum. The breutelietosum is floristically well defined and differs from the gentianelletosum by numerous differential species. The lower cover of Plantago rigida and simultaneously the higher cover of bryophytes are diagnostic characteristics also. The average cover of Plantago rigida is about 65%. Synecology: Cushion bogs of the breutelietosum carry a number of hygrophytic taxa that are sustained by permanent humidity and fog. Most of these are bryophytes listed under "composition". They start to grow on the Plantago rigida cushions, or on the interstices, e . g. Breutelia allionii. This moss species may partly or completely cover the decayed Plantago rigida cushions, as observed in several locations between 3800 and 4000 m in the Paramo de Sumapaz. As a result of diminishing vitality the Plantago rigida cushions in the upper barnboo-pararno may die-off within about 10 years. The substrates are clayey peat or gyttja, and vary from shallow soligenous peat (rel. 275) to thick gyttja on former lake-floors (rel. 55, 111, 263A). The pH under the Plantago cushions is 5.1-5.5 (-6.2). Slopes are 5째-10째. Distribution: The subassociation has only been found on the humid side of the mountains in the bamboo paramos between 3600 and 4150 rn. Particularly well developed are the stands in the Paramo de Surnapaz. Locally this vegetation type reaches into the lower superpararno of the Nevado de Sumapaz e.g. with the variant of Valeriana plantciginea.

14S

6Sbb. variant of Valeriana plantaginea var. nov. type: rel. 27S; table 13 Physiognomy & syne co logy: Plantago rigida cushions in the high paramos with a cover of about SO%, are mainl y thriving on atmosperical humidity and to a less or degree on e daphi cal wa t e r. Bryophytes are consp icuous jus t as the large rosettes of Valeriana plantaginea, Senecio niveo-aureus and Lachemilla nivalis, which are about 30 em high and have a cover of less than 10%. Most of the associated vas cular species are geophytes. Soils on calcareous bedrock ar e thin and clayey or gravelly. Fros t heaving and successive solifluction are common at t hese heights . and strongly affect the vegetation. Composition & syntax onomy: Differential species are mainl y hygrophyt ic high paramo and superparamo taxa, most of them character i stic for the humid s ide of the Cordillera , e.g. Valeriana plantaginea. Plants of this spec i es belong to the s uperparamo populations and generally grow on outcrops and screes in the Colombian Cordillera Oriental. Other d{fferential species are Lycopodium crassum, Lysipomia sphagnophila ssp. minor (var. cocuyensis var. in ed.), Cetraria islandica var. pseudo- islandica, Thamnolia vermicularis, Senecio niveo- aureus , Draba sp. (1310 , white peta ls) , Draba s p. (1300 , yellow pe t a ls) , Ourisia muscosa, Plagiochila cuatrecasasii. In addition may be mentioned: Oropogon loxensis , Anastrophyllum spp., Lophocolea sp., Metzgeria sp., Siphula spp.,Riccardia sp., Anaplolejeunea conferta, Werneria humilis var. angustifoli~ and Azorella multifida, Didymodon laevigatus, Morinia

ehrenbergiana. The vegetation is to be considered as an upper condens a tion zone variant of the Hyperico-Plantaginetum rigidae breutelietosum. It is floristically well def ine d by a dozen differential species, mainly hygrophyt ic taxa from the high paramo, including the superparamo. Distribution: This variant is only known from the summit area of the Nevado de Sumapaz, 4100-41SO m. It cari, however, also be expe c ted on the Amazonian slope of the high Andes between 4100 and 4300 m, in the Colombi an Cordillera Central and in Ecuador. Note: The lichen Oropogon loxensis is also a common ba rk epiphy te of the timberline forest, in paramo thickets a nd dwarfforests . In the Paramo de Sumapaz this lichen species is common on top of Plantago rigida cu shions, and r e tains much water from fog. 66.

Oritrophio peruvianae- Oreoboletum obtusanguli ass. nov . type: rel. 147; table 13; Fig. 64 photo: Cleef 1978, photo 174-176; Photo 17S shows the t ype locality lit.: Cleef 1978, Godley 1978 , Oberdorfer 1960, Roivainen 19S4, Villagran M. 1980

Physiognomy: This association comprises cyperaceous paramo cushion bog. Mosses may cover more than half of the cushions, but a r e nearly absent on young hummocks. In wet stands on peat in lower areas, Sphagnum cuspidatum and algae are characteristi c in water-loaded depressions. Conspicuous rosettes of Oritrophium peruvianum up t o IS em may have a cover of 2S%.

146

Composition & syntaxonomy : Oreobolus obtusangulus forms the paramo Oreobolus cushion bogs reported earlier (Cleef 1978). It develops into compact hummocks . Oritrophium peruvianum is a selective character species , distributed in the paramos from Venezuela to northern Peru (Cuatrecasas 1969 and in litt.). The average number of species is 20 (9-36) in 12 releves. The Oritrophio-Oreboletum mainly differs by its two character species Oreobolus obtusangulus and Oritrophium peruvianum from the other associations of the Gentiano-Oritrophion . Character species of order and class are poorly represented and are nearly absent in the xyridetosum. The paramo Oreobolus cushion bogs (Oritrophio-Oreoboletum) are ranked under the Gentiano-Oritrophion. Alliance character species are scarce, but differential species are well represented. Ecologically the Oritrophio-Oreoboletum belongs undoubtedly to the paramo cushion bog alliance. In addition, Oreobolus obtusangulus was observed in succession with the Hyperico-Plantaginetum rigidae and with the Floscaldasio-Distichietum. Magellanic Oreobolus obtusangulus cushion bogs studied in southern Chile by Oberdorfer (1960) were placed in the Astelio~Oreobolion Oberd. (Myrteolo-Sohagnetea Oberd . ) . The paramo cushion bogs of the Oritrophio-Oreoboletum (Wernerietea) are altitudinally vicariant with the paramo Sphagnum bogs (with Myrteola oxycoccoides) in lower locations , which belong to a not yet described class. Synecology: Paramo cushion bogs in wet depressions, in moist valleys and also on small former lake-floors . Soligenous Oreobolus cushions frequently occur on the sides of small moist valleys containing Sphagnum bogs, cushion bogs (Gentiano~Oritrophion), flush-communities (Wernerion crassae-pygmaeae), dense Espeletia stands and grass mires (Calamagrostion ligulatae). They also occur on washed-out humid glacial sand at the basis of terminal moraines between grass paramo and superparamo (Cleef 1978; photo 174). The thickness and nature of the soils vary considerably. They are humic clayey to coarse sandy, and consist of clayey peat in valley bogs or of gyttja in filled-up lakes. The pH in the rootzone under soligenous cushions is 4 . 9-5 . I. The Oritrophio-Oreoboletum is oligotrafent to mesotrafent. The slopes are up to 7째, as an exception 15째 . Distribution : Phytosociological releves of the OritrophioOreoboletum have only been collected in the paramos of the Colombian Cor,dillera Oriental, where Oreobolus obtusangulus cushion bog occurs from the subparamo at 3150 m up into the lowermost superparamo, at 4400 m. The association has not been obeserved in other paramos , but herbarium vouchers (COL, US) indicate that compact rigid Oreobolus obtusangulus cushions must be present in the southern part of the Colombian Cordillera Central (Macizo Colombiano, Cumbal) and in Ecuadorian paramos. For the last areas this is supported by lists of collections and descriptions of sites of Ecuadorian paramo cushion bogs by 0llgaard & Balslev (1979) and 0llgaard (in litt.) . Note : The zonal lower paramos of the Colombian Cordillera Oriental also contain small, more lax tufts of Oreobolus obtusangulus, with conspicuous reddish sheets . These belong to the ssp. rubrovaginatus described by Koyama (1969) from the summit area of Serra Neblina (Brasil) .

147

66a.

Subass. typicum subass. nov. t ype : rel. 147; table 13; Fig. 64 photo: Cleef 1978, photo 174-176; photo 175 (bog Ln the background shows the type locality).

Physiognomy: Cyperaceous cushion bog dominated by low chamaephy t es; low rosette plants, rale dwarfshrub and mos ses may be present as well. Composition : Different against the xyridetosum are mostly the species that together are also differential for the alliance. They inc lude AZtensteinia paZudosa, BreuteZia spp. , CampyZopus cavifolius, Bartsia sp., Nertera granadensis, Pernettya prostrata, Sphagnum cuspidatum,Riccardia sp . and Cortaderia sericantha. The richness in species is similar as in the association. The releves available do not justify a subdivision as made for the HypericoPZantaginetum rigidae (viz. in a unit poor in species representing firm cushions, and a mossy cushion vegeta tion rich in species). Presence of the variant of Rhacocarpus purpurascens is determined by this mo ss species and/or Werneria humiZis var. angustifolia (var. ined.) Synecology :

See a ssociation .

Distribution: The subass. typicum is distributed throughout the Colombian Cordillera Ori ental and was studied from the lower grass paramo at 35 75 m up into the lower s up erparamo a t 4400 m. This vegetation type ex tends as far as the high paramos in the southern part of the Colombi an Cordillera Central and the Ecuadorian Cordillera Oriental. 66aa. Variant of Rhacocarpus purpurascens var . nov. type: rel. 152; table 13; Fig. 64 photo: Cleef 1978, photo 176 Physiognomy :路

Cyperaceous cushion bogs (see under association).

Composition & syntaxonomy: Differential species are the endemic cushion chamaephyte Werneria humiZis var. angustifolia (var. ine d . ) and the moss Rhacocarpus purpurascens, (both hygrophytic) . Wer neria humilis only grows in the southern paramos (Sumapaz, Cruz Verde, Palacio) of the Colombian Cordillera Ori ental but the species extends as far as the Ecuador ian p2.ramos. Rhacocarpus purpui>as cens has a (wide) tropical-high montane and subantactic distribution . The number of species varies from 10 to 36 in 4 releves depending on the age of the cyperaceous cushions. ~ ynecology: The variant occurs on small former lake-floors, on the edge of Sphagnum bog and on gently sloping peaty ground with Hgperico- Plantaginetum rigidae. The pH in the upper peat l ayer is 4 .8-4.9 reflecting rather oligotrophic conditions .

Distribution: The variant is only known from the southern bamboo paramos (3575-4000 m) of the Colombian Cordillera Oriental, but is exp ec t ed to extend to other humid grass paramos of the northern Andes .

148

66b.

Subass. xyridetosum subass. nov. type: rel . 134; table 13

Physiognomy: These are cyperaceous cushion bogs with a number of low herbaceous rosette species and dark green-blackish mosses . Composition & syntaxonomy: Differential species are CastrateZZa piZoseZZoides, Campylopus richardii and Rhynchospora paramorum, which are characteristic elements for zonal grass paramo vegetation; further also and Xyris acutifolia. The number of species is II and 23 in the two releves. Differential species and differences in habitat distinguish the two subassociations of the Oritrophio-Oreoboletum. The xyridetosum is intermediate between the Gentiano-~ritrophion and the Xyri s bog communities. Floristics and physiognomy, e.g. mainly the presence and the dominance of Oreobolus cushion bog, determine the present assignment to the Gentiano-Oritrophion.

Pinguicula elongata

Synecology: The vegetation forms small wet boggy patches in depressions in the zonal lower paramos. The peaty to clayey soils are rather acid (pH 4.8-5.0) in the top layer and have a gravelly base . The stands are found on slopes (30-15째). Distribution: This vegetation was only seen in the Paramo de Sumapaz and the Sierra Nevada del Cocuy between 3150 an 3630 m.

149

SPHAGNUM BOGS Sphagnum bogs are common in the l ower pa rt o f the paramo be lt and the upper pa rt of the Ande an forest belt . In the study area they a re loc ate d between 2800 and 3800 m on the humid a s we ll as on the dry side of the Cordill e ra (Fi g. 86 ) . Towards higher altitude s they are gradua lly replaced by cushion bogs , made up of va scular plants , e . g. the Hyperiao - Pl ant aginetum rigidae (63) , the Oritrophio - Oreoho l etum (66) and the Flosaaldasio - Dis tiahietum (63) , belonging to the Gentiano - Or itrophion (Or itrophio - WernerietaliaJ . Sphagnum bo gs are floristicall y distin ctly different f rom v a s cul ar cushion bogs , and they belong t o another class , treated in a forthcoming paper . Sphagnum magellanicum and S. sanato- josephense are most common cha r ac teri s tic species , that make up the paramo Sphagnum bogs . Othe r Sphagnum speci e s are S. auspidatum~ S. oxyphyllum~ S . suhseaundum~ S. recurvum, and S. aompaatum. Sphagnum cyclophyllum~ howeve r , i s common in the Oritrophio Wernerietalia . Characteristic bryophytes i n the Sphagnum bogs inc lude also Riaaardia spp ., Campylopus aucullatifolius~ Leptodontium wallis ii~ Breutelia spp ., Lepidozia spp . (e.g . L. aur iculata, L. maaroaole a~ L. wallisii )~ Kur zia vel'ruaosa, Adelanthus lindenhergianus ~ Anastr ophyllum l e uaost omum~ A. nigresaens, Leptosayphus cleefii and Cephalo zia dussii. Cladia aggr egata and spec ies of Cladonia subg . Cladina are common li chens . The taxonomy and ecology of rendeer moss e s i n the Colombian paramos was tre a ted by Sipman & Cleef (1979) , who r eport e d Cladonia holiviana (strain I) , C. aolomhiana (strain I) , C. aonfusa and C. polia a s t r ue Sphagnum bog species . Frequently a ssociat ed plant s, also common in zonal par amo communities , are Calamagrostis effusa~ SWallenoahloa tesselata~ Pernettya prostra ta~ Vaccinium florihundum v ar . r amosissimum 3

Rhynahospora aautifolia~

macrochaeta~ Hypericum lanaioides~ Oreoholus ohtusangulus ~ Xyris pinchinahens is~ Bleahnum loxense and Halenia spp . Rare are ruiziana~ Hyper icum graciliforme and Xyris suhulata. Pernettya

Carex

Rhynahospor a prostrata is pre sent with var . purpurea; Festuaa c f. dolichophylla tusso cks are less fr equentl y a ssociated species . Bleahum loxense is a characteristi c dwarf treefern and is one of the highest lo c ated spe c ies of the austral-antarctic section Lomaria This fern species is common on peaty soil in the lower boggy paramos (3000-3700 m) from southern Ecuador t o Ven e zuela and Costa Rica . Par amo Sphagnum bogs are general l y about I to 4 m thick . The upper peatl ayer is moder a t e ly acid (pH 4 . 6-5.3 ) . A hummock- hollow relief de s c ribed from other cool and temperate Sphagnum bogs is reported here for all types o f bogs . Lozano & Schne tter (1976 , Fig . 2) illustrated this for Puya goudotiana - Sphagnum bogs at 3400 m i n the Paramo de Cruz Verde ne ar Bogota . Some other examples are p r esented in this study. All chara cter i sti c spe cies are not a lways pre s ent in each phytocoenosis but from we t hollow to dry hummock the following species are respectivel y represented: Sphagnum auspidatum~ S. sancto- josephense and S. magellanicum . The last spe cies also t ake s the s ame hummock position in the European Oxycocco - Sphagnetea Br . Bl . et R.Tx. 1943 and the magellanic Myr teolo - Sphagnetea Oberd . 1960 . In paramo Sphagnum bogs the presence or absence of SWallenochloa bamboo clumps is decisive for the type of hollow-hummock sequenc e . A number of typically SWallenochloa-associated bryophyte species det e rmine the composition and shape of the hummocks in the bamboo-Sphagnum bogs (Fig . 67) . Swallenochloa c lumps are freq uently associ a t ed with Sphagnum magellaniaum, or in drier places with Breute lia chrysea . Lepidozi a aur iculata and/ or Leptodontium wallisii are chara cteristic for well-developed bamboo hummocks , toge ther with Chorisodontium spp . and Sphaerophorus melanocarpus. Other hummock taxa are Campy lopus p ittieri~ Atractylocarpus longisetus ~ grasses (Calamagrostis effusa~ C. planifolia, Festuaa cf . dolichophyllai~ Dister igma empetrifolium, Vaccinium florihundum var . ramosissimum and species of Cladonia subg . Cenomyce. In the hollows occur

ISO

Sphagnum cuspidatum, S. recurvum, S. sancto- josephense, Riccardia spp. (e . g . 9396 ) , Carex pichinchensis, AnastrophyZZum nigrescens, I soetes boyacensis, CZadonia coZombiana, etc . Intermediate between hummock and hollow (at the edge of the hummocks) , e.g. BreuteZia s p., Carex bonpZandii, Xyris acutifolia, GZossodium aversum, BZechnum Zoxense , GongyZanthus innovans and Sphagnum oxyphyZZum are found. About the succession in paramo Sphagnum bogs relatively little is known at pre s ent. In addition to pollendiagrams in a number of studies interpreted by Vander Hammen and coworker.s, only Weber (1958) and Lozano & Schnetter (1976) deal with this subject . Weber (l.c . ) reported from old, relatively dry hummocks of Sphagnum in Costa Rican paramo bogs Gentiana sedifolia, EZaphogZossum Zatifolium Sw., ArcytophyZZum Zavarum Schum. and Rubus cf. eriocarpus Liebm. Lozano & Schnetter (l.c.) described and illustrated four different stage s, from Puya goudotiana - Sphagnum bog to a climax thicket with DipZostephium r evoZutum, from the Paramo de Cruz Verde at 3400 m near Bogota. This sequence is as f Gllows . A huge Sphagnum mageZZanicum hummock is first colonized by CaZamagr ostis ~ffusa, Carex bonpZandii, VaZer iana Zongifolia and ft~rteoZa oxycoccoides . In the meantime most Sphagnum mageZZanicum dies off, while Myr teoZa oxycoccoides covers the hummock. Next, a dwarfshrub of Aragoa abietina, Eupatorium (Ager atina ) gynoxoide s and DipZostephium phy Zi coides appears with Ger anium multiceps in the herbaceous understore y. Another stage (which might be succe ssional to .the previous one ) is the development of DipZostephium revoZutum shrub on old dead Sphagnum mageZZanicum hummocks with the bamboo Au Zonemia t rianae and Senecio gar cia- barrigae . The hollows contain, according to Lozano & Schnetter (l.c.), Sphagnum capiZZaceum , which probably might be identical with S. sancto- josephense or S. cuspidatum, which are frequent species of hollows in the bog vegetation of this paramo. BZechnum Zoxense was mostly found on young low reddish hummocks of

Sphagnum mageZZanicum. In addition to DipZos tephium revoZutum climax bush (71) other shrub communities are found on Sphagnum bogs: e.g. the Aragoetum abietinae (72) and, locally, Senecio fZos - fragran s or Baccharis revoZuta shrub. Also dense Espe Zetia stands are frequently found and they are dominated by one of the following geographically vicariant species: EspeZetia grandi f Zora, E. miradorensis, E. chocontana, E. arbaZaezii, E. muri ZZoi, E. i ncana, E. nemenkenii, E. Zopezii and E. rosi tae var.

monocephaZa . The Aragoetum abietinaa develops in Xyris acutifoZia - Sphagnum bogs in the paramos between Neusa and S. Cayetano (Cundinamarca). There, at 3660 m, decaying

Sphagnum mageZZanicum appeared to be overgrown by Riacar dia sp. (6226a) and CephaZozieZZa cf. f ragiZZima (6226) and to a lesser ex tent by Lepidozia sp. (6223). In a next stage, prostrate dwarfshrub of Vaccinium fZoribundum var . ramosissimum becomes settled and together with Riccar dia it may have a cover of about 50 %. The died off small trunks of BZechnum Zoxense are covered with CZadonia andesita and C. hypoxantoides. The succession terminates with the appearance of Ar agoa abietina dwarfshrub containing PZeuroz ium schr eberi , Hypnum amabiZe, Bryum biZZardier i , and Ger anium sibbaZdi oides . Apparently these Sphagnum bogs are mainly of two ages. Radiocarbon dating of several of them indicated about 2800-3000 yrs B.P. and about 5000 yrs B.P. for the various samples. These ages are corroborated by a number of pollendiagrams for the Paramo de Palacio (Vander Hammen & Gonzalez 1960), the Cienaga del Visitador, Paramo de Guantiva (Vander Hammen & Gonzalez 1965), the Sierra Nevada del Cocuy (Gonzalez et al. 1965, Vander Hammen et al. 1981) and the Laguna Gobernador, Paramo de Sumapaz (G.B.A. van Reenen, in prep.). In lower bamboo paramos the Sphagnum bog is also distributed on the hillsides, where they give way to slope bogs (Fig. 79). The gradual transition to zonal slope vegetation (e.g. comm. 10: community of SwaZZenochZoa with Sphagnum and/or Br euteZia ) is basically not much different from the Sphagnum bogs. All paramo Sphagnum bog communities in the study area will be treated in

lSI

a syntaxonomic study to be published in future. With the exception of shrubby climax vegetation, four main types of Sphagnum bogs (67-70) can be distinguished in the paramos of the Colombian Cordillera Oriental. Sphagnum spp. have an average cover of about 50% in the following communities, except in the first one. 67. Sphagnum bog with EspeZetia and BZechnum Zoxense 68. Sphagnum bog with SWaZZenochZoa 69. Sphagnum bog with giant Puya 70. Xyris-Sphagnum bog. The Aragoetum abietinae and (part of the) DipZostephietum revoZuti are shrubby climax communities, which may develop on Sphagnum bogs in the study area . They will be treated presently together with other azonal pararno shrub-communities. 67. Sphagnum bog with EspeZetia and BZechnum Zoxense Fig. 65; photo : Van der Hammen 1973 , Fig. 2. Small patches on gently sloping (1-5掳) wet valley floors in the upper Andean forest or shrubparamb carrying a dense, low (tree} fern brake with sternrosettes of EspeZetia. BZechnum Zoxense grows in dense clumps up to 100 ern high and with a cover of 50-75 %. EspeZetia kiZZipii var . kiZZipii and E. nemenkenii are common geographically vicariant species in this kind of habitat. Large eriocaulaceous rosettes are common also e.g. PaepaZanthus cf. crassicauZis and P. alpinus. Dwarfshrub of Baccharis revoZuta~ Hypericum graciliformis and SWaZZenochZoa clumps may cover most of the fieldlayer. The Sphagnum cover is much lower than in other types of 路路 Sphagnum bog, due to shade. The bl ack peaty to clayey soils are thick and waterlogged. The upper laye r is moderately acid (pH 4.9-5.5). The Aoo-layer is well deve loped (up to 5 ern thick) and consists mainly of litter of Cyperaceae, Grarnine ae and BZechnum Zoxense . This bog type is becoming very rare, as a result of agricultural activities following drainage through ditches. The endemic EspeZetia nemenkenii and E. kiZZipii var. kiZZipii must be considered as endangered species. 68. Sphagnum bog with SwaZZenochZoa Fig. 66 & 67; photo : Gradstein e t al. 1977 , plate ID. Dense bamboo - Sphagnum bogs are present in the upper part of the Andean cloud forest belt and go up to 3600 rn in the lower grass pararno. The depres s ions fill e d with peat bog are rather deep and characterized by SWaZZenochZoa tesseZata and various species of Sphagnum , e ach of which with a cover of 30-90%. Also present are BreuteZia spp. (cover up to IS %) and CampyZopus cucuZZatifoZius (cover up to 5%). The cover of species of EspeZetia is usua lly low. Some taxa of other Sphagnum bogs are absent, e.g. species of Rhynchospora~ Hypericum~ Xyris~ CZadonia subg. CZadina~ Or eoboZus obtusanguZus and BZechnum Zoxense. The bogs, which were studied between the Sumapaz and the Cocuy, are mostl y large and level, and are mainly located on the outer wet slopes of the Cordillera, on which bamboo paramos are found. The upp er part of the wet peat layer is moderately to weakly acid (pH 5.1-6. I). 69. Sphagnum bog with giant Puya This kind of Sphagnum bog is eas ily recogni zed by the giant ros e tt es of Puya goudotiana or locally P. aristiguietae with large columnar inflores cences of about 3-5 m. The diameter of these prickly rosettes is 1-2 m and their height is up to 1-1.5 m. After flowe ring the rosettes die off but it takes a long time before they decay to litter (Fig. 68). The large rosettes provide shelter to frogs, e.g. HyZa. Small Anurae are common in pararno Sphagnum bogs and in the

152 boggy bamboo vegetation, but scarce to absent in vascular cushionbogs in higher areas. Puya goudotiana , according to Smith & Downs (1974), is widely distributed in the humid lower paramos of the Colombian Cordillera Oriental between 2800 and 3500 m. Puya aristeguietae is described from Venezuelan paramos, but is now known to extend into Colombia, where its south-western limit was found on the dry side of the Sierra Nevada del Cocuy between 3500 and 3770 m. Puya hamata L.B. Smith, is the giant species characteristic in Sphagnum bogs in the paramos of southern Columbia and northern Ecuador. Geranium multiceps of G. subnudicaule with their characteristic leathery, microphyllous, crenate leaves are associated species but they are virtually absent in other Sphagnum bogs. Geographically vicariant species of Espeletia with stemrosettes , e.g. Espeletia l opezii, E. oswaldiana (forma), E. muriUoi (? lev . 393) and E. grandiflora may be associated. Other common and characteristic species are Rhynchospora macrochaeta, Hypericum lancioides 3 Oreobolus obtusangulus, Campylopus cucullatifolius, Breutelia spp., Blechnum loxense, Carex pichinchensis, Arcytophyllum muticum, Vaccinium flo ribundum var. ramosissimum, Pernettya prostrata, Cladonia boliviana and Disterigma empetrifolium . Species of Xyris and Halenia are not common. This type of bog is common in the bamboo paramos between 2800 and 3770 m, where it covers wet valley floors, but also occurs on the gentle slopes of the surrounding hill-sides (up to 5째(-10째)). The soil is a black clayey peat, in most places thicker than 120 em. The top layer of the peat is strongly to moderately acid (pH 4.2-5.2 (5.7)). 69a. Sphagnum bog with SWallenochloa and Puya goudotiana Fig. 68 (also Fig . 69) photos: Cuatrecasas 1934, Lam. 32, fig. I; Cuatrecasas 1958, plate 17; Lozano & Schnetter 1976, fig. I & 2 .

Sphagnum bog with Puya goudotiana are common in the lower bamboo paramos and in the upper Andean cloud forest in the Colombian Cordillera Oriental . In addition to the species mentioned above for giant Puya sphagnum bogs , these bogs contain the folJQwing species : Swallenochloa tesselata, Senecio subruncinnatus, Bartsia sp . , Breutelia allionii, Campylopus cucullati f olius, Lepidozia sp., Kurzia verrucosa, Cladonia andesita, Lycopodium cruentum and Cladonia boliviana. Sp ec ies of Halenia are absent. Pseudocephalozia quadrifolia (rel . 61), Sphagnum requrvum (rel. 365) and s. subsecundum (rel. 393) have been found associated in one place. The Sphagnum species have a cover of more than SO%. Juvenile Diplostephium revolutum shrub is common in this type of bog and is considered by Lozano & Schnetter (1976) as successional to the climax with Diplostephium revolutum dwarfforest. Our data suggest a succession to the Diplostephium revoluti (70) from Puya goudotiana - Sphagnum bog as well as one from the Hyperico - Plantaginetum r igidae (65) and the Caricetum pichinchensis (49) to the Diplostephietum revoluti. Puya goudotiana - Sphagnum bog is found throughout the humid lower paramos of the Colombian Cordillera Oriental between 2800 and 3500 (3680) m. Note: In the paramos near Bogota (Cruz Verde, Chisaca) low Senecio flos-fragrans shrub was locally notices associated with Pleurozium schreberi, Hypnum amabile and Myrteola oxycoccoides in Sphagnum bog (3500-3700 m) . Mossy hummocks in the Paramo de Cruz Verde may vary from 40 to 70 em in height. 69b . Sphagnum bog with Puya aristiguietae

Puya aristiguietae is a geographically vicariant Puya species in Venezuelan subparamo bogs of the Sierra Nevada de Merida. On the dry side of the Sierra

!53 Nevada del Cocuy this giant rosette species replaces Puya goudotiana in Sphagnum bogs between 3550 and 3770 m (Paramo Concavo), and is associated with EspeZetia Zopezii, Xyris subuZata, Geranium subnudicauZe, Carex bonpZandii, Oritrophium peruvianum and Juncus echinocephaZus. Sphagnum oxyphyZZum seems the main hummock species and S. sancto-josephense is characteristic for the hollows. 70. Xyris-Sphagnum bog Paramo bogs with Xyris acutifoZia are common , mainly between 3300 and 3700 m in the upper subparamo and lower grass paramo of the Colombian Cordillera Oriental. Xyris acutifoZia is the most characteristic species in the paramos from Chachapoyas (N. Peru) to Venezuela between (2200) 2900 and 3750 m. In the study area Xyris subuZata may locally replace Xyris acutifoZia. Common characteristic species are Hypericum Zancioides and other Hypericum species, BZechnum Zoxense, HaZenia spp. and Kurzia sp . SWaZZenochZoa tesseZata and ArcytophyZZum muticum are absent in Xyris - Sphagnum bogs. The top layer of the clayey to peaty black soils is moderately ac id (pH 4.6 5.3). The Xyris paramo bogs apparently represent a clearly distinct syntaxon , which will be defined in the future. According to Weber (1958) , Sphagnum - Xyris peatbog of a similar nature is found also in the Costa Rican paramos. 70a . EspeZetia - Xyris - Sphagnum bog In contrast to Xyris acutifoZia - Sphagnum bog (70b), the average cover of Xyris is rather low in this bog reaching not more than 25%. EspeZetia spp . are trequent and may have a cover of about 50%. Other common species are BreuteZia, Lepidozia and CZadonia subg. CZadina (Sipman & Cleef 1979), and also Pernettya prostrata and CZadia aggregata. The black upper layer of the water-logged peat is moderately acid (pH 4.6 4.8). A more impermeable layer underl ying the upper layer may be the cause of the present Sphagnum bog. EspeZetia - Xyris - Sphagnum bogs are common in the study area between 3300 and 3700 m. On the basis of mainly floristical properties these bogs can be subdivided into bogs with either CampyZopus cucuZZatifoZius or OreoboZus

obtusanguZus.

70aa. EspeZetia - Xyris - Sphagnum bog with CampyZopus cucuZZatifoZius Fig . 78 These Sphagnum bogs are presently only known from the dry lower bunchgrass paramos North of Bogota (Neusa, San Cayetano) between 3600 and 3700 m. It is developed as large ombrotrophic peat bog near the Laguna Verde and in small Sphagnum-filled valleys. Xyris acutifoZia has a cover of 20%. CampyZopus cucuiZatifoZius generally has a low cover. EspeZetia chocontana, CampyZopus pittieri, Aragoa abietina dwarfshrub, Rhacocarpus purpurascens and Vaccinium fZoribundum var. ramosissimum are frequently associated, and have a low cover. Rosettes of Puya santosii and P. trianae are present in all releves with an average cover of about. 10%. This vegetation type apparently may lead to the rare Aragoetum abietinae, the climax vegetation in the paramo bogs near Bogota (see 72).

IS4 70 ab. Espeletia - Xyris - Sphagnum bog with Or eobolus obtusangulus photo: Van der Hammen 1962 , Fig. I This communi t y is common in the study area between 3300 and 3600 m, generally on former filled -up lakes and in small valleys. The presence of Oreobolus obtusangulus against the absence of Campylopus cucullatifoiius and Aragoa abietina is the main floristic difference with the previous community. The average cover of Puya species is about 1%, of Xyris species about 10%. Stemrosettes of Espeletia may be denser than in the previous community (average cover 15 %; 0- 55%). The principal geographically vicar iant species are Espeletia grandiflora, E. arbelaeziana, E. incana and E. murilloi. Hypericum species may be present, e.g. H. laricifolium ssp. laricoides , H. lancioides, H. strictum and H. graciliforme. Low shrub of Diplostephium revolutum may also be present and indicates tha t this community is successional to the Diplostephietumrevoluti (79) a lso. The black peaty, clayey soi ls are about 2 m thick , wi th an underlying pa le ye llow or light brownish to gray clayey sand . 70b . Xyris acutifolia bog Fig. 38, 69 Charac teristic for this bog type a re small tufts of yellowis h-orange flowering Xyris acutifolia, with a cover of 10- 80% (average 50%), accompanied by Rhacocarpus purpurascens, Halenia sp(p.), Riccardia spp. , Blechnum loxense and tuft s of Calamagrostis effusa and Cortaderia sericantha. Scar ce or absent a r e SWallenochloa tesselata, Cladia aggragata, Pernettya prostrata var. purpurea), Campylopus cucullatifolius and Lepidozia. The average number of species is 22 (12 - 35) in 8 releves. Most of the stands consist of a well-d eveloped field layer and several rosette plants. Hypericum lancioides dwarfshrub has a low cover. The substrate is peaty clay of more than 120 em deep. The pH in the upper so il layer is S.O (4 .8*)-S.S. Slopes a r e up to IS 0 â&#x20AC;˘ The studied pure Xyris bogs occupy r e latively small areas in the southern paramos of the Colombian Cordillera Oriental, e.g. Paramo de Palacio, Cruz Verde, Chisaca and between Neusa and S. Cayetano. They occur from the subparamo at 33SO m up into the lower grass paramo at 3700 m.

Xyris acutifoZia bog vegetations can be subdivided into: I) moderate ly sloping (12 - 15Â°) soli genous bogs, which are present as small patches in zonal paramo vegetation. Floristic affinities with the zonal grass paramo is constituted here by e.g. Rhynchospora macrochaeta, Castratella piZoselloides and CampyZopus richardii . Characteristic are Myrteola oxycoccoides and a few solitary cushions of OreoboZus obtusangulus. Sphagnum species are absent. This type has a strong affinity to the Oritrophio Oreoboletum xyridetosum (66b) . 2) the gently sloping (3 - so) Xyris acutifolia - Sphagnum bog areas contain Aragoa abietina, slender reddish clubmosses (Lycopodium cruentum complex) and Kurzia verrucosa as accompanying characteristic species. Sphagnum cuspidatum, S. sancto- josephense or S. mageZZanicum may be dominant . Isoetes boyacensis may be immersed in the wet Sphagnum cuspidatum layer in bamboo paramo bogs (e. g. Paramo de Pal ac io). Espeletia chocontana and Vaccinium floribundum var . ramosissimum are characteristic for stands in bunchgrass paramo bogs (e.g. paramos NW of Neusa). Other Sphagnum communities Wet patches of Sphagnum bog hollows contain e.g. S. cuspidatum (Fig. 46)

155 and/or S. sancto-josephense and are locally distributed along peaty lake shores and in boggy glacial valleys between 3600 and 3850 m in the southern paramos of the study area. One of these Sphagnum species may be dominant and may be associated with sedges. In such a peaty hydrosere with small sedges (occasionally with Carex bonplandii ), other associated species are Lysipomia sphagnophila ssp . minor (large flowers), Bartsia sp. and Werneria humilis var. angustifolia . Species of Lepidozia, Breutelia and Riccardia are common but with a low cover. Carex pichinchensis (cover 70-80%) is also a common associate. The ecological difference with the Caricetum pichinchensis (49) is the absence of mineral soil. The Sphagnum turf is slightly acid (pH 4.7-5.2). It cannot be ruled out that the original sedge marsh of the Caricetum pichinchensis prece~~ed the Sph~gnum ~og in the past. Stands were observed between 3650 and 3850 m ~n the southern paramus. An interesting aquatic growth of Sphagnum was earlier described from the Andabobos watershed at 3700-3750 min the Paramo de Sumapaz (Cleef 1978), where a Sphagnum cuspidatum layer floats in open water of deep glacial lakes, which are also covered with floating cushions of Plantago rigida. The 15-25 em thick Sphagnum auspidatum layer supports different herbaceous species, e.g. Callitriche sp., Elatine chilensis, Tillaea paludosa, Juncus cf. ecuadoriensis , Ranunculus limoselloides and even tufts of Calamagrostis coarctata and rosettes of Oritrophium limnophilum ssp. mutisianum (Cleef 1978, photo 170). Zonation from open water 'in the central .part of the lake towards the shore is as follows: I) Initially Plantago rigida rings float on open water while the Sphagnum cuspidatum carpet just starts to develop. Submerged masses of Sphagnum cyclophyllum and Drepanocladus revolvens may cover the interstices between the Plantago cushions, and several other character species of the Oritrophio- Wernerietalia, e.g. Werneria pygmaea, Oritrophium limnophilum ssp. mutisianum and Calamagrostis coarctata, are associated. 2) Next, the Sphagnum cuspidatum mat becomes predominant. Callitriche sp. and such amphibious species as Elatine chilensis and Tillaea paludosa become settled. 3) Towards the marshy shore, where the Sphagnum cuspidatum layer reaches the bottom, 1-2 m broad, lagg-like zone dominated by Ranunculus limnoselloides may fringe the lake. The pH of the water (4.5-4.9) in the Sphagnum auspidatum layer indicates slightly acid conditions. When the Plantago rigida cushions grow close together the lake's surface becomes filled up. Cushionbog of the Hyperico-Plantaginetum rigidae (65) then contains wet hollow-communities of the variant of Drepanocladus revolvens (62ad) of the Oritrophio- Wernerietum pygmaeae. The described Sphagnum cuspidatum vegetation represents a truely neotropical vicariant community, which is closely related to other temperate communities with S. cuspidatum. SHRUBS & DWARFFORESTS The azonal shrub formations in the paramo belt of the Colombian Cordillera Oriental are generally dominated by one single species, which mainly belongs either to the Compositae (Senecio , Diplostephiuml or to the Hypericaceae (Hypericum sect. Brathys ) . Species of Ericaceae and Melastomataceae are largely present or dominating in zonal forest line formations. They are only companion& in the azonal shrubs and dwarfforests. Compositae, mainly species of Gynoxys and Diplostephium are also dominant in the canopies of dwarfforests of the paramo belt; though also rosaceous (mainly Polylepis) dwarfforests are common. With regard to the woody genera mentioned above, some noteworthy aspects of their evolution and speciation in the paramos are given below, except for Polylepis, which is recently discussed by Simpson (1979).

156 The Compositae are undoubtedly the main constituents of azonal thickets and dwarfforests in the study area. Senecio (Senecioneae) and DipZostephium (Astereae) are predominant in thickets; species of Gynoxys (Senecioneae) represent different types of dwarfforest in the paramo belt. A comprehensive systematic survey of tropical Andean Senecioneae is not yet available, and only preliminary notes are presented on evolution and distribution of the above three genera. Cuatrecasas (1969) treated DipZostephium for Colombia. He mentioned its austral-antarctic affinities . The mbst primitive features are the enrolled leaves in the species of the series DenticuZata Cuatr, which are micro- to mesophyllous trees in the upper Andean forest. The most advanced members of DipZostephium are leptophyllous or nanophyllous dwarfshrub species of the high paramo. In the study area they are represented by DipZostephium coZombianum and D. gZutinosum (ser. LavanduZifoZia Cuatr.) , and D. rupestre (ser. Rupestria Cuatr.). The other DipZostephium species from intermediate altitudes in the study area belong to f he ser. SchuZtziana Cuatr. (D. juajibioyi, D. aZveoZatum, D. rhomboidaZe) and the ser. RosmarinifoZia Cuatr. (e.g . D. heterophyZZa, ~ D. Zacunosa, D. revoZutum). In spite of the numerious new DipZostephium spe cies described from the Peruvian and Ecuadorian Andes, the Colombian Andes with 80 (-100) species must be considered as the recent centre of DipZos tephium. Carlquist (1974) described the "insular woodiness" , i.e. originally herbaceous taxa that develop secundary xylem in isolated (sub)tropical habitats, as prevailing on oceanic islands and in summit areas on high mountains. He assumed that the temperate herbaceous taxa are more suited to develop woodiness than the tropical ones. This applies e.g â&#x20AC;˘ .to Senecioneae including Gynoxys (Carlquist , 1974) and also to Paragynoxys, by the present author regarded as one of the possible precursors of tropical woody Senecio. According to Cuatrecasas (1951) the woody species of Senecio dominating the azonal paramo shrub belong to four sections of the genus: I) Sect . LedifoZium Cuatr . : e.g. Senecio ZedifoZius and S. cacaosensis in dry resp. wet habitat. 2) Sect. Vaccinioides Cuatr .: e.g. Senecio vaccinioides, S. puZcheZZus, S. guantivanus , S. pungens and S. fZos-fragrans in dry to wet habitats . 3) Sect . Granata Cuatr.: e.g . Senecio nitidus, S. vernicosus, S. andicoZa and S. reissianus in dry to humid (wet) habitats . 4) Sect. RefZexus Cuatr.: e.g. S. guicanensis in dry to slightly humid zonal habitats. This section also contains other endemic superparamo species, e.g. S. geZidus (Parque Los Nevados). Other examples of paramo species demonstrating "insular woodiness" are

Niphogeton fruticosa (Umbelliferae), the rosaceous LachemiZZa poZyZepis, which belongs to the monotypic section PoZyZepides (Perry) Rothm. of LachemiZZa, and sp e cies of VaZeriana sect . Porteria Killip. From the latter some endemic species are present in the study area: e.g. VaZeriana triphyZZa and VaZeriana arborea, but not in well-developed thickets as in adjacent paramos . The woodiness of Hypericum, however , must be explained otherwise. The very ancestors of the neotropical section Brathys (Mutis ex L . f.) Choisy of Hypericum are closely related to woody species of the most primitive section CampyZosporus (Spach) R. Keller of tropical Africa (Robson 1977), which today are found in similar habitats as the tropical Andean species of Hypericum on the high equatorial African mountains. According to Robson (1977, fig . 4) the most primitive species of the section Brathys are presently found in the northern Andes of Colombia and Venezuela , Roraima (I species) , adjacent Central America and Cuba. The paramos ofÂˇ the study area probably contain most of the species of this section in the northern Andes and may thus be considered as its major South American centre.

157 SHRUBBY COMMUNITIES 71. Diplostephietum revoluti ass. nov. type: rel. 27; table 14; Fig. 70 (also Fig. 14 , 50, 51) lit .: Lozano & Schnetter 1976 photo: Cleef 1978, photo 163 (the Diplostephium revolutum stand represents rel. 116); Cuatrecasas 1954, plate 19. Physiognomy : This nano- to microphyllous dark greenish shrub is best characterized by its conspicuous spherical umbrella-like canopies. The general structure of the stands is as follows : I) shrub layer , I - 3m high, mainly of dark greenish spherical canopies of DipZostephium revolutum, with a cover of 60 - 90%. The up to 2 m high bamboos have a cover of 10 - 45 % and are part of the shrublayer; 2) an open herb and dwarfshrub layer , with a cover of about 30%; and 3) a conspicuous bryophyte layer , I - 5 (25 em) thick, with some low herbs . Lichens are scarce. Composition & syntaxonomy: The shrub Diplostephium revolutum is dominant; this endemic composite species is common in the paramos of the Colombian Cordillera Oriental (3200 - 4200 m) and less common in the Tolima - Ruiz massif in the Colombian Cordillera Central (Quatrecasas 1969 , Cleef et al., in press). Other frequent or conspicuous species are SwaZZenochZoa tesselata, BZechnum

Zoxense, Carex pichinchensis, Relbunium hypocarpium, Ophioglossum crotalophoroides, Pernettya prostrata (especially var. eZZiptica), Geranium sibbaldioides, ArcytophyZZum muticum, Adelanthus Zindenbergianus, Leptoscyphus cleefii, Bazzania robusta, SyzygieZZa Ziberata, and species of Hypericum, Plagiochila, Sphagnum, Riccardia and Lepidozia; Sphagnum spp, and Hypnum amabile have high cover values . Epiphytic cryptogams are abundant in the Diplostephietum revoluti. The most common are -Usnea spp . (1694, 3057), FruZZania tetraptera, FruZZania spp. (1697a, 4519), Brachiolejeunea Zaxifolia, Sphaerophorus melanocarpus, Everniastrum spp. (e.g . E. cirrhatum, E. catawbiense), Oropogon Zoxensis, Zygodon goudotii, Zygodon reinwardtii, Metzgeria spp. (e.g. 943, 1072, 4517) and Lejeuneaceae (e.g. 1697b , 1700 , 4518) . Pleurocarpous mosses (4523 , 4524) and Lophocolea fragmentissima have also been collected. The average number of (terrestric) species is 42 (21-62 in 8 releves). DipZostephium revolutum is the only (excl.) character species; this eliminates confusion with other related bog communities , e.g. the Aragoetum abietinae (72), the Senecionetum andicolae (73) and the Diplostephium aZveoZatum community (88). Bamboos are mostly present in the Diplostephietum revoZuti in the study area, but they are absent in the nearby Cordillera Central. Most stands show a strong relationship to paramo Sphagnum bogs, as indicated by a number of characteristic species (see "bog taxa", table 14). The "asociaci6n de Diplostephium revolutum" of Lozano & Schnetter (1976) represents rather a distinct subparamo syntaxon, which together with rel. 65 (present study) may be assigned to the subassociation level . Differential species include e.g. Paepalanthus colombiensis (?) or P. alpinus (det . Dr. R.N . Moldenke), Aragoa abietina (low cover), Aulonemia trianae and Geranium multiceps. Synecology: Thickets or dwarffores t with Diplostephium revolutum are common on boggy, waterlogged ground in grassparamos, e.g. in moist valleys and depressions , along lake-shor es and filled-up former lakes. The association is most common in the bamboo paramos. The Diplostephietum revoluti is a climax association that marks the end of the succession in several azonal boggy paramo communities. Howeve r, not each bog succession leads to the DipZostephietum revoluti; some may lead to other shrubby climax communities, e.g. Senecionetum reissiani (48), the Senecionetum andicolae (73), Diplostephium alveolatum shrub (88), the Aragoetum abietinae (72).

!58 Succession to the DipZostephie t um r evoZuti was observed in the Car icetum piahinahensi s (49), Carex j ame sonii community (52), Sphagnum sanato-josephense Ca Zamagrostis ZiguZata community (57), the Hyperiao - PZantagine tum rigi dae (65), and further in the giant Puya - Sphagnum bog (69) , EspeZetia - Xyr is - Sphagnum bog with Or eoboZus obtusanguZus (7oab) and in dense Sphagnum - BreuteZia SwaZZenoahZoa vegetation (10). Floristic elements of these communities are common in the understorey of th e DipZostephietum revoZuti . In the high paramos (3800 3900 m) of the Sumapaz, DipZos tephium revoZutum shrub was also noticed on a thick homogeneous mat of Breute Zia ahrysea and B. aZZionii. Sphagnum ayaZophy ZZum, rather a s pecies of the Oritr ophio - Werner ie t aZia, may be associated also. Apparently the DipZostephietum revoZuti in this case is developed on f ormer Hyperiao - PZantaginetum rigidae breuteZietosum. Common is DipZostephium aZveoZatum shrub (88), which takes over the rol e of DipZostephietum revoZuti in the highest located bogs on the crests of the Paramo de Sumapaz. Bamboos and species of Sphagnum are important with a cover of resp. about 40% and 65%. The presence of Sphaerophorus meZanoaarpus and of a number of hygrophyti c liverworts r e flect a rather steady and high atmospheric humidity. Epiphytic spe cies are also common on dense SwaZZenoahZoa clumps and on other organic matt er. The peaty soils are thi cker than 120 em and consist of brownish to gray ish c layey peat or gyttja with numerous roots. The uppe r part is moderately to weakly acid (pH 4.9-6.4). Schnetter et al. (1976) measured the pH in the upper soil lay er for one year, but they did not find a correl a tion with climatic fluctuations. Biological activity in the upper soil layer is extremely low Schnetter & Ca rdozo (1976), as may be expected in waterlogged bogs. The stands are found in level or slightly sloping areas (1- 5Â°). Observed were foraging activities by SyZviZagus and Cavia . Ca ttle uses dwarfforests for shelter. The use for fuel endangers this paramo bush . Distribution: The DipZostephietum revoZuti is common in the paramos of the Colombian Cordillera Oriental on both sides of the mountains, between 3300 and almost 4000 m. Stands in higher locations can be expected on the west slope of the Sierra Nevada del Cocuy (Cuatrecasas 1969) . The association was also reported as scarce from the Colombian Cordillera Central in the Tolima - Ruiz massif betwe en 3800 and 3900 m (Cuatracasas 1969, Cleef et al . , in press). 72. Aragoetum abieti nae ass. nov. type: rel. 197; table 14; Fig . 71 & 78 Physiognomy: The dark greenish nano- to leptophyllous conifer-like shrubs are dotted with white flowers. Closed stands are structured in: 1) a shrublayer, 1 - 2m high. Bamboos, if present, reach up to the canopy stratum. 2) a herbaceous - dwarfshrub layer up to 40 em hi gh; covering 1 to 15 %. 3) a groundlayer mainly made up of Sphagnum, usually together with pleurocarpous mosses. The mosslayer covers 80 to nearly 100%, but in dense stands only IS to 25%. Composition & syntaxonomy: Aragoa abietina is the dominant shrub species which is restricted to the southern paramos of the Colombian Cordillera Oriental (GleeÂŁ 1979b). Sphagnum bog taxa are common in the Aragoetum abietini and together they altain a considerable cover . Other frequent species include

Ner ter a depr essa, Pernettya pros t rata, CampyZopus pittieri, CZadia aggr egat a and Metz ger ia sp. The number of species varies from 19 to 51 in 7 releves and is lowest in Sphagnum bog (subass. puyetosum ). Common epiphytic cryptogams are Maar omitr ium Zongifolium, Zygodon r einwar dtii , DaZtonia sp. (6412c), FruZZania ZobuZo- hastata, F. sp. (5398), Metzger ia dor sipar a, RaduZa ramuZina, Br aahioZejeunea ZaxifoZia, Usnea sp. and Oropogon Zoxensis .

159 Dominance o f the single (select.) cha racter spe cies Aragoa abietina distinguishes this association from rel a ted Xyris bog communities . The Ar agoetum abietinae includes two subassociations , e asily recogn i zed by the presence or absence of e .g. bamboos. Synec ology : The Aragoetum abietinae is a rar e shrub associati on on boggy slopes (up t o 20° inclination) and on gently sloping or l evel Sphagnum bog . The habita t is moist and cool , and is pre sent both in the bunchgrass and i n the bamboo pa r amos Soils are humi c, clayey and 70 em to more than 120 em de ep . The uppe r soil laye r i s strongly to moderately a c id (pH 4.3 to 5 . 1 in 7 rel eves) . Succession t owa rds the Ar agoetum abietinae starts with (Xyris-) Sphagnum bog and probably als o with the Sphagnum Br euteZia - SwaZZenochZoa community (10) . Future po llenanalys e s of soil and peat bog s e quences under stands of the Aragoetum abietinae may provide more information about the suc cession . Cavia porceZZus, SyZviZagus brasiliensis and frog s are the most c ommon vertebrates ob s erved in th i s vegetation t ype . Distribution : The Ar agoet um abietinae is only known from paramos near Bogota between 3480 and 3700 m. Phytogeographic comment : The woody scrophulariaceous g enus Aragoa is endemic to the par amos of Col ombia (except the Cor dillera Central and the Venezuelan Sie rra Nevada de Merida. Aragoa is an old paramo genus , which wa s r e porte d by Van der Hammen et al. (1973) for the olde st paramos in the area at the Pliocene-Ple i stocene Boundary . On the oasis of it s peculiar morphology, Pennell (1937) and Menneg a (1974) consider as the neare st r e latives members of the Veroniceae . The ColomBian Cordillera Or i ental and especi a lly its southern par amos, wliere t, of the 8 descriBed sp e cie s· are found with the maximal sub generic morphological dive rs-ity must fie c onside red as the main centre of evolution of this intere sting genus (Cleef 1979° , Fig . I) . note : Othe r Aragoa species also may dominate ve getat i on t ypes i n the study area . Thus , Aragoa dugandii also represents a prop e r oog community on the wet eastern slopes oetween LaRe Tota and the Si erra Nevad a del Cocuy (30 30 - 3550 m)_. Aragoa dugandii is a rare endemic species , and hence this community is scarce a lso . Aragoa per ez- arbeZaeziana is a shruB or dwarf tr e e , attaining considerable c ove r in timberline bush or dwarffore st in the Pa r amo de Sumapaz (see 101). Aragoa cupressina is zonal in subparamos near Bogota and in grassparamos in the Par amo de la Rusia and Paramo de Guantiva ( 2800- 4000 m}. Aragoa Zycopodioides is zonal at wet timberlines , and is also f ound in zonal thickets in the bamboo paramo (3000- 3900 m) . 72a . Subass . swaZZenochZoetosum subass. nov . t ype : r e l . 149 ; t a ble 14 . Physiognomy : The se scrophulariaceous thickets contain bamb oos , about 2 m hi gh. Se e a ls o under the a s so c iation . Composition & syntax onomy : SwaZZenochZoa tesseZata, LachemiZ Za spp. (5375B , 5376 , 5383) , EspeZe t ia grandifZora, Berber is sp . and Bartsia sp . e .g. are differential against the puyetosum. Several spec ies from the surrounding zona l vegetation are present , and therefore the number of specie s (39 - 51 in 2 releves) is higher than in the puyetosum. With more releves available the lower bamboo paramo and the subparamo stands may be expected to be distinguished as altitudinal variants of the swaZZenochZo et osum. Synecology : Patches of this unit may be present on wet sloping ground (12 - 20° inclination) in (slight) depressions. The phreatic level was found at about 15 em below surface . The profiles are not deeper than I m and consist of humic black clay in the upper layer (pH 4 . 3- 4 . 6) . The d a rk grayish lower pa rt

160 contains more s and and pebbles. Distribution: The swaZZenochZoetosum is not common and only known from the bamboo par amos near Bogota (Palac io, Chuza - Cruz Verde ) between about 3480 and 3700 m. The lowermost stand (re l . 59) is in the subparamo. 72b. Suba ss . puyetosum subass . nov . typ e : r e l. 197; table 14; Fig. 71 & 78 Phy sio gnomy: This climax scrophulariaceous shrub with a thick bryophy te layer is present on former Sphagnum bog or on peaty soil. Composition & syntaxonomy: Presence and hi gh cover (3 - IS %) of Puya santosii, P. cryptant ha and probably also of P. trianae are, combined with the absence of bamboos,the ma in dif f erential feature s . Other differential taxa are

Espeletia chocontana, V.accinium floribundum var . ramo s issimum~ Campylopus tunariensis and Bryum biZZardieri . Weak differential species are Xyr is acuti f olia, CZadonia boliviana, Cladonia colombiana and Gongylant hus innovans . The number of sp ecie s is lower than in the swaUenochZoetosum and v aries from 19 to 38 in 5 releves . Synecology : Rel. 197 with an abundance of Pleurozium schr eberi and dwarfed Ericaceae (Perne t t ya, Vaccinium ) marks the end of the suc cession beginning on Xyris - Sphagnum bogs. A drier, shady habitat is pres e nt near the trunks of Aragoa and contains Pleurozium schr eberi, Hypnum amabile, Metzger ia s p., Bryum biZZardier i, Gongylanthus innovans and Peltiger a sp . Most of these speci e s cover the raw needle litter of Aragoa abietina . Campylopus t unar iensis is frequent on organic r emains, e .g . of Puya . The succession from open Xyris - Sphagnum peat t o the Aragoetum abietinae puyetosum is de scribed under Sphagnum bogs . The puyetosum covers ex tensive areas on level peat bog , but also on sloping Sphagnum bog in small wet valleys and on boggy ground. The bl ack upper peat layer is mode ratel y a cid (pH 4.7- 5.1) and the peaty to clayey substra tes are about I m (mineral soil) to 4 m (Sphagnum bog) deep. Cavi a porceZZus is common; a pattern of trails is fo~nd on the Sphagnum peat. Distribution: The puyetosum is only known from the (lower) bunchgrass paramos north of Bogota between Neusa and S. Cayetano at about 3650 - 3680 m near the Laguna Verde, where Aragoa abietina thickets cover several hectares. The Aragoetum abietinae was also observed in the headwaters of Rio Salto some km north of the Laguna Verde. note: The paramos near the Laguna Ve rde be twe en Neusa and S. Cayetano st and out by the presence of well-dev e loped Aragoa abietina bush, which is sca rce to absent in other paramos near Bogota. The same applies to the Senecionetum nitidae (84) and the Lorenzochloetum erectifoliae (106). The Calamagr ostis effusa - Espeletia (E. barclayana, E. argentew vegetation is one of the best ex amples of the characteristic, well-deve loped, lower bunchgrass paramos in the Colombian Cordillera Oriental . It seems important to establish a small National Park in the paramos between Neusa and S. Cayetano including this vegetation. This would also protect the catchment areas of the Neusa barrier lake. 73 . Senecionetum andicolae ass. nov . (prov.) t ype: rel. 255; t able 14; Fig. 72 (also Fig. 12) Physiognomy: This microphyllous Compositae shrub possesses grayish foliage and yellow flowers. Stands are structured in: I} a closed shrublayer in well-developed thickets up to 2.5 m high, with b amboo up to 130 em high;

161 2) layer of Cyp e raceae and Juncaceae, up to 70 em high with a cover of 25%. a few grasses and dwarfshrubs are present; 3) a layer of mainly pleurocarpous mosses, 10-15 em high. Composition & syntaxonomy: Senecio andicoZa dominates the asso ciation. This woody species is distributed from northern Ecuador to Venezue la and Costa Rica between 3200 m, from the forest line up to 4400 m in the s uperparamo. Other conspicuous taxa are SwaiZenochZoa tess?Zata, Carex pichinchensis, Sphagnum sancto-josephense, Rhynchospora macrochaeta, LuzuZa gigantea and PZeurozium schreberi. (The approximate number of species in rel. 255 is 36). The recognition of the Senecionetum andicoZae as a distinc t thicket association on boggy paramo ground is based on dominance of Senecio andicoZa which is a selective charac ter species. The association is tentatively describ ed as more releves are needed. The Senecionetum andicoZae has some species in common with Sphagnum bog communities, but it has the greatest aff inity with the Hypericetum ZaricifoZii (74), as indicated by the species Sibthorpia repens, LuzuZa gigantea, PZeurozium schreberi and (juvenile) Hypericum Zaricifolium (see table 14). Synecology: Senecio andicoZa is a species with a wide eco logi ca l ratlge. Senecionetum andicoZae bush is loca lly common on sloping (5 - 10째) boggy gro und along paramo streams . Pur e Senecio andicoZa thicke ts are not common in the s tudy area. Mostly, other woody composite species may be associated e.g. Senecio ' vaccinioides, DipZostephium aZveoZatum, EspeZetia incana and E. Zopezii. On the other hand, Senecio andicoZa is often present in other paramo shrub, for example in the DipZostephietum revoZuti (71), Hypericetum ZaricifoZii (74) and Senecio vaccinioides . Weber (1958) reported Senecio andicoZa from Costan Ri can paramo thickets and together with Senecio firmipes Greenm., DipZostephium costaricense Blake (D. aZveoZatum is probably a synonym), Hypericum siZenoides Juss., Myrtus oerstedii (Berg) Hemsl. and Berber is nigricans Kuntze. The profile in rel . 255 consists of a peaty clay, moderately acid (pH 4.9) in the the top layer . In higher places, the soil is thinner . Observed were foraging activities by Cavia (or SyZviZagus ) indica ted by grazed young bamboo and LuzuZa gigantea . Distribution: The Senecionetum andicoZae is only known from the paramos of Boyaca (Rusia , Pisva, Cocuy) between 3600 and 4000 m. The assoc iation may be expected in other paramos where the species is present. Note: Low Senecio andicoZa shrub was also noti ced in open bog vegetation with MyrteoZa oxycoccoides and dense mats of bryophytes (AtractyZocarpus sp., Sphagnum sancto- josephense, Ditrichum cf. capiZZare, Nardia succuZenta, PseudocephaZozia quadriZoba) surrounding hot springs in the wet Andean cloudforest at 3280 m on the volcano Purace in the Colombian Cordillera Central. Senecio andicoZa is dominant in the shrublayer in zonal Gynoxys tolimensis dwarffores t with NeuroZepis aristata in the wet upper Andean forestline (3800- 39 00 m) on the W slope of the Parque Los Nevados located farther north in the same range (Cleef et al. , in press). shrub of Hypericum spp. Spec ies of the section Brathys (Mutis ex L.f .) Choisy determine the hypericaceous shrub in the study area. 74. Hypericetum Zaricifolii ass. nov . type: rel . 262; table 14; Fig. 73 (also Fig. 26) Physiognomy: Well-developed stands of this t a ll hypericaceous shrub with slender twigs, leptophyllous leaves and bright yellow flowers are structured in: I) a shrub layer, up to 3-3.5 m. Th~ cover of the canopies is about 100%;

162 2) an open high herb-dwarfshrub layer (up to 20% cover) , possibly including a few bamboos ; and 3) a thick (3-25 em) ground layer , consisting of low, creeping herbaceous species and/or mosses ; this is the most conspicuous stratum under the shrub canopy . Composition & syntaxonomy : Hypericum laricifolium ssp . laricoides is a dominant and selective character species. According to Dr . N.K.B. Robson (in litt.) Hypericum laricifolium is widely distributed in the high tropical Andes from Peru to Venezuela . The ssp . laricoides (previously H. laricoides Gleason) is restricted to the Venezuelan Sierra Nevada de Merida and the Colombian Cordillera Oriental between 2900 and 4200 m. Sibthorpia repens is a preferential character species,optimumally developed here . The Andean distribution is about the same as that of Hypericum laricifolium (Hedberg 1955) . Other common taxa are

Thuidium peruvianum, Hypnum amabile, Peltigera dolichorhiza, P. pulverulenta, Rubus sp., Niphogeton dissecta, Oxylobus glanduliferus, Leptodontium luteum, Orthrosanthus chimboracensis, Geranium sibbaldioides and Pernettya prostrata., The average number of species is 40 (36 - 45 in 4 releves). Except in the densest and most shady stands (e . g . rel. 236) , epiphytes are numerous . Usnea sp . (2275) and Ramalina sp . (2290) are abundant . Common are Oropogon loxensis, Frullania sp, (2286), Metzgeria sp . (2292) Hypotrachyna

caracacensis, Cora pavonia, Parmotrema arnoldii, Everniastrum catawbiense, Leptogium sp ., Brachiolejeunea nitidiuscula, Holomitrium sp . (2282) and Colura patagonica . The closest relationship is shown to the Senecionetum andicolae (73) and it seems that edaphic factors, particularly the phreatic level , determine which of the two associations develops. The stand on peat (rel . 263,' 263A) may represent a variant with presence of Halenia gigantea, Cinna poaeformi, Valeriana cf. longifolia, and Swallenochloa tesselata as main differential species . This variant is not described, because the two releves comprise two parts of the same stand . More releves from other localities are required for a further subdivision . Synecology : The Hypericetum laricifolii is restricted to small humid valleys and depressions supplied with run-off water from a minor catchment area . The shrubs grow mostly on poorly drained humic sandy to clayey soils, which do not dry out in rainless periods . The shrubzone is only a few meters wide and develops downslope like strips along the small waterlogged valley floors . The slopes are 3- 18째 . On level wet peaty ground , Senecio andicola shrub may replace the Hypericetum laricifolii. The black to brown sandy clayey soils , conta~n~ng many roots, are 50 to more than 120 em thick . The upper soil layer is moderately acid (pH 4 . 4-5 . 5) and is covered by an Aoo-layer of 2-3 em thickness . In the dense shady stand of rel . 236 bare raw litter of Hypericum laricifolium covers about 60% Rel . 51 contains a low herblayer dominated by Azorella multifida and Sibthorpia repens. Other conspicuous species in this layer are Thuidium peruvianum, ,Arcytophyllum muticum and Stachys elliptica. This stand provides shelter for cattle, the effects of which are shown by the presence of Rumex acetosella and Acaena elongata. Part of this stand was damaged by cutting for fuel. Near r,el. 236 , at about 3500 m in the Paramo de la Rusia, a vegetation succession was studied about one year after burning . Under the scorched stems of Hypericum laricifolium photophytic species have a cover of about 85%, against 3% in rel . 236 . Orthrosanthus chimboracensis and Eleocharis stenocarpa were abundant, accompanied by Senecio formosus, Rhynchospora macrochaeta and Valeriana vetasana. Stand on wet peaty ground (rel . 263, 263A) contained e.g . Swallenochloa tesselata,

Cinna poaeformis, Halenia gigantea, Pleurozium schreberi, Blechnum loxense, Valeriana cf. longifolia and Juncus echinocephalus. Cavia porcellus is common in the Hypericetum laricifolii (hiding, foraging) . Distribution : The Hypericetum laricifolii is probably widely distributed in the Colombian Cordillera Oriental from the upper forestline up to 3800 m.

163 Releves in the study area from the southern end of the Paramo de la Rusia. The association was further observed in the Paramo de Palacio and Sumapaz at 3700 m. The association may also be present in the Vene zuelan Si erra Nevada de Merida, as Dr. N. K.B. Robson (in litt . ) reported the ssp. Zaricoides also from these high mountains. 75 . Community of Hypericum Zar icifolium ssp . Zar icifolium

Hyper icum Zaricifo lium ssp. Zar icifolium is widely distributed in the high tropical Andes from Central Peru to Venezuela (Dr. N.K . B. Robson , in litt . ) . In the Colombian Andes this subspecies is present in zonal timberline shrub (Cuatre casas 1934, Cleef et al., in press) or in paramo rockshelte r bush be twe en boulders. In the Sumapaz paramo at 3580 m near the Laguna La Primave ra, a stand in a rockshe lte r was studied (rel. 12). On a bouldery slope (up to 15掳) Hypericum shrubs and small trees up to 6- 7 m hi gh have a cover of 70% . Other cha rac t e ri s ti c shrubs or dwarf trees common t o upp e r Andean dwarf for e st a r e Miconia salicifolia, Ber ber i s sp. Senecio andicola, Or eopanax mutisiana, Acnistus quitoensis, Eupator ium (Ager atina) glyptophlebium, Cestrum parvifolium and Gaultheria r amosissi ma; also lianas, e .g. Valer iana pavonii and Muhlembeckia thammi f olia are present. Herbace ous speci e s include Epidendrum erosum, Oxalis cornuta, Cerastium subspicatum, Myrr hidendron glaucescens , Peperomia hartwegii, Luzula gigantea, Gr eigia cf. mulforfii , Niphogeton ternata var. ternata , and some Polypodi aceae. Herbertus subdentatus (l a r ge form) c overs ab out half of the ground l ayer. Associated are Plagiochila ovata, Bartramia angustifolia, Plagiochila pachyloma, Anas trophyllum nigrescens, Lepidozia squarrosa and Campylopus pittieri . Usnea sp. (967) is the most common and conspi cuous Hypericum stem epiphyte. Other common epiphytes are Frullania sp. (980), Parmeliaceae and Radula r amulina with its two varieties (Jans 1979). The open charact e r of this Hypericum stand permits the growth of Calamagrostis effusa ( c over 30 %) between the boulders. In the site of rel. 12 at the base of the scree this hypericaceous shrub is gradually replaced by Escallonia myrtilloides dwarfforest.

Other hypericaceous communities Several other communities, each of which dominated by a di f f e r e nt woody s peci es of Hypericum, were observed in the 路 study area. Only brief descriptions will be pre sent ed with notes on physiognomy, composition, ecology and distribution. 76. Shrub of Hyper icum Zycopodioides Thickets up to 2.5 m high of this leptophyllous species are apparently cfimmon in the subparamos on the humid eastern side of the Colombian Cordillera eriental . They were observed e . g . between 3250 and 3700 m in the headwaters of Rio Casanare in zonal and azonal habitats. Hyper icum lycopodioides was hardly collected in the past. Its habit resembles that of H. lar icifolium, but the leaves are distinctly larger . 77. Shrub of Hyper icum magniflorum Patches of these nanophyllous shrubs (1.0-1.5 m) were obs erved in the headwaters of Rio Casanare between 3000 and 3350 m. They are found on azonal boggy ground in the lower part of the bamboo paramos commonly associated wi th Espeletia lopezii, Senecio cacaosensis and SWalZenochZoa . Hyper icum magniflorum is endemic to the northern portion of the Colombian Cordillera Oriental. 路

164 78. Shrub of Hypericum goyanesii High leptophyllous thickets (2-3 m) of this species are only known from lower paramos near Bogota (Cruz Verde, Guasca, Guerrero) between 2700 and 3500 m. Lozano & Schnetter (1976) reported pure stands of Hypericum goyanesii at 3400 m in the Paramo de Cruz Verde, which they consider as secundary vegetation; they observed that this species is very sensitive to damage by fire. The same authors observed a vegetative growth of broken twigs of Hypericum goyanesii . This can be confirmed by the present author . Hypericum goyanesii, however , is mainly found scattered in subparamo shrub formations and dwarfforests (e . g. Lozano & Schnetter 1967, table 9) . 79 . Shrub of Hypericum thuyoides High leptophyllous shrubs (1-3m) of Hypericum thuyoides occur in the forest line and the lower part of the paramo belt (3000-3600 m). Pure stands of this species are locally present on boggy valley floors (e . g . in the headwaters of Rio Guandoque) . With its preference for humid peaty soil and in its habit this species resembles Hypericum laricifolium ssp . laricoides . Hypericum thuyoides shrub is an important element in shrubby communities and dwarfforests in the bamboo paramo with Vaccinium floribundum and Bucquetia

glutinosa . 80 . Shrub of Hypericum humboldtianum Shrubby (subserial ?) vegetation of Hypericum humboldtianum (including H. jussiaei) is present in the subparamo and open places of the upper Andean forest belt (2500-3200 m) near Bogota . The collections by Dr . J . Cuatrecasas (nr . 25) and Dr . E. Killip (nr . 34178) were made in thickets and low shrub, according to the labels . 81. Shrub of Hypericum trianae and Senecio vaccinioides Low Hypericum trianae - Senecio vaccinioides shrub is only known from the humid W side of the Paramo de Guantiva . One stand was analysed at 3870 m in the Q. Minas valley (rel. 32) in the same physiographical setting as described for the Senecionetum nitidi (84) . The rale Hypericum trianae is only 30 em high; while Senecio vaccinioides is 1-1 . 5 m high . Leptodontium pungens is dominant in the moss layer . The thin (40 em) humic clayey soil is strongly acid (pH 4 . 1) . 82. Dwarfshrub of Hypericum juniperinum

Hypericum juniperinum (previously H. brathys) is a common leptophyllous dwarfshrub in the northern Andean paramos (Ecuador, Colombia , Venezuela) between 2650 (2200) - 3700 m. Hypericum juniperinum dwarfshrub vegetation, apparently is a final stage in the secondary succession on former potatoe fields, e . g . in the northern part of the Paramo de Sumapaz . Hypericum juniperinum dwarfshrub is successional to the Rumex acetosella vegetation, which covers the bare field after harvest . Here in the Paramo de Chisaca at about 3600 m, a Hypericum juniperinum stand was found (rel . 132) in a small, slightly humid valley floor , where potatoes had been raised 7 years before according to residents. The H. juniperinum dwarfshrub was about 80 em high and had a cover of about 65% . Scarce 50-100 em high sternrosettes of Espeletia grandiflora and some tussocks of Calamagrostis effusa were already present also. Apart from herbs , prostrate Arcytophyllum muticum covered almost half of the ground layer . The moss layer of Breutelia spp . (4926 , 4928) had a cover of only 8% .

165 The humi c c layey soil contaLnLng nume rous annelid wo rms wa s about 100 em thi ck, and the pH in the top so il l aye r was 4.4. 83. Other hypericaceous shrub and dwarftree vegetation Some more species of the section Brathys of Hypericum may form genuine hyp e ri caceous communities: e.g. Hypericum pheZZos, which is a dwarftree and shrub in Andean forests and lower paramos (2600-3800 m) in the northern part of the Colombian Cordillera Oriental; the same applies to Hypericum cuatrecasasii, a species very close to H. goyanesii, from the forest line near Arcabuco. This and other hypericac e ous vege tation types have not been studied in deta il , since they are primarily part of the high Andean forest vegetation, which falls outside the scope of this study .

84. Senecionetum nitidi ass. nov. t ype: rel. 189 ; table 14 . Physiognomy: Well-developed stands (e . g. rel. 189) of this nanophyllous composite shrub with dark-gr eenish brilliant , revolute foli age and yellowish inflorescences, are structure a s follows : I) a dwarfed shrublayer, 1-1 .5 m, the cover of which may be as high as 70% ; 2) a herbaceous layer, mainly of grasses, about 40 em high; cover 90%; and 3) a predominantly pleur ocarpous mo ss layer, with a cover of about 20% . When 'there i s cattle grazing, (e.g. r el. 99), the cover of the shrub layer i s about 10%. The cover of the pleurocarpous mosslaye r is about 80%. Under gr az ing most of the tuss ocks are replaced by cypera ceous and graminoid tufts and prostrate dwarfshrubs. Composition & syntaxonomy : Senecio nitidus is the dominant and exclusive characte r s pecies. Other fr e quent (and partly diagnostic) species are CaZamagrostis effusa, PZeurozium schreberi, Carex cf. conferto- spicata (6126A) , LorenzochZoa erectifolia, Poa cf. paucifZora (6123, 4129A) , PaspaZum

bonpZandianum, Niphogeton gZaucescens, Carex bonpZandii, ArcytophyZZum muticum, HaZenia sp. (6127, 4134) , Sphagnum compactum, CZadia aggregata, CampyZopus aZbidovirens , CampyZopus pittieri and AnastrophyZZum Zeucostomum. Epiphy tic cryptogams are s car ce: e.g. Metzgeria dorsipara, Parmeliaceae, Usnea sp.,Lejeuneaceae, Sticta sp. (6139). LorenzochZoa and Poa cf . pauciflora were not observed in o ther shrubby communitie s at this height . The greatest affiniti es are with the Senecionetum andicoZae (73) , the Hypericet um Zaricifolii ' (74) and the azonal Senecio vaccinioides shrub (81, 96). Synecology: This type of c omposite shrub is founq in moist to humid valleys in the lower bunchgrass paramos , where water collect s from the catchment areas. Slopes are up to 7째 . The phreatic level is at a depth of 10-15 em . The humic black, clayey soil is 60-90 em thick and its upper layer is (strongly to) moderately acid (pH 4 . 6). The Aoo-layer is up to 5 em thick . Distribution: Senecio nitidus occurs as a shrub or dwarftree only in par amos near Bogota between 3000 and 3700 m. The association is rare and has only been described from . the paramo s between Neusa and S. Cayetano (3600-3700 m).

166 85. Senecionetum vernicosi ass. nov. type: rel. 281; table IS; Fig. 29. photo: Gradstein et al. 1977, plate 2D lit.: Cleef et al., in press. Physiognomy: Well-developed stands of these green-grayish microphyllous composite shrub with pale yellowish flowers are structured into: I) a shrub l ayer 1-2(3-5) m high, with a cover of 50-80%; 2) a herbaceous layer generally with a low cover. In upper grass-paramo stands, bunchgrass es may penetrate the Senecionetum vernicosi and have a cover of 50% (in the understorey); and 3) a thick bryophyte layer, dominated by mosses; the covers is 50-100%. Liverworts are prominent in the ground layer (up to 40% cover) under the permanently humid conditions of the upper condensation belt. Composition & syntaxonomy: Senecio vernicosus is a selective character species, endemic to the paramos of the Colombian Cordillera Central and the Paramo de Sumapaz, between 3600 and 4350 m. Frequent and characteristic species are Leptodontium wallisii, Lachemilla holosericea, Peltigera dolichorhiza, Azorella multifida, Geranium sibbaldioides , Cora pavonia, Bryum sect.

Rhodobryum (?), Senecio formosus, Oreomyrrhis andico路l a, Campy lopus cavi fo lius, C. pittieri, and Carex tristicha. True superparamo taxa are Lachemilla tanacetifolia, Draba sp. (1300, petals yellow), Valeriana plantaginea, Lachemilla nivalis and Breutelia lorentzii. Species of bryophytes are dominant in the groundlayer: e.g. Campylopus sp. (8093) and Plagiochila triangulifolia in the most humid stand on the Nevado de Sumapaz; Leptodontium wallisii resp. Campylopus sp. on the Nevado Ruiz (4130 m) and S. Rosa (4350 m) in the Colombian Cordillera Centra l. Plagiochila cleefii, a skiophytic species, is only known from the Nevado de Sumapaz. Only a few specimens of our Plagiochila collections have been identified, and this new species is likely to occur in other parts. Some epiphytic mosses may be present on Senecio stems. For the present diagnosis of the Senecionetum vernosi , data (Cleef et al. in press and unpublished) from stands in the Cordillera Central) have been used. Table 15 Senecionetum vernicosi ass. nov. 281 releve nr. 2 18 releve area m 3 slope (degree) 70 cover % shrub 12 herbs 55 mo sses 40 liverworts 39 approx. number of species si soil >120 depth em 5.0 pH top soil 4050 alt. m. Sum locality cover % ~--Senecio vernicosus 70(x) Plagiochila triangulifolia 35 40(x) Campylopus c Leptodontium wallisii S(x)

...

Plagiochila cleefii Azorella multifida Breutelia chrysea Herbertus subdentatus Cora pavonia Satureja nubigena Lachemilla holosericea Carex cf. tristicha

10(x) 10 2

2(x) 1

<I (x) <I

Oreomyrrhis andicola Draba sp. (1300, yellow petals) Bartsia sp. Geranium confertum Geranium sibbaldioides Cerastium sp. Lachemilla nivalis Senecio formosus (juv.) Azorella crenata Laestadia muscicola Luzula gigantea Pernettya prostrata Grammitis moniliformis Acidodontium cf. megalocarpum Thuidium peruvianum Riccardia squarrosa Breutelia lorentzii Bartramia angustifolia Peltigera dolichorhiza

..;I (x) I

<I <I+ <I (x)

<I <I (x) <l+(x)

<I I

<I <I <I I (x) I I

<I <I <I (x) <I <I <I

Bryoideae (8046) pleurocarpous moss (8049) Lophocolea spp. (8037, 8044) Anastrophyllum sp. <.I Syzygiella sp. (8045a)b <I <I Chiloscyphus sp. (8045 ) Lachemilla sect. Lachemilla (8034b)<l

167 (x) Species in common with stands in the Parque Los Nevados, Cordillera Central . Synecology : The composite thickets of the Senecionetum vernicosi are present on humid soil in the upper bunchgrass paramo and lower superparamo . The Senecionetum vernicosi is well developed in protected sites in small valleys and ravines along the grassparamo-superparamo boundary. Scattered Senecio vernicosus shrub is also present in the zonal upper bunchgrass paramo , especially on the high volcanoes in the Parque Los Nevados (Cleef et al., in press) . The cover becomes higher towards the lower limit of the superparamo . High Senecio vernicosus shrub occurs also on azonal boggy ground in the grass paramo of the Paramo de Surnapaz , where it is common in SWallenochloa-Breutelia bog (10) with cushions of Oreobolus obtusangulus and Eriocaulon microcephalum. These locations have many species in common with the type releve . The studied sites were located in watershed areas at 3800 rn on the Cuchilla Los Frailes , 3 krn NE of Alto S. Agustin , and at 4000 m on the Cuchilla La Rabona (rel . 503) . The grayish-brown silty soil on calcareous bedrock is about 1 rn thick , the upper layer is moderately acid (pH 5 . 0) , and is rich in organic content. In other places , the Senecionetum vernicosi is found on sandstone and volcanic bedrock. Distribution: The Senecionetum vernicosi is found at 4000-4100 m on the Nevado de Surnapaz in the Cordillera Oriental . Similar stands may be common between 3800-4100 m in all high watershed areas of this vast pararno . The Senecionetum vernicosi is also present in the Colombian Cordillera Central, e.g. between 4100 and 4350 rn on the volcanoes in the Parque Los Nevados (Cleef et al., in press) . 86 . Cortaderio sericanthae - Arcytophylletum caracasani ass. nov. type : rel . 407; table 16 ; Fig. 74 (also Fig. 75) lit. : Vareschi 1980 Physiognomy : This rale , leptophyllous , dark olive-green, rubiaceous shrub with rounded dense canopies and conspicuously shiny yellowish-orange stipulae , white or faint-lilac flowers and twisted stems. Most of the rubiaceous shrubs or dwarftrees have twisted sterns with seasonal rings (probably reflecting) dry periods with water stress . In well-developed stands the following layers can be recognized: 1) an open , rale shrub layer (0 . 5-2 m), whit a cover of about 50% ; 2) a herb-dwarfshrub layer up to 50 em, with a cover of 5-40%. Grasses are the main component ; 3) a cryptogamic ground layer , with a cover of 10 to 40% , predominantly consisting of mosses and lichens. Composition & syntaxonomy : Arcytophyllum caracasanum is a (selective?) character species , with a cover of 30% or more . In contrast to Steyermark (1971), the present author considers A. caracasanum (or : A. nitidum ssp. caracasanum var . culmenicolum) as a valid species that differs morphologically from A. nitidum (ssp . nitidum, sensu Steyerrnark 1971) as well as ecologically, at least in the Colombian Cordillera Oriental . Acrytophyllum caracasanum var. culmenicolum is found in the Colombian Cordillera Oriental between 2500 and 4050 rn , as far as the Nevado de Huila 3000-3600 m and the Sierra Nevada de Merida up to 4300 rn (Steyerrnark 1971); together with the var. caracasanum it occurs on the highest peaks of the Cordillera de la Costa above Caracas (Steyerrnark & Huber 1979) . For other character species reference is made to table 16 . Common taxa in our study area are Oreobolus obtusangulus ssp . rubrovaginatus, Cortaderia sericantha, Carex aff. conferto-spicata, Gentianella corymbosa, Bartsia sp.

Calamagrostis effusa, Rhacocarpus purpurascens, Campylopus richardii, Jamesoniella rubricaulis, Siphula spp ., Cladia aggregata and Cladonia isabellina,

168 Table 16.

Cortaderio- Arcytophylletum caracasani ass. nov. 86b

sub ass. ( prov.) releve nr. releve area m2 slope (degree) cover % (dwarf)shrub grasses (bamboos present) mosses liverworts lichens soil depth em (max.) soil pH top soil approximate number of species alt. m locality

247 16 3 75

261 20 20 37

407 35 30 30

5 8

20 8

4 2

27 5 g/s

239

383

25 13 50 15

36 12 13 27

2 10 Cjg g/s 4.9 5.0 4.7 5. I 42 33 53 43 35 3725 3820 3605 3935 3605 Rus Rus Min Rus Arn

10 csg 5.0

15 Sg

c c c c c

cover % c-&-d-taxa Arcytophylletum car.

Arcytophyllum caracasanum Cortaderia sericantha Oreobolus obtusangulus ssp . rubro- vag. Carex aff. conferto-spicatae Rhacocarpus purpurascens Campylopus richardii Jamesoniella rubricaulis Cladonia isabellina Bartsia sp. Calamagrostis effusa Siphula spp . Cladia aggregata Gentianella corymbosa Diploschistes sp. Puya trianae c Diplostephium colombianum Racomitrium lanuginosum Racomitrium crispulum Andreaea rupestris c Hypericum tetrastichum Arago~

cupressina

Toninia sp. Geranium multiceps Gnaphalium antennarioides Castratella piloselloides Rhynchospora paramorum Pterichis galeata Paepalanthus paramensis Xyris acutifolia Espeletia congestiflora Hypericum strictum SWallenochloa tesselata Grammitis moniliformis Sisyrinchium pusillum c Hypericum garciae Leprocaulon albicans

5 25

10 3

<I+

<I I+

5 3

<I <I <:I

<I+

<I I+

<I <I

I .(.]+

.(1+

<I <I

<.I <I I

<I+

10 <.1+

<I <I 2 25 2

<I+ <I

35 10 5

<I <I <I

<I <I

<.I+ I

<I+

<.I

<1 <1 1 2

35 <1

<I <.I+ <I+

<I <I

<I+

J69 (247)(261)(407)(239)(383)

Disterigma empetrifolium Halenia sp. (p) Leptodontium pungens Alectoria ochroleuca Carex pichinchensis Cora pavonia Spiranthes vaginata Espeletia grandiflora ssp. boyacensis Stereocaulon atlanticum Cladonia boliviana Oritrophium peruvianum Herbertus acanthelius

<I+ <I <I <I

<I <I <I <I

<: I

<I+ <I

<I <I <I +

<I <I

Other taxa:

Lycopodium contiguum <I ..:I+ <I+ Pernettya prostrata I+ Castilleja integrifolia I Rhynchospora macrochaeta <I Lepidozia s p.(p) <I Vaccinium floribundum var. ramosissimum <I Agrostis haenkeana Riccardia sp.(p) <I ..::!+ Anastrophyllum leucostomum ..:I Herbertus subdentatus <I Diplostephium phylicoides <I Vaccinium floribundum var. marginatum Harpalejeunea sp. ..:I+ Hypericum laricifolium 2 ..:I+ Bartramia angustifolia Gaultheria ramosissima Calamagrostis bogotensis Aongstroemia julacea Thamnolia vermicularis Campylopus pittieri Cladonia miniata Cladonia poUa Cladonia confusa Cladonia rangiferina var. abbayesii Cladonia colombiana Hesperomeles pernettyoides Lupinus sp. Sphaero~horus melanocarpus

..:I I "'I 2 10

..: I I 3

<I <I <I <I ..:I <I 2

<I <I+ <I

Cortaderia sericantha is widely distributed in open vegetation in the paramos from E'cuador to Colombia and Venezuela and in the study area on mineral soil and in sandstone crevices from the forest line up into the superparamo a t 4350 m. Carex (aff.) conferto-spicata (e . g. 6990) seems to be related to the low sedge species C. tristicha (Dr. T. Koyama, in litt.). Carex tamana Steyermark is probably synonymous. Diplostephium columbianum may be an associated endemic low shrub in the northern paramos of our area. Some endemic species of Hypericum also are associated , e.g. H. tetrasticha and H. garciae. Synecology: In the study area, the Cortaderio-Arcytophylletum caracasani is found in bamboo paramos . The open shrubby Arcytophyllum caracasanum vegetation is found in crevices or patches with soil in areas with e.g. "lajas" and "roche moutonnee". Such high altitude species as Diplostephium colombianum and Cortaderia sericantha find their habitat in these places. A number of taxa from the thin stony soils in grass paramos is present also: e.g. Campylopus richardii, JamesonieZZa rubricaulis , Herbertus acanthelius,

170

Carex conferto- spicata, Siphula spp., Diploschistes sp., Leprocaulon congestum, Puya trianae, Espeletia congestiflora, E. annemariana var. rupicola, Racomitrium Zanuginosum, Racomitrium crispulum, Stereocaulon atlanticum and Oreobolus obtusangul us . Most of these species have their optimum in the bamboo paramos. The lithosols are moderately acid (pH 4.7-5.1 in 6 releves). The clayey to sandy dark brownish thin soil in the rock crevices retains the moisture for a longtime. Species of Dysdercus are common. Transpiration probably is reduced at these sites with shallow soil since the plants possess clear xeromorphic features such as imbricate leptophyllous leaves (ArcytophyZZum caracasanum), cushion form (Oreobolus), and blackish colours in mosses, the leaves of whi ch have a hyaline hairpoint (Campylopus richardii and Racomitrium spp.). Species as JamesonieZZa rubricaulis, Herbertus subdentatus, H. acanthelius (all liverworts) and the lichen Leprocaulon albicans thriye because of the permanent fog and are excellent indicators for humid conditions. Apparently these species persist during short dry periods. Distribution: In the study area the Cortaderio-ArcytophyZZetum caracasani is present in bamboo paramos from the forest line up to 4050 m. The releves are from the central part of the Cordillera Oriental (Guantiva, Rusia, Tota) between 3600 and 3950 m. According to herbarium data ArcytophyZZum caracasanum is present on the southern slopes of the Paramo de Sumapaz (Cordillera de Los Cruces) between about 3400 and 3650 m (Fosberg 20859, 20903- US), in the northern paramos of the Cordillera Oriental (Santurban, Romeral, Tama) and in the Paramo de Guasca where Fosberg (21698 US) reported this species as a common shrub on ridges (3500-3 600 m). Vareschi (1970, 1980} reports ArcytophyZZum caracasanum shrub from screes up to 4 100 m in the Sierra Nevada de Merida, Venezuela. Associated species are Ottoa oenanthioides HBK, GyrioXYB violaceae Sch.Bip. , Aragoa and VaUea ; or with Valeriana phylicoides Briq., Draba funckeana Planch., D. Zindenii Planch., Hinterhubera columbica Sch .Bip. and Polystichum sp. Because of different floristic composition, apparently this may represent another syntaxon. Timberline forest with gnarled trees of ArcytophyUum caraaasanum (4-6 m high) with codominance of Senecio vaccinioides and Espeletiinae, was studied by T. van der Hammen & R. Jaramillo Mejia (in prep.) at 3850 m on the west slop e of th e northern part of the Paramo de Guantiva near the Laguna La Jequera. Probably this t ype of humid timberline forest with Neurolepis may pass into the Cortaderio-Araytophy ZZetum at higher altitudes. 87. Myricetum parvifoliae Vander Hammen & Cleef ass. nov. (prov.) type: T. van der Hammen & A.M. Cleef rel. 188; table 17 Physiognomy: The up to 2.5 m high microphyllous thickets have windpollinated flowers and a strongly aromatic foliage. The stand in rel. 188 is structured in: I) a shrub layer (cover 95%); 2) a rale herb layer with a cover of about 5% and up to 40 em high, and 3) a thick ground layer dominated by pleurocarpous mosses covering up to 80%. Composition & syntaxonomy: Myrica parvifolia is the principal shrub and only selective character species. This gale species is also present (locally frequent) as small tree in the upper part of the Andean forest belt and subs erial thickets. According to herbarium labels Myriaa parvifolia is common between 2650 and 3400 m in the Colombian Cordillera Oriental, in the Venezuelan Sierra Nevada de Merida, and in the Andes of northern Ecuador. Myrica parvifolia stands can be easily recognized by dominance of this Myrica species. The floristic affinity is with the shrub associations of the 8enecionetum andicolae (73) and the Hypericetum Zaricifolii (74).

171

Table 17 .

Myricetum parvi[oliae Van der Hammen & Cleef ass. nov. (prov.) author rel . & ref. nr. T. van der Hammen & A.M. Cleef ... 188 releve are a cover shrub s herbs cryptogams slope altitude m locality

50 m 95% 6% 80% 20% 3700 m Si erra Nevada del Cocuy; Salta Rio C6ncavo

cover % shr;:iblayer:

Myrica parvi[olia Rapanea dependens Senecio andicola Berberis sp. Eupatorium theaefolium Sericotheca argentea Arcytophyllum nitidum Cestrum sp. Miconia salicifolia herblayer:

groundlayer:

5 5 3

Re lbunium hypocarpium <.I Peperomia microphylla 2 Hypnum amabile 50 Leptodontium luteum IS Campylopus sp . 10

2 2

Dicranaceae Parmeliaceae

60 IS

Cladia aggregata Cladonia spp. (subg. Cenomyce)

2 I

<I 2

Orthrosanthus chimboracensis Polypodium murorum Polypodium sp. Acaena eZongata ~I Acaena cylindristachya 41 Rubus sp. 路 <I note: Symplocos theiformis, and dwarftrees and shrubs of Befaria sp. are present in the same phytocoenosis. Synecology & distribution: The association forms timberline thickets on slightly humid ground, where wat e r accumuiates from the zonal Arcytophyllum nitidum dwarfshrub paramo. The slope is about 20掳. The Myricetum parvi[oliae was only observed along the Rio C6ncavo in the Sierra Nevada del Cocuy (dry side) between 3680 and 3750 m. As discussed before in chapter II, subparamo vegetation is present here higher altitudes due to different climatic factors on either side of the Cordillera. The Myricetum parvi[oliae is scarce in the paramos of our area. Note: In pollen diagrams from clayey to peaty deposits from the last glacial period in the high plain of Bogota, local Myrica-domin a ted vege t ation is reflected, accompanied by Compositae and s.e metimes Symplocos (Van der Hammen et al. 1980). This azonal vegetation on these soils was apparently widely distributed in the high plains. The corresponding plant community may have been closely related to the Myricetum parvi[oliae. 88. Shrub of Diplostephium alveolatum Microphyllous to nanophyllous Diplostephium alveolatum is probably an Andean subspecies of Diplostephium costaricense Blake (Cuatrecasas 1969). In the study area, morphological and ecological differences can be noticed between the populations of Diplostephium alveolatum in the Sierra Nevada del Cocuy and in the paramos near Bogota. Specimens of the Cocuy population are found in Gynoxys albivestita dwarf forest

172 and in zonal subparamo thickets, together with Senecio vaccinioides , on the dry side of the Sierra up to 4060 m. The Sumapaz population of D. alveolatum (3400-4020 m) probably represents another undescribed variety , that occurs along paramo streams, and constitutes a low shrub community in the highest SWallenochloa-Espeletia bogs with Breutelia along the crestline between 3800-4000 m. Stands of these shrubs were commonly observed from the Media Naranja and La Rabona to the Cuchilla Los Charcos and Chorreras watershed areas in the central part of the Paramo de Sumapaz . Other dwarsshrub of Compositae Apart from the five already treated shrubby composite communities , the area contains a number of patches of other Compositae . The vegetation of some of these patches may deserve a separate syntaxonomical description, if more representative releves are available . The following (dwarf)shrub communities have been observed. 89 . Dwarfshrub of Diplostephium glutinosum

Diplostephium glutinosum is a nanophyllous , dark greenish rale and low dwarfshrub with white ray flowers . This species is endemic to the northern paramos of the Colombian Cordillera Oriental . Patches of Diplostephium glutinosum ssp . cocuyensis grow on exposed rocks and ridges along the wet slopes of the Cordillera from the paramos NE of Lake Tota to Pisva and to the Sierra Nevada del Cocuy (3600-4000 m) ; the ssp . glutinosum was collected in the Paramo del Almorzadero, Santurban , Romeral and Tama (39504150 m). The present distinction in two subspecies , one of which is subdivided into three formas (Cuatrecasas 1969 , 1975) , reflects the spatial isolation of these small populations on the high mountains in the northern part of the area . 90 . Dwarfshrub of Diplostephium juajibioyi Open microphyllous cinereous shrub of Diplostephium juajibioyi, 1-1 . 5 m tall, with white rayflowers and a purple disc have only been noticed on bouldery screes on the humid side of the Cordillera . Common associates are Centropogon ferrugineus , Gynoxys sp ., Acnistus quitoensis, Miconia andina, M. mesmeana var . jabonensis , M. salicifolia, Polystichum sp . , Ribes sp., Solanum bogotense, Echeveria sp . (9186), Herbertus subdentatus, Disterigma

empetrifolium, Rhacocarpus purpurascens, Chorisodontium setaceum, Jamesoniella rubricaulis, etc . The endemic dwarfshrub Niphogeton fruticosa may be present too . Diplostephium juajibioyi scree bush is only known from the northern paramos of the Colombian Cordillera Oriental , where it is present in the Paramo del Almorzadero , on the E slope of the Sierra Nevada del Cocuy (common) , in the Paramo de Pisva and on the Pe~a de Arnical, NE of Lake Tota between 3550 and 3950 m. This applies to the ssp . juajibioyi, and the community might be a separate association when more representative releves are available . From the Paramo de Sumapaz a 2-4 m high shrub was recently described by Cuatrecasas (1975) as ssp . leucopappum . This subspecies is present in Escallonia dwarfforestpockets in the open grass paramo at 3500-3550 m. 91. Dwarfshrub of Diplostephium columbianum

Diplostephium columbianum is a heather-like leptophyllous dark-greenish dwarfshrub (30-100 em high) with white to faintly lilac rayflowers . It is most common in the zonal transition from the upper bunchgrass paramo , including higher nunatak-like areas , to the lower superparamo (4000-4500 m) in the Sierra Nevada del Cocuy . In lower places Diplostephium colombianum patches

173 are found in crevices on roches rnoutonnees in the Paramo de la Rusia (37503950 rn) and in the Paramo del Alrnorzadero (3850 rn). In some places these patches are associated with open shrub of the Cortaderio-Arcytophylletum caracasanae (see 86) . 92 . Dwarfshrub of Diplostephium rupestre Fig. 29

Diplostephium rupestre is a nano- to rnicrophyllous dwarfshrub (up to 80 ern high) with cream-coloured to lilac rayflowers , hairy , green foliage, and a well-developed root system . This species is reported as new to the Colombian Cordillera Oriental , where it is presently only known from the summit area of the Nevado de Surnapaz between 4000 and 4250 rn. Diplostephi um rupestre was previously known from the high pararnos in northern Ecuador and the Colombian Cordillera Central and Occidental (Cuatrecasas 1969) . The high volcanoes of the Colombian Cordillera Central contain two other related species of the series Rupestria Blake: the widely distributed Diplostephium eriophorum Wedd . and D. ritterbushii Cuatr . , which is endemic to the Nevado de Huila. Diplostephium rupestre dwarfshrub vegetation is found on the Nevado de Sumapaz on humid clayey soil and on limestone screes (slope 10-22째) between 4100 and 4180 rn . The pH of the very dark-brown upper soil layer is 5 . 1-5 . 3. Water is regularly perculating through the calcareous gravel and soil (up to 70 ern thick) . Nect to Diplostephium rupestre which covers of 15-20%, species of the Valeriana plantaginea-Racomitrium crispulum community (27) are growing on the rocky slopes. Characteristic species for Diplostephium rupestre dwarfshrub are Bartsia sp. (8146B , reddish corolla), Poa cf . pauciflora (8094), Werneria humilis var. angustifolia, Lucilia pusilla, Bruoeruthrophyllum jamesonii (especially in wet places) , Zygodon squarrosus, Siphula sp . (8099C), Radula sonsonensis, Anastrophyllum sp . , Leptolejeunea sp. (1849), and Cheilolejeunea subg . Strepsilejeunea 1849C) . The floristic composition and the number of species (about 35) indicates a permanent and high humidity. 93. Dwarfshrub of Senecio guicanensis This yellowish to grayish nanophyllous shrub (up to 1. 5 rn high) dotted with light yellow flowering heads is endemic to the scattered superpararno vegetation of the Sierra Nevada del Cocuy between 4200 and 4500 rn . Though this species is mostly present in zonal superpararno communities on moraines , denser stands were locally observed on humid sandy ground along streams , among rocks and in slight depressions on moraines (pH 5 . 1 in rel. 324) . 94. Dwarfshrub of Senecio cacaosensis

Senecio cacaosensis is a rale grayish nanophyllous. shrub with strongly revolute leaves covered with sericeous indurnenturn and whitish flowers, endemic in subpararno Sphagnum bogs in the headwaters of Rio Casanare and the Paramo de Pisva between 3080 and 3430 rn. Common associates are Espeletia lopezii var . major, Swallenochloa tesselata, Hypericum magniflorum, Diplostephium revolutum and Puya goudotiana. 95. Dwarfshrub of Senecio guantivanus This species forms rnicrophyllous shrubs or dwarftrees in the subpararno and (subserial) in the andean forest belt between 2200 and 3500 m, mainly in the department of Boyaca. Subserial dwarfshrub of Senecio guantivanus is distributed in the arid Paramo de Guina near S. Rosa, where in many places the original shrub pararno is destroyed due to intensive grazing and burning.

174 96. Shrub of Senecio vaccinioides photo: Cleef 1978 , photo 167. Azonal patches of Senecio vaccinioides are common on humid soil in the Paramo de Guantiva between 3800 and 3900 m. These dark-greenish nanophy llous thickets with yellowish flowers are present in depressions on slopes and in "po cke ts", or locally adjacent to humid meadows with Lachemilla orbiculata , the Oritrophio- Wernerietum pygmaeae (62) and the Hyperico- Plantaginetum rigidae (65). Leptodontium wallisii is dominant in the groundlayer. Hypericum trianae or/and SWallenochloa tesselata may be associated species on the western wet side of the Paramo de Guantiva (see 81). Soils are humic, sandy to clayey, and strongl y acid (pH 4.1 in rel. 32) in the upper layer. Senecio vaccinioides shrub in the Paramo de Guantiva is geographic a lly vicariant with the Senecionetum nitidi (84) in the dry bunchgras s paramos of Cundinamarca. 97. Other dwarfshrub communities Other (dwarf)shrub species have not been found in proper communities in azonal patches. Lachemilla polylepis , .a woody species, is present up to 4450 m in the northern paramos of the Colombian Cordillera Oriental and also in the paramos of the Sierra Nevada de S. Marta, in the Venezuelan Sierra Nevada de Merida, and in Costa Rica (E;G.B. Kieft, unpubl.). This species provides a good example of the evolution of an originally herbaceous species towards a woody species, as discussed by Carlquist (1974). Lachemilla polylepis-dominated shrub is common in screes in the Sierra Nevada de S. Marta between 3800 and 4100 m (Rangel et al., in prep.). As far as known , the study area contains only solitary dwarfshrubs of Lachemilla polylepis The same applies to another ros aceous shrub, Sericotheca argentea (34004400 m), which is a common constituent of paramo thickets, mostly - on the dry side of the mountains.

Valeriana triphylla (previously V. mutisiana (Wedd.) Hoeck.) is locally found in large clumps in the paramos of our area between 3300 and 4080 m. This r are white flowering endemic shrub (30-1.50 m high) may be locally abundant on thin soils near outcrops of or on moraines. Valeriana triphylla is known from the paramos near Bogota, the Paramo de la Rusia and the Sierra Nevada del Cocuy (Arauca).

DWARFFORESTS 98. Dwarfforest of Polylepis quadrijuga Fig. 75 A phytosociological study on Polylepis quadrijuga dwarfforests in the Colombian Cordillera Oriental is in preparation by T. van der Hammen, R. Jaramillo-Mejia and the present author, and only some general information will be presented here. According to Simpson (1979) Polylepis quadrijuga is endemic to the Colombian Cordillera Oriental, and is closely related to Polylepis reticulata Hieron., P. weberbaueri Pilger and to P . lanuginosa HBK, all Ecuadorian species. Polylepis (Rosaceae, Sanguisorbeae) is endemic to the high tropical Andes, from northern Argentina and Chile to Colombia and Venezuela, between 1800 and 5200 m. Simpson (l.c.) considered PolylepiJ as the arborescent angiosperm genus with the highest natural occurrence in the world. Rosaceous parallel genera at lower altitudes in tropical Africa are Hagenia and Leucosidea . Simpson distinguished

175 15 species of Polylepis in her recent rev~s~on. The nanophyllous Polylepis quadrijuga ( syn. P. cocuyensis Cuatr., P. boyacensis Cuatr.) with compound leaves occurs from the upper forestline at 2900 m up to the lower limit of the superparamo at 4200 m (Cuatrecasas 1958). Polylepis quadrijuga dwarfforests are common on -the western Magdalena slopes of the Cordillera Oriental and rather scarce on the eastern side. Especially the western sides of the Paramo de Sumapaz, the Paramo de Guantiva and the Sierra Nevada del Cocuy contain most stands. Polylepis quadrijuga dwarfforest is present as isolated patches in the grass paramo or is found as Andean timberline forest. Terrestric and epilithic bryophytes have a cover of 70-100%. In the grass paramo isolated dwarfforests dominated by Polylepis quadrijuga were studied between 3735 and 4025 m in the paramos of Guantiva, Rusia and the Cocuy, where they grow on boulder screes or in rockshelters or on steep slopes. Height of the stunted dwarftrees is 5-10 m. Thermic conditions in the rockshelter habitats in Venezuelan paramos according to microclimatological data mentioned by Az6car & Monasterio (1979), are more favourable for the growth of arborescent species than the surrounding grass paramos. The average temperature is 2-3째 C higher and the number of days without severe frosts is considerably less than in the surrounding zonal grass paramo. rhe ecology of PoZyZepis was discussed by Walter & Medina (1969), Ellenberg (1958 a,b), and A.P. Smith (1977), and their results were summarized by Simpson (1979). Characteristic vascular species in isolated PoZyZepis quadrijuga stands in the grass paramo of the study area are: Eupatorium (Ageratinal: gZyptophZebium, Echeveria spp., Stachys cf. elliptica, LuzuZa gigantea, Senecio formosus, Cerastium sp., PoZystichum sp., OxyZobus gZanduZiferus , Gynoxys albivestita,

Galium canescens, Eupatorium (Ageratinal theaefoZium, Niphogeton ternata, Miconia andina. The austral-antarctic element is represented by the rare Dysopsis gZechomoides, an euphorbiaceous herbaceous species, found in temp erate forests in Chile and Juan Fernandez, the moss Lepyrodon tomentosus , and species of Chorisodontium. Apart from the characteristic species PoZyZepis quadrijuga stands include the following common vascular species: Mannina saZicifoZia, Gynoxys spp., OxaZis spp., Peperomia hartwegii, Miconia andina, ReZbunium hypocarpium, Sibthorpia repens , Grammitis moniZiforme, and species of Berberis and Ribes . T. van d e r Hammen and R. Jaramillo-Mejia studied timberline stand of

PoZyZepis quadrijuga in the Paramo de Chisaca (3450 m) and the Paramo de Guantiva (3350-3750 m). The PoZyZepis trees generally grow together with other codominant species of the upper Andean forest and shrub paramo, e.g.

Weinmannia fagaroides , EscalZonia myrtiZZoides, Gynoxys spp., Eupatorium (Ageratina ) tinifoZium, HesperomeZes spp., Brachyotum sp., Hypericum sp., Miconia spp. (sect. Cremanium prob.). Bucquetia gZutinosa, IZex kunthiana, which are scarce to abse nt in Polylepis-dominated patches in the grass paramo. Van derr Hammen & Gonzalez (1960a, 1963) published an inventory of a "PoZyZepietum " from the Paramo de Guantiva at 3400 m. Timberline stands may be found on flat sandy valley floors and on steep slopes. Palynological data from the Plio-Pleistocene sediments of the Sabana de Bogota and surroundings (Van der Hammen et al. 1973) suggest that PoZyZepis pollen is already present (2.5-2.7 million years ago). According to Van Geel & Vander Hammen (1973) the area of Lake Fuquene (2650 m), N of Bogota must have been covered with PoZylepis woodlands during a warmer and drier interstadial complex of the Middle Pleniglacial about 30.000 - 40.000 years B.P.

176 99. Dwarfforest of Hesperomeles cf. goudotiana Isolated stands dominated by the microphyllous rosaceous Hesperomeles cf. goudotiana were observed on the dry West side of the Sierra Nevada del Cocuy (Paramo C6ncavo) at 3800 m, and on the dry South side of the Paramo del Almorzadero from 3700 m to 3850 m. The trunks with diameters of more than I m are the thickest observed in paramo dwarfforests; the canopies reach a height of about 8 m. The stands occur in sheltered sites facing the dry interandean Chicamocha valley. This semiarid habitat with high average temperatures at these heights is favourable for arborescents. The identity 路of this species of Hesperomeles is not yet certain (H. Zanuginosa?, H. goudotiana?). Wet Hesperomeles Zanuginosa forest with Neurolepis aristata is present as zonal Andean timb er line forest at 3700-3750 m on the western Cauca slope of the old volcano ruins of S . Rosa and Otun in the Colombian Cordillera C ~ ntral (Cleef et al., in press) and in the Paramo of Barragan (Cuatrecasas 1954) . The Hesperomeletum Zanuginosae Cuatr. 1958 (syn. Hesperomeletum ferrugineae Cuatr. 1934) was described by Cuatrecasas (1934, 1958) from the upper Andean forestbelt on the Nevado de Tolima .

100. Dwarfforest of EscaZZonia myrtiZZoides table 18.

EscaZZonia myrtiZZoides is a nanophyllous dwarftree in high altitudes of the tropical Andes (Sleumer 1968). Sleumer (1968) recognized the variety myrtiZZoides (Colombia to northern Argentina) with smaller leaves and the var. patens Sleumer (Costa Rica to Venezuela and Bolivia) with larger leaves . According to Dr. H. Sleumer (L), our specimens belong to var. myrtiZZoides. In the Colombian Cordillera Oriental this taxon is found between 2650 m (Sabana de Bogota) up to 3750 m in the open paramo belt. Vander Hammen & Gonzalez (1960) reported already on an "EscaUonietum" from the Cienaga del Visitador at 3300 m in the Paramo de Guantiva . EscaZZonia myrtiZZoides is dominant, a~d Eupatorium fastigiatum is codominant; next to 17 other vascular speci es. Similar stands of EscaZZonia were also observed along paramo streams elsewhere in the Paramo de Guantiva and in the Paramo de la Rusia at 3550 m, together with 3-4 m high shrubs of Hypericum Zaricifolium ssp. Zaricoides. Boggy stands with EscaZZonia myrtiZZoides are known in mires surrounding the Laguna la Guitarra at 3425 m, some km W of the Nevado de Sumapaz (Meta). Vareschi (1958) reported an EscaZZonia tortuosa HBK (= E. myrtiZZoides) dwarfforest on the marshy shores of the Laguna Coromoto at 3400 m in the Venezuelan Sierra Nevada de Merida, where Dryopteris paZeacea Christ. and Sibthorpia repens are abundant in the understorey. Timberline dwarfforest with dominance of E. myrtiUoides was studied by T. van der Hammen & R. Jaramillo-Mejia in the headwaters of Rio S. Rosa at 3450 m in the Paramo de Chisaca, the northernmost part of the Paramo de Sumapaz. A phytosociological treatment of this type of EscaZZonia dwarfforest is in preparation . EscaZZonia myrtiZZoides stands on the cloud forest timberline have been observed elsewhere in the Paramo de Sumapaz, e.g. in the Rio Nevado valley and its tributaries (Meta) between 3300 and 3550 m. Eupatorium (Ageratina) tinifoZium is a common associate, just as l路Hconia saZicifoZia, Gaultheria ramosissima, Mannina salicifolia, Chusquea scandens, Gynoxys sp., Berberis cretata, Oreopanax mutisii, Centropogon ferrugineus and Espeletia tapirophila. An inventory follows of an EscaZZonia myrtiZZoides-dominated pocket surrounded by open bunchgrass - bamboo paramo at 3535 m above the SE shore of the Laguna El Nevado on the WSW slope of the Nevado de Sumapaz, surveyed in January 1973. Its floristics mainly reflect the vicinity of the wet timberline.

177

Table 18

EscaUonia myrtilloides "pocket, 3535 m (Nevada de Sumapaz, Meta). ~~~~L~E~£i:~~:

Escallonia myrtilloides Miconia latifolia Senecio andicola Diplostephium juajibioyi ssp. leucopappum Miconia cleefii Senecio fZos - fragrans Diplostephium sp. Senecio vaccinioides Senecio guadelupe

Berberis cf . sumapazana Eupatorium tinifolium Oreopanax mutisii Gaultheria ramosissima Cestrum parvifolia Acnistus quitoensis Gynoxys sp. DipZostephium cf. alveolatum

~~E£~£~~~~-~E~£i:~~:

CaZceolaria penlandii Peperomia · sp. (8018) Peperomia sp. SWallenochZoa tesseZata Rhynchospora sp. Pteridium aquilinum

Grammitis spp . Hydrocotyle sp. Rumex tolimensis Greigia sp. lianas:

Valeriana pavonii

£E~~E~~!~~ (epiphytic):

Herbertus subdentatus (large form) Bartramia angustifolia Syzygiella sp. (8021) Porotrichodendron robustum Chorisodontium setaceum (terrestric): Dicranaceae (8029) Trichocolea sp. (8025)

Zygodon goudotii Acrocarpous moss ( 8029)

Metzgeria decipiens Lejeuneaceae (8030) (epiphy tic lichen)

Sphaerophorus meZanocarpus

Atracty locarpus longisetus Other Escallonia myrtiZloides stands at the wet c l oudforestline were also observed in the headwaters of Rio Casanare (Alto El Paleo, Quebrada Lo s Osos, Q. El Play6n) between 2750 and 3100 m. An open $scallonia myrtilloides-dominated dwarffores t was observed a t 3750 m ~n th~ plain at the base of Paramo C6ncavo on the dry W ·side of the Sierra Nevada del Cocuy. In the Colombian Cordi l lera Central EscalZonia myrtilloides dwarffores t was recently studied in the Parque Los Nevados (Cleef e t al., in press). Around Lake Otun Escallonia myrtilloides shrub and dwarfforest is present be tween 3900 and 400~ m. In well-developed stands Escallonia myrtiZZoides is the only dominant dw~f ftree species. Dominant species in the groundlayer ar e Geranium sibbaZdioides, Leptodontium sp. Zygodon pichinchensis and Agrostis cf. haenkeana. Sleumer ( 1968) reported pure stands of Escallonia myrtilloides from the Ecuadorian Cordillera Occidental near Riobamba. 101. Dwarfforest of Gaultheria ramosissima and Aragoa perez- arbelaeziana This t ype of ericaceous dwarfforest with Aragoa perez - arbelaeziana and Compositae shrubs was only seen and studied in the Chorreras valley on the W side of the Paramo de Sumapaz. A stand was found in a po cket at 3750 m on a steep, rocky slope surrounded by open Calamagrostis effusa - Oreobolus obtusangulus ssp. rubrovaginatus bunchgrass paramo, and facing NW towards the vi llage of S. Juan .

178 The blackish clayey soil (pH 4.4) between the boulders was not thicker than IS ern. A 10 ern thi ck felty, brownish Aoo layer was overgrown by bryophytes . Rel. 30S (see table 19) represents record of this stand. Other common species in this dwarffore st , but not recorded here, are Gynoxys sp. (grayish leaved species, also present in rockshelters near the Laguna Gobernador; see table 20), Miconia salicifolia and Tristerix sp. Table 19

Gaultheria ramosissima - Aragoa perez- arbelaeziana dwarfforest. rel. nr . 30S exp. NW slope (degree) 25째 sample plot area 100 rn2 cover trees 65 % (height up to 6 rn) II II cover shrub 50 % ( II S rn) II II II ( cover dwarf shrub 22% I . S rn) cover herbs 30% ( II 30-100 ern) cover bryophytes 100% (I 0-30 ern) alt. 3780 rn lo ca lity Paramo de Sumapaz, Al to de Chorreras

~~~~~-~ - ~~~~E!~~~ - 1~Y~~ 40 Gaultheria ramosissima IS Aragoa perez- arbelaeziana

S Diplostephium heterophyllum S Rapanea dependens ~~~~~-~-~~~~~-1~Y~~ 10 Gaultheria ramosissima 10 Aragoa perez-arbelaeziana IS Diplostephium heterophyllum 10 Berberis goudotii 3 Hesperomeles pernettyoides 2 Eupatorium (AgeratinaJ glyptophlebium ~~~~~-~ - ~~~~E~~~~~ - 1~Y~~ 10 Vaccinium floribundum var. marginatum Vaccinium floribundum var. floribundum 1 Hypericum caracasanae ssp. car donae S S

Disterigma empetri folium Senecio guadelupe Blechnum sp. (subg. Lomar ia ) Rubus sp.

~~~~~-~-~~Y~E~Y!~~

Plagiochila sp. (8377) Jamesoniella c f . undata (8369) Herbertus subdentatus (large form) Atractylocarpus sp . (8384) I Dicranum frigidum 5 Sphagnum magellanicum ~I Riccardia sp. (8381)

40 3S IS 2

I Jungermanniales (8371) <I II (8382) <I II (8383) I Plagiochila sp. (837S) < I Lepidozia sp. (8376, 8378) I

Radula ramu lina Metzgeria sp. (837 1)

<I p l eurocarous moss (8373) <I Bartramia angustifolia <I Pleurozium schreberi 41

Chorisodontium sp .

cover % l ichens

-----T- sphaerophorus melanocarpus

~~~~~-~-~~~~-!~Y~E 10 Hydrocotyle gunnerifolia IS Elaphoglossum aff. engelii (83S9) 2 Elaphogloss;;.m sp. ( 8362) I Hymenophyllum sp. (8361) 2 Oxalis medicaginea I Nertera depres.sa I Luzula gigantea I Gramineae (Calamagrostis sp.?)

2 Cortader ia sp. ~I

Relbunum hypocarpium

<I Cerastium sp. The stand is extremely rich in epiphytes , main ly Usnea sp . (8386), Frullania sp. (8394), Parmeliaceae and mosses. Erect and pendulous po l ypodiaceous ferns (e.g.

Polypodium angustifolium, Grammitis flabelliformis, G. variabilis, G. meridensis)

179 are conspicuous among the vascular epiphytes. A thick mat of liverworts cove rs the litter on the ground completely. This indicat es wet atmospherical condit ioas , mainly caused by fog from the timberline condensation zone. Aragoa perez - arbelaeziana dominates in more op en dwarfforest. Berberis goudotii, Sphagnum magellaniaum , and Jamesoniella rubriaaulis attain a highe r cover t han in the shady stands dominated by Gaultheria ramosissima . The c over of the ski ophy tic Plagioahila sp . (8377) is strongly reduced under Aragoa dwarftrees and shrubs. The leptophyllous to bryophyllous dwarftrees of Ar agoa per ez- arbelaeziana a re S-9 m high and have pale yellow flowers. This species is the only tree sp ec i e s in the genus (Romero 1972, Mennega 1974). The paramo genus Aragoa appa rently has it s main centre in the southern paramos of the Colombian Cqrdillera Oriental. Observation: The stand provides shelter to numerous raccoons (Nasuella olivaaea) .

102. Dwa rffor e st of Gynoxys albivestita

Gynoxys albivestita dwarffore st are f ound in the Sierra Nevada del Cocuy between 3900 and 4000 m in the hi gh valley of Lagunillas . The se gray ish microphyllous Compositae trees are S-8 m high and predominant on ro cky slop e s. Diplostephium alveolatum, Seneaio vaaainioides, Solanum bogotense and Ser iaotheaa ar gentea are associated species. Gynoxys al bivestit a dwarfforest is also found on the opposite humid side of the Si erra Nevada del Cocuy between 3400 and 4250 m. Valeriana arbor ea is an associated species above the 4000 m level. It occurs commonly between boulders a t 4100 m from the Paso de Rancheria to the Alto de Cusiri . Characteristic in bamboo paramo stands in the Sierra Nevada del Cocuy are Aanis tus quitoensis , Miaonia andina, Vaaainium flor ibundum, Miaonia saliaifolia, Centr opogon fe r rugineus, Ribes sp. (9188), Eaheveria sp. (91 86) and in the lowe r a reas a lso Miaonia mesmeana var. j abonensis. Gynoxys albivestita is common i n Polylepis quadrijuga dwarfforest in\ our are a, e.g. in the Paramo de la Rusia and in the high valley of Lagunillas~ Sierra Nevada del Cocuy (3700-4000 m). Gynoxy s albivestita is endemic to the paramos of Boyaca, Arauca and Santander.

103. Other dwarfforests of Gynoxys A number of other Gynoxys species were described from the Colombian Cordillera Oriental, but a systematic treatment of this genus is not yet ava ilable. Gynoxys occurs in isolated more or less pure dwar fforest stands in open paramo. Sometimes even two species may dominate. It also is an constituent of the upper Andean forest together with other species. At present about 10 species of Gynoxys can be recognized in the Colombian Cordillera Oriental. Some of these 1~ orm communities in their own ri ght, e. g. Gynoxys hir suta, G. par amuna,

suba~nerea,

G. subhir suta, G. trianae .

Gynoxys-dominated dwarfforests were studied by Van der Hammen & Jaramillo M. (in prep.) on the Alto de Oseta in the paramo E of Mongui near Lake Tota. There, at 3715 m, the composite dwarfforest consists of two species of Gynoxys (one species dominant) associated with Ager atina sp. (Jaramillo-Mejia 4055) and Miaonia saliaifo l ia . About IS km SE of this locality, a Gynoxys-Aanisius dwarfforest pocket has been observed at 3400 m in bamboo paramo at the base of the Pena de Arnical. Associated species are Hesper omeles sp., Eupatorium (Ageratina) tinifolium, Diplost ephium sahultzii, Berberis s p., Miaonia cf. ligustrina, Purpur e lla g r ossa , Rapanea dependens, Hypericum sp., Symp loaos sp., Seneaio vaaainioi de s, a solitary Weinmannia sp. (8 m), SWallenoahloa t esselata, Caryophyllaceae (9490), Nertera granadensis (dominant), Moritzia lindenii, Peper omia sp. and bryophy tes as .CamPylopus ahr ismar ii var. suboblongus, C. t r iahophorus, Catagonium politum, Or eoweisia cf . laxir etis, Prionodon

180

fusco-lutescens, Porotrichodendrum superbum, Syzygiella sp. In bamboo paramos near Bogota, some dwarfforests stands with Gynoxys have been sampled. Here Acnistus quitoensis was subdominant, and associated with Gynoxys dwarfforest in the lower part of the bamboo paramos, especially on the eastern side of the Cordillera. A pocket with Acnistus-Gynoxys dwarfforest surrounded by bamboo paramo was found in the Chuza valley E of Bogota at 3550 m (rel . 403) . Up to 10 m high trees of Gynoxys sp. loaden with epiphytes are dominant and Acnistus quitoensis is subdominant. The herbaceous layer is dominated by Drymaria villosa ssp . paramorum and Salvia killipiana and has a cover of about 100%. Terrestric bryophyte cover about 90% ; Plagiochila sp . (9626) and Metzgeria sp. (9634) are prominent. Between 3600 and 3750 m, in the headwaters of the same valley, and farther north to the Paramo de Palacio small patches of a Gynoxys species with grayish leaves are common . Sibthorpia repens, Moritzia lindenii and Thuidium peruvianum are present in the groundlayer . At 3850 m in the Paramo de Chisaca, a rale Gynoxys subhirsuta dwarfforest is present on boulders at the base of a steep wet cliff on the southern shore of the glacial lake Laguna Negra . Associated species are Cestrum parvifolium, Hesperomeles cf . pernettyoides, Myrrhidendron glaucescens and Hydrocotyle hederaceae Boggy ground between the boulders contains hummocks of Sphagnum magellanicum and S. oxyphyllum. Other cryptogams characteristic for wet conditions are Leptodontium wallisii, Chorisodontium mittenii, Campylopus cavifolius, Anastrophyllum leucostomum and Sphaerophorus melanocarpus. Another inventory (table 20) was made 30-35 km SSW from this locality in Gynoxys dwarfforest on the W slope of the Paramo de Sumapaz. There, in a rockshelter at 3885 m near the Laguna Gobernador also a Gynoxys species was dominant, probably also G. subhirsuta. Table 20

Gynoxys dwarfforest near the Laguna Gobernador (3885 m), Paramo de Sumapaz dwarf trees and shrubs: Gynoxys sp. (dominant)

Miconia salicifolia Hypericum laricifolium ssp. laricifolium Diplostephium cÂŁ. heterophyllum Hesperomeles sp. Berberis sp. Cestrum parvifolium Diplostephium sp. (8332) Ugni myricoides

bryophytes:

Sphagnum magellanicum Campylopus gertrudis Atractylocarpus longisetus Chorisodontium speciosum Dicranum frigidum Omphalanthus filiformis Jamesoniella rubricaulis Leptoscyphus porphyrius

herbacous species :

Swallenochloa tesselata Myrrhidendron glaucescens Hydrocotyle sp. Rumex to limensis Elaphoglossum spp . Grammitis moniliformis Hymenophyllum karstenianum

104. Senecionetum flos-fragrantis ass. nov . (prov.) type : rel . 467; table 21 Physiognomy: This dark-green, nanophyllous dwarfforest, consists of 3 layers: I) an upper stratum of gnarled Senecio flos-fragrans dwarf trees, up to 2 . 30 m high with a cover of 75%;

181 2) a rale open herbaceous fieldlayer , about 30 em high, with a cover of about 12%, and 3) a groundlayer, with a cover of 80% , and consisting of a nearly closed mat of vascular plants with prostrate stems (LachemiZZa tanacetifolia, Geranium sibbaldioides, LachemiZZa holosericea), cushion-like herbs (Cerastium sp ., Montia meridensis) and bryophytes . Composition & syntaxonomy : Gnarled dwarf trees of Senecio flos-fra gans var . frigidophilus are characteristic . Senecio formosus , Montia meridensis, LachemiZZa tanacetifolia, Jamesonia goudotii and Lycopodium crassum are superparamo taxa and reflect the high location of the stands . The relatively low number of species is also an indication (17 in rel . 467) . Table 21

Senecionetum flos-fragrantis ass . nov . (prov . ) ... 467 5160 m Sierra Nevada del Cocuy Patio Bolos , S. Luis (Arauca) releve area 24 m2 soil sandy rel . nr . alt . lac .

dwarf tree layer:

Senecio flos-fragrans var . frigidophilus

cover % 75

fieldlayer :

Senecio formosus Lorenzochloa erectifolia Jamesonia goudotii Lycopodium crassum

groundlayer :

LachemiZZa tanacetifolia

Cerastium subspicatum (cushions) 5 Geranium sibbaldioides 2 Lachemilla holosericea Montia meridensis < 1+ Calandrinia acaulis 1 Breutelia sp. 15 Leptodontium sp . 15 Campylopus pittieri 5 Peltigera sp . 1 Cora pavonia 3 Tayloria sp . 2

Floristically the greatestaffinity is shown to high altitude thickets and dwarf forests of Senecio vaccinioides and Diplostephium rhomboidale fringing the grassparamo-super paramo moraines between 4300 and 4400 m in the Paramo C6ncavo at the western side of the Sierra Nevada del Cocuy . Synecology : The dwarfforest is found on brown , humic , sandy probably fluvio-glacial deposits in protected sites at the grassparamo-superparamo transition . Patches of similar composition can be noticed on decayed soligenous Distichia bogs in the lower superparamo . Distribution : This type of dwarfforest was oniy observed at 4160 m near Patio Bolos , south of the Laguna La Plaza on the eastern slope of the Sierra Nevada del Cocuy (dept . of Arauca) . Some patches may be present in the lower superparamo in this area (4300 m). Note : Senecio flos-fragrans var . frigidophilus has been collected in bogs in the upper subparamo and the lower superparamo between 3770 and 4525 m in the Cocuy area . The var . flos-fragrans occurs as a low shrub (0.5-2 m) in the southern paramos of the Cordillera Oriental (Cruz Verde to Sumapaz) on humid soils and in bogs between 3300 and 4000 m. The shrub Senecio ramentosus (= S . flos-fragrans var . ramentosus in the author's opinion is characteristic in the northern part (Almorzadero to Santurban and Tama) of the Cor dillera Oriental .

182 105 . Dwarfforest of Diplostephium rhomboidale This grayish nanophyllous Composit ae dwarfforest is distributed in patches in the dry upp er bunchgra ss paramo on the dry side of the Sierra Nevade de l Cocuy between 4100 and 4400 m, where it is restricted to boulders in protected areas. Poa cf. paucifZora is abundant in these patches at 4350 m on the C6ncavo Boca toma divide. An incomplete survey of an open Diplostephium rhomboidale stand on the southern shore of the Distichia lake (of community 64) at 4100 min the Bo catoma valley is given below (table 22) . The stunted Diplostephium rhomboidale trees are about 3.5 m high . Table 22

Diplostephium rhomboidale dwarfforest rel. nr . slope sample area cover dvmrftrees dwarf shrub herbs b ryophytes lichens boulders alt. locality

335A

shrubs

400 45 % 10% 60% 7% 3% 60% 4110 m Bocatoma valley, Sierra Nevada d e l Cocuy (Boyaca)

cover % dwarftrees & shrubs: 40 Diplostephium rhomboidale

Diplostephium lacunosum Valeriana arborea 3 Senecio vaccinioides Eupatorium (Ageratina) gl yptophlebium dwar fshr ubs & herbs I Hypericum caracasanum ssp . cardonae 10 Pernettya prostrata <I Miconia chionophila 60 Calamagrostis effusa < I Jamesonia bogotensis 2 Castilleja s p . <I I

Peperomia sp. Cerastium sp. <I Senecio cf. formosoides (8767) <I <I

terr e stric bryophytes I

Breutelia

<I Herbertus subdentatus 5 Campylopus pittieri I Brachythecium cf. pseudorutabulum

<I Hypnum mirabile <.I PeUigera sp. 3 Cladonia coccifera epiphy tes

Usnea sp., Peperomia hartwegii

Diplostephium rhomboidale is generally asso ciat e d with Senecio vaccinioides in

the Si e rra Nevada del Co cuy : I) at the lower border of the superparamo up to 4400 m (see 22), and 2) in subparamo thickets, together with D. alveolatum, in lower loca tions up to the And ean fore s t line. Acco rding to Cu a trecas as (1969) and our own observations, Diplostephium rhomboidale occurs in the Sierra Nevada d e l Cocuy, on the dry side of this mountain chain, between 3800 and 4400 m. Its r are var. pauciflora Cuatr. has been collected in paramos near Bogota (3450-3700 m) and in northern Ecuadro (3500-4000 m) . No te : Diplostephium lacunosum is a rare endemic shrub which was found b y the author only in the Bo ca toma valley (4050-4100) , in the Sierra Nevada del Cocuy, where it grows in local small grove s on moraines, often a ssociated with scattered dwar ftrees of Valeriana arborea and Gynoxys albivestita.

183

DRY AND HUMID MEADOWS Various types of azonal meadows are present in the study area . They are subdivided int o short grass meadows and low rosaceous herbfields . The grassy meadows are dominat ed by Gramineae of low stature , e . g . cushion- like grasses (Aciachne ~ Muhlenbergia) and t ufts or sma l l tussocks (resp . Agrostis foliata and Lorenzochloa erectifolia). Low grasses are also present in the rosaceous herbfields , which are mainl y made up of acaulescent rosette species of Acaena or Lachemilla (both Sanguisorbeae) . 106 . Lorenzochloetum erectifoliae ass . nov . t ype : rel . 187; table 23; F ig . 76.

Table 23 .

Lorenzochloetum erectifoliae ass . nov .

rel . nr . slope (degree) re l eve area m2 cover vegetation % soil pH topsoil soil depth em appro~imate number of species al t . m l ocality : Paramos near Neusa

d d

cover % -------c & d and other taxa Lorenzochloetum erectifoliae Lorenzochloa erectifolia Senecio nitidus Polytrichum juniperinum Cladia aggregata Cladonia isabellina Arcytophyllum muticum Valeriana longifolia Cladonia cf . squamosa Cladonia subg . Cenomyce Geranium sibbaldioides LachemiUa spp . Acaena cylindristachya Satureja nubigena Es peletia argentea Cora pavonia Lycopodium spurium Orthrosanthus chimboracensis cf . Erythrodontium sp. Diploschistes sp. Cladonia capitata BreuteUa s p . Hypericum mexicanum PeUigera sp. Campylopus suboblongus Lepidozia s p(p). (4 171 , 61 02) Cladonia hypoxanthoides Isopterygium sp . ( 4164 , 6 106) Paspa lum bonp landianum.

S14 4 12 100 c;s

S 1S

1S 3620 LS

21 3SSO LS

s 20 100 c

100 8 16 100 c 4.6 110 32 3620 N

187 10 16 100 c 4.7 100 20 3640 LS

...

3 1

7S (1 <1 <1

( 1...

<It

{ 1+

< 1-t-

<J '-1

<h <I +

9S <1

( I+

<1+

<J + 2

.( j

o(. j

s 2

<. 1 10 I

<I+ 3 <I

.(!

<I <.I

<I IS

184

Paepalanthus karstenii va r . corei Poa c f . pauciflora Calamagrostis effusa Campylopus sp. (4163) Senecio fo rmosus Laestadia muscicola Carex sp . (4156) Miconia chionophila Calamagr ostis bogotensis Espeletia barclayama Agrostis breviculmis Potti acea e (41 69 ) or Mielichoferia? Leptodontium pungens Bledhnum loxense Rumex acetosella Leptodontium c f . lut eum Ophioglossum crotalophoroides Werneria granadensis Marchantia berter oana Si bthorpia r epens Hypericum thuyoides Cladonia bacillaris C. c f . fimbriata Locality:

LS N

10 3 3 3 4 11' .( 1 -t

<.I <.I <I <I <I <I <I <. I 15

<I <I <Iâ&#x20AC;˘ I <I <I+

Lag una Se c a Neusa, Te l ecomuni caci6n

Phy siognomy : The Lorenzochloetum is an almost closed dry t o sli ghtly humid bunchgra s s vegetation . The bunch gras s layer is most conspicuous and has a cover of 75-100 %. The cove r of the bryophyte l ayer is 3-25 %, and this lay er is domina t e d by acrocarp ou s moss e s . Compositi on & syntaxonomy : Lorenzochloa erec tifolia is a s e lective charact e rspecie s . Other cha ra c terspecies are absent. Lorenzochloa is a monotypic tropandean tuss ock grass closely related to the monotypic Aciachne. Both belong to the tribe Stipeae, and are a lso reported for Costa Rican paramos (Pohl 1980) . As othe r t axa in the s ame tribe , Lorenzochloa erectifolia stands out by a number of xeromorphic f ea tures. This specie s was found between 3500 and 4350 m in the paramos of the Colombian Cordillera Or iental. Other common species are juvenile shrubs of Senecio nitidus, and Arcytophyllum muticum, Espe l e t ia argentea,

Acaena cylin4ristachya, Polytr ichum juniper inum, Campylopus argyrocaulon (or C. cf . suboblongus ), Cl adia aggr egata and Cladonia isabellina . The association is rich in species of Cladonia subg . Cenomyce. The numbe r of spe c ies is about 20 (15-32 i n 4 rel eves) . This association has affinities with the zonal Espeletia argentea- Calamagrostis effusa lower bunchgrass paramo (17). Though Lor enzochloa erectifolia cle a rl y finds i ts optimum in the pr esent community , it is a sp e cies with a wide ecolog ica l range , and has a lso been found: I) locally with Espeletiinae a long the upper bunch grass line (4250-4350 m) in the Sierra Nevada del Cocuy and Paramo de Guantiva (see 20) ; 2) adj a cent to the Aciachnetum pulvinatae ( 3850-3900 m) , together with -Senecio canescens; and 3) loca lly on terr a ce sediments along paramo streams and a ssociated with Carex pichinchensis and Po lytrichum commune at c . 3600 m (see 50) . Synec ology: This bunch grass assoc iation is distributed in patches i n the lower bunchgr a ss paramo with zonal Espeletia - Calamagrosti s effusa swale . As a rule the Lor enzochloe t um is found on concave slopes (4-10Â°) , where the wate r is collecte d from the zonal Calamagrostis effusa paramo with Espele t i a argentea or E. barclayana. At the base of the Lorenzochloetum the zonal humid shrub of

185 the Senecionetum nitidi may be found and also boggy sloping valley floor communities. In dense stands an Aoo-layer (up to 3 em thick) may be found in the dense shadow of the tussocks. The upper black clayey layer is about 70 em thick. Below this layer to about 100 em follows a dark gray or yellowish brown, sandy clayey layer . The topsoil layer is moderately acid (pH 4 . 6-4.7) ; in rel. 187, at a depth of I m and near the sandstone bedro ck , the pH was 5.1 . Distribution: The Lor enzochloetum is only known from the dry lower buchgrass paramos between Neusa and S. Cayetano (60 km north of Bogota) between 3550 and 3650 m. 107. Aciachnetum pulvinatae Vareschi 195 3 em . Cleef type : rel. 328; table 24; Fig . 27 (also Smith 1972, fig. 4). lit.: Vareschi 1953, 1970; Smith 1972, Cleef 1978. In the last publication, reference is made to other authors dealing with Aciachne pulvinata growth, and additional data a re provided on composition, ecology and distribution. photo: Cleef 1978, photo 179; Vareschi 1953 , fig. 8; Vareschi 1970, fig. 4c & b; Smith 1972 , fig . 2b, fi g . 3 . Physiognomy : The Aciachnetum forms low prickly cushion grass meadow.s. The grass hummocks are 10-25 em high and ring-shaped due to decay of the older parts of the grass. Table 24.

Aciaohnetum pulvinatae Vareschi 1953 em. Cleef

rel. nr. slope (de gree~ rel eve area m cover % vegeta tion soil pH topsoil soil depth em approximate number of species alt. m. lo cality

31 10 2 100

c 3.9 70 10 3845 Gua

!56 328 336 452:x 567% PRESENCE TABLE ,...... ,...... I 12 5 3 5 u 2 12 .....C'CI 15 16 9 !-< <U 0 ::;l ..... 90 85 95 90 95 N C'CI C'CI C'CI c Cs c Sc <U'O s <U !-< !-< <U ..., !-< !-< 1:1 4.6 5. 2 5.0 C'CI 0 <U ..... 1:1 u C'CI:> ..... <U ..... u 20 ? 35 ? 35 :>. '-" ..... "''-" 16 15 7 18 8 !-< !-< ...,::;l \<U 0 C/) ;:;:: 3985 4045 3955 3735 3885 u Coc Coc Coc Coc Alm (6) (3) (3)

cover %

~-& -rand

.A.

other taxa Aciachnetum

c Aciachne pulvinata c Aciachne pulvinata T c Acaulimalva purdiei

pulvinatae

98 <I <I

~]+ Calandrinia aoaulis <I Geranium sibbaZdioides ~I Rumex acetoselZa Agrostis brevicuZmis Hypericum caracasanum ssp. car donae LachemiZla pinnata Acaena cyZindristachya Arenaria sp. Agrostis trichodes Sisyrinohium trinerve PoZytrichum juniperinum CZadia aggregata Carex sp . (C. peucophi Za?) Cerastium sp. <I+ Leptodontium pungens Oreomyrrhis andiooZa LachemiZla orbiculata

90 5 2 I <I

85 15 <I <I+ <I+ <.] + 3 I <. I <I <I <I+ <I <I+

95 5 <I <I

85 10

I+ I .(I+ <I+ <I+ <.I 3 I+ .C::]+

80 10 I I+ I

<I+

< I+ I <.I <.1+

<I+ ? <I+ <I+

-<I+

X X

2 ~I

X X X X

X X

186

Hypochoeris cf. sessiLifLora

< 1+

and 12 infrequent species main d/o taxa Sierra Nevade de Merida

Niphogeton dissectum ThamnoLia vermicuLaris Leptodontium fLexifoLium LobeLia sp.

X X X X

main d/o taxa Nevada S. Isabel, Cord . Central

Eryngium humiLe Satureja nubigena Agrostis haenkeana CaLamagrostis Hypericum Lancioides Lupinus cf. humifusus Bromus Lanatus Senecio repens GentianeLLa dasyantha +) number of releves:

X X X X X X X X X

( )

Composition & syntaxonomy: Dominant and exclusive character species is Aciachne puLvinata, a small xerophytic cushion grass. It is closely related to LorenzochLoa erectifoLia. AcauLimaLva purdiei and CaLandrinia acauLis are preferential characterspecies . Their sessile rosettes are opulent in patches of gravel in the atmospherically humid lowermost superpararno (see 25), and they are also present in Venezuelan stands of this association. Other frequent species in the study area are Geranium sibbaLdioides, Rumex acetoseLLa, Hypericum caracasanum ssp . cardonae, Agrostis brevicuLmis, LachemiZLa pinnata, Acaena cyLindristachya and Leptodontium pungens . Cetraria arenaria and C. isLandica ssp. crispiformis are common in cattle-free areas on top of the cushions of Aciachne. ThamnoLia vermicuLaris is common in the Venezuelan meadows; Cetraria spp. in the meadows of the Colombian Cordillera Oriental . In the Aciachnetum puLvinatae, in the Parque Los Nevados in the Colombian Cordillera Central, the following taxa are absent: AcauLimaLva, Agrostis brevicuLmis, Hypericum caracasanum, LachemiLZa pinnata and Acaena cyLindristachya . Common species . are here Eryngium humiLe, Satureja nubigena, Oreomyrrhis andicoLa, Agrostis sp., LachemiLLa orbicuLata, Hypericum Lancioides and Lupinus cf . humifusus (Cleef et al ., in press) . The Aciachnetum has strong floristic affinities to the Acaeno~PLantaginetum sericeae (see 18) as well as to the AcauZimaLva-Agrostis brevicuLmis lower superparamo vegetation on stable, gravelly slopes (see 25). Aciachne-dominated meadows seernto develop zonally in some places of the Peruvian puna, where according to Hitchcock (quoted by Chase 1924) Aciachne is "the dominant or even the only grass on whole hills". There might be a number of regional associations dominated by this rnonotypic genus throughout the tropical Andes, which Inay be combined into an Aciachnion puLvinatae (prov.). Synecology: The Aciachnetum is found in all kinds of dry depressions , on dry valley floors, on gently sloping (up to 12째) dry ground, and on sandfilled former lakelets. Soils are clayey or sandy, and depending on bedrock and altitude, black to dark and light gray . Thickness is 20-70 ern . The pH of the toplayer is strongly to moderately acid (3.9-5.2). According to Smith (1972) Aciachne puLvinata retains the moisture from fog, the direction of which it originates, reflects the direction of growth . In slightly more humid flat ground the Aciachnetum is replaced by the Agrostio-LachemiLLetum orbicuLatae ( 1 1 1) . The Aciachnetum is grazed by horses and sheep. The manured soil carries Rumex

187

acetosella, Lachemilla orbiculata, Agrostis trichodes and Paspalum bonplandianum. Distribution : Dry meadows with Aciachne pulvinata occur throughout the high tropical Andes from the puna of NW Argentina to the Colombian and Venezuelan paramos . In the study area the Aciachne路tum pulvina"ta is present in the dry paramos of the northern part of the Cordillera Or iental (Boyaca, Santander) between 3700 and 4100 m. The association wa s also studied in the Vene zuelan Sierra Nevada de Merida between 3800 and 4150 m (Vareschi 1953 , Smith 1972 , .C leef , unpubl.) and in the Parque Los Nevados (3800-3900 m) in the Colombian Cordillera Central (Cleef et al., in press). Other communities with Aciachne pulvinata : In areas between the Aciachnetum pulvinatum and the surrounding zonal and azonal vegetation some other azonal c on~unities occur, the most common of which is equally dominated by an Aciachne pulvinata - Agrostis breviculmis - Lachemilla pinnata meadow (pH topsoil 5.5). Where about one third of the Aciachne hummocks have died, Niphogeton josei appears locally. Rosettes of Plantago sericea ssp. argyrophyUa and the rare Phyllactis rigida may found together with Aciachne on bare sandy slopes . 108. Muhlenbergietum fastigiatae ass. nov. type : rel . 106 ; table 25; fig. 27 (also fig . 75). Physiognomy : The asso c iation forms graminoid, low hummo cky , humid and wet meadows. Mosses , low herbs and sedges are often associated or may be codominant. If a moss layer is present, it is up to 8 em thick and may have a cover of 80% . Muhlenbergia and mosses are intermingled. The graminoid layer with its characteristic bluish hue is about 20 em thick and as a result of its ramifications it forms a dense cushion-like grass carpet. Table 25.

Muhlenbergietum fastigiatae ass . nov.

rel. nr. slope (degree ) releve area m2 cover % grasses mosses pH top soil number of species (approx . ) alt. m locality cover % c sp:-~hZenber~ietum [asti~iatae c Muhlenbergia fastigiata o t;.her taxa

B)eutelia chrysea teptodontium luteum Carex pichinchensis Breutelia allionii Sphagnum cuspidatum Agrostis sp. Juncus cyperoides Carex cf. peucophila Werneria pygmaea Galium trianae Montia fontana cf. Drepanocladus Calliergone lla cuspidata Geranium confertum Campylopus cf. cavifolius

106 I I 60 80 5.8 II 3535 Pi

257B

160 I 4 60

I 70 10

491 5 4 95 7

566 I 6 40 60

4 3610 Pi

6 38 70 Coc

3 3850 Alm

4 3775 Rus

5.8 8 4060 Coc

80 <I+

...

415A

I 35 72

2 I 60

70 I 10 5 5 50 <:.1+ 2 5 5

"'I I

188 (566) Jungermanniales

Gentianella corymbosa Pleurozium schreberi Agrostis breviculmis Carex bonplandii Callitriche sp . Eleocharis stenocarpa localiti es: Pi Coc Alm Rus

Paramo Sierra Paramo Paramo

(257b) ( 160)

I <I

20 -<:J

de Pisva Nevada del Cocuy: Alto Valle Lagunillas del Almorzadero: El Tutal de la Rusia: Pena Blanca

Composition & syntaxonomy: This association is dominated by the selective character species Muhlenbergia fastigia ta. Like the grasses in the previously described associations , this tiny hummocky grass species with involute green-bluish blades belongs to the tribe Stipeae, and is widely distributed in the tropical Andes from northern Argentina and Chile to Colombia . In the subparamos and grass paramos of the study area Muhlenber gia fastigiata is the most common species in such meadows, but according to herbarium data Muhlenbergia ligularis and M. linearis may be present also . Common associated ~pecies are Breutelia chrysea, B. allionii, Sphagnum cf. cuspidatum and Carex

pichinchensis. A number of occasional charact er and companion species of the OritrophioWernerietalia and the Marchantio-Epilobietalia (especially the Calamagrostion ligulatae ) indicate that syntax onomically the association might occupy an intermediate position between these orders. The number of species and the composition largely depends on altitude and neighbouring communities . Mosses are common in peaty paramo stands of the Muhlenbergietum fastigiatae, but they seem absent in the communities described by Ruthsatz (1977) and Cabrera (1958) from the Argentinan puna, which are distinctly different from the described paramo association. Synecology: The azonal graminoid cushion meadows of the Muhlenbergietum are characteristic and common on damp soil in the transitional zone between wet azonalcommunities and zonal paramo vegetation . This is an edaphically controlled association , common along wet flush, Sphagnum and cushionbogs (e .g. Hyper icoPlantaginetum rigidae) and a long the mineral shores of grassparamo lakes and ponds on flat to slightly sloping (0-6째) ground . The wid th of the Muhlenbergietum zone, then depends on the slope . On steeper slopes the zone of the Muhlenber gietum becomes narrower. In some places along small streams or drainage rills , the ftfuhlenbergi~tum is temporarily flooded . Species of Breutelia and Sphagnum are almost The darkbrown, peaty upper layer of the clayey soils is rich in organic material. The deeper sandy to clayey layers are grayish-brown to light yellowish-brown . The thickness of the soil is 50-120 em. The upper top soil is slightly acid (pH 4.8). Distribution: The Muhlenbergietum fastigia tae is found from the upper forestline at 3500 m up to the lowermost limit of the superparamo at 4250 m throughout the Colombian Cordillera Oriental. In view of the wide distribution of Muhlenbergia fastigiata, the association must be present also in othe r Andean paramos and in the puna . Ruthsatz (1 977) described Muhlenber gia fastigiata Distichlis humilis salt meadows from the northern Argentinan puna (3500-3680 m). She pointed out that Muhlenbergia fastigiata might be the character species of a distinct syntaxon.

189 109. Agrostietum foliatae ass. nov. (prov.) type: rel. 179; table 26; Fig. 77 lit.: Cuatrecasas 1934 ; photo: Cuatrecasas 1958 , plate 23-1 Physiognomy: The Agrostietum foliatae is an open, small tussock grass vegetation , with a cover of about 20%. The small tussocks have stiff erect blades and conspicuously purplish , contracted inflorescenc e s, and are 25 em high. The bryophytic layer consists mainly of acrocarpous mosses and is only present on the low sandy hummocks under the grass tufts. Minuscule blue algae (Aphanocapsa gervillei) are abundant in the humid , bare glacier sand, and cause a faint purplish hue. Table 26 .

Agrostietum foliatae ass. nov. (prov . )

rel. nr . releve area m2 cover vegetation % soil pH topsoil number species alt. m locality cover % ~/d/;-taxa Agrostietum oliatae : c gros ~s o ~a a Aphanocapsa gervillei Luzula cf. racemosa Polytrichum juniperinum Cora pavonia Ditrichum gracile Calamagros tis ligulata companions: Hypochoeris cf. sessiliflora Anastrophyllum sp. LuciZia sp . Aongstroemia julaceae

179 9 30 s 5. I

172 9 75 s

4280 Coc

5.2 6 4310 Coc

10 20

3 60

..0::.]

..0::. ]

..0::.]

10 20 <I I <I ]+

Both releve s are from the Sierra Nevada del Cocuy ; Bocatoma valley (Boyaca) . Composition & syntaxonomy: Agrostis foliata (previously A. nigriteZZa Pilger) is an (exclusive) charac ter species with a wide distribution in the high , northern Andean paramos from Peru to Venezuela between 3500 and 4700 m. Luzula cf. racemosa, Ditrichum gracile, Polytrichum juniperinum and Lucilia are common asso ciates . In some plac es Calamagrostis ligu lata tussocks are present also (see 60) . Blue algae , mainly Aphanocapsa gervillei (Hass.) Rabenh . (det. Dr. G. H. Schwabe, Plon), are abundant in humid sand. According to Dr. G.H. Schwabe (in litt . ) this is a pioneer species also kno'vn from the high Alps and Surtsey . As in all pioneer communities, the number of species is low (6-7 in 2 releves). The Agrostietum foliatae has affinities to the Carici peucophilaeWernerietum crassae (61) and the Calamagrostis ligulata superparamo communities (see 60). The assoc iation has been described provisionally . It is possible that at a later date also the pioneer community on volcanic ashes and pumice of the Colombian Cordillera Central has to be included in this association . Synecology: This superparamo pioneer grass community is characteristic for humid sandy and silty beaches of superparamo lakes, for floodplains of braided streams. The subsoils there consist of varvae-like sequences of humic clay and coarse sand. Topsoil pH values are 5 . 1 and 5.2. Wind and water det ermine the size and shape of the low hummocks. These are formed by sand-loaded wind and may be carried away by water floods . Bryophytes (e.g . Anastrophyllum sp.,

190

Ditrichum gracile) are able to hold the low sandy hummocks. Ditrichum gr acile occurs on the wind~exposed side; Anastrophyllum sp. is found on the leeward side of the Agrostis foliata hummock (Fig. 7S). Agrostis foliata is a specialized pioneer species on humid sandy superparamo beaches, but is also found as first vascular colonizer on ashes and pumice slopes on Colombian volcanoes (Cuatrecasas 1934, Cleef et al., in press). Some clumps of this grass species may be present in the grass paramos. Distribution: Superparamo beach is well developed in the Sierra Nevada valley) and 4600 m (Ritacuva glacier). co llections made by Dr. J. Cuatrecasas in the Colombian Cordillera Centra l on

vegetation of the Agrostietum fol iatae del Cocuy between 4300 m (Bocatoma According to herbarium labels of such superparamo vegetation also occurs the sandy shores of superparamo lakes.

ROSACEOUS HERBFIELD The herbaceous meadows are dominated by low rosettes with silvery-tomented blades and semi -woody stems and r oo ts, belonging the Rosoideae, Rosaceae. Rosaceous herbfield must be considered as a degraded zonal or azonal vegetation due to intensive grazing by cattle (e.g. 110 & Ill) and frequent burning (e.g. 112). 110. Community of Agr ostis breviculmis and Lachemilla pinnata characteristic rel.: SS4; table 27 Table 27.

Agrostis br eviculmis- Lachemilla pinnata community

rel. no. exp. slope (degree) r e l eve area m2 alt. m locality

SS4

IS 2S 4100 Almorzadero

IS7

7 2 3890 Cocuy

cover %

Lachemilla pinnata Agrostis breviculmis Cerastium sp. Acaulimalva sp. Stachys elliptica Bryum billardieri Hypochoeris sessiliflora Aciachne pulvinata Geranium sibbaldioides Aphanactus sp. Gentianella corymbosa Or eomyrrhis andicola Erigeron sp. Leptodontium cf. pungens

80 40 2 <I <I <I 2S

Bartramiaceae Campylopus spp.

Lachemilla or biculata Rumex acetosella Veronica serpyllifolia Potentilla heterosepala Senecio niveo- aur eus

3S 2S ~I

IS <I <I 30

2 I+ ~ ~

I <I <I

.19J

Physiognomy: This community forms a grassy herbfield of dense growing low rosettes (LachemiZZa, Hypochoeris, Aphanactus, Oreomyrrhis, AcauZimaZva), the height of which is not more than 10- 15 em . The cover of the bryophyte layer consisting of a few acrocarpous mosses is 1%. Composition & syn taxonomy: Low rosette p l an ts with silvery indumented pinnate leaves of LachemiZZa pinnata are dominant ; Agrostis brevicuZmis and Hypochoeris sessiliflora are subdominant. LachemiZZa pinnata is a polymorphic species , widely distribu t ed f r om t he Argenti nan puna to the north Andean paramos of Colombia and Venezuela and the Mexican mountains. The paramo meadows with LachemiZZa pinnata represent a separate well-defined syntaxon, which will be described when more releves become available. Ruthsatz (19 77 ) reported a LachemiZZa pinnata-EZeocharis aZbibracteata association (p r ov . ) from the Argentinan puna between 400 and 4300 m. This community fringes cushion bogs, and on the basis of its composition and ecology rather belongs to the Wernerion pygmaeae (prov . ) Ruthsatz 1977 , i.e. the Wernerietea ( prov.). The Agrostis brevicuZmis- LachemiZZa pinnata paramo has a differen t syntaxonomical position. The gr eatest affinity is to the Agrostio brevicuZmis- LachemiZZetum orbicularis (Ill), the Aciachnetum puZvinatae (107) and to other paramo communities with Agrostis brevicuZmis (25). Synecology: Xeromorph ic rosette meadows on moderately sloping ( 7- 15掳) dry ground, where the Aciachnetum is absent . I n the Paramo del Almorzader'o LachemiZZa pinnata is domin an t in depressions and gullies on calcareous slopes up to 4330 m, with occasiona l rain water. In 路t he Sierra Nevada de l Cocuy rosettes o f LachemiZZa pinnata were seen locally bordering the Aciachnetum

puZvinatae. The humic, brownish-black, sandy so i ls are s t ony and shal l ow. The upper soi l layer in rel. 157 is weakly acid (pH 5.4- 5.5). Grazing and manuring by cattle is common, as indicated by the presence of Rumex actoseZZa and Veronica serpyZZifoZia. LachemiZZa pinnata has a wide ecological range and occurs on all kinds of substrat e .

I I I. Agrostio brevicuZmis- LachemiZZetum orbicuZatae ass. nov. t ype: re l . 624; tab l e 28; Fig. 75 l it. : Cuatrecasas 1934, 1958; Oberdorfer 1960; Cleef et al, Table 28 .

Agrostio brevicuZmis-LachemiZZetum orbiculatae ass. nov .

rel. nr . rel. area m2 slope (degree) number of species alt. m locality

576 577 4 4 3 8 9 3740 4000 TPN Al m

6 18

624 4

5 4 3920 TPN

12 3800 TPN

-cover ----- -%

& o taxa Agrostio-LachemiZZetum Lacnem~a orb~cuZata

c,d

c c Agrostis brevicuZmis

Leptodontium pungens Veronica serpyZZifoZia Hypochoeris sessiliflora Agrostis cf. haenkena Festuca breviaristata Rumex acetoseZZa Taraxacum sp. LachemiZZa pinnata Cerastium sp.

80 10 3

85 5

I+ I

I 35

I I+ I 10

I+

press.

192

Arenaria sp . Bromus lanatus Calandrinia acaulis Halenia sp. Ranunculus peruvianus Salvia sp. Lupinus humi.f,~sus Oreomyrrhis andicola Senecio repens Localities: Alm TPN

(576) (577) I+

(624)

I+ I

5 3 I

Paramo d.e l Almorzadero Parque Los Nevados , Cordillera Central

Physiognomy: The Agrost1:o- Lachemilletwn orbiculatae f orms low herbaceous meadows on flat or slightly sloping ground, dominated by semi-woody, microphyllous, rosaceous ground rosettes; e.g. "cryptolignum" sensu Cuatrecasas (I 934). Composition: Lachemilla orbiculata is a (s e lective) chara cter species. This polymorphic species (E . G.B. Kieft, pers . comm.) is native to the high Andes from Pe ru to Venezuela. In paramo communities a number of meadow species is associated e.g. Agrostis breviculmis, Leptodontium cf . pungens, Veronica ~serpyllifolia, Hypochoeris sp., Lachemilla pinnata, Arenaria sp., Gnaphalium

antennarioides. The Lachemilletum orbiculatae was originally des cribed by Cuatrecasas (1934 , 1958) from clearings in the upper part of the Andean forests in the Nevado del Tolima (2600-3300 m) and near Bogota (2700-2950 m) . A number of vascular plants may be codominant or predominant and Cuatrecasas ranke d such stands respectively at the subassociation or association level. The Lachemillion orbiculatae Cuatrecasas 1934 corr. Cuatrecasas 1958 was originally erected for the forestclearing communities of the Lachemilletum orbiculatae and the Dactyletum glomeratae Cuatrecasas 1934 . This alliance may also include the paramo vegetation of the Agrostio br eviculmis- Lachemil letum orbiculatae. The forestclearing communities with Lachemi lla orbiculatae apparently belong to several associations and they are distinctly different from the AgrostioLachemilletum orbiculatae by a number of speci es. Among the most common species are Lachemilla aphanoides, Salvia sp., Spilanthes americana (Mutis)Hieron. (Comp.) , Gnaphalium spicatum, Trifolium spp ., Paspalum bonplandianum,

Anthoxanthum odoratum L., Dactylis glomerata L., Holcus lanatus L., Hydrocotyle bonplanqii and Agrostis perennans. Alien species are prominent . Such communities commonly fringe roads and paths through the upper Andean forest and shrubparamo. Oberdorfe r (1960) reported a similar community at 2800 m above Quito, Ecuador . As to the Agrostio- Lachemilletwn orbiculatae it was observed that Lachemilla pinnata is associated in the dry paramos of the Sierra Nevada del Cocuy and the Paramo del Almorzadero . In paramo meadows in the Colombian Cordillera Central (Parque Los Nevados) , tufted species of Festuca and Taraxacum sp . are characteristic (Cleef et al ., in press) . The greatest affinity is with the Aciachnetum pulvinatae and the Agrostis breviculmis-Lachemilla pinnata community. Synecology: This community is characteric for intensively grazed and manured, (slightly) humid, l eve l ground in the paramos, where it spreads easily in places where the tussocks disappear. Mats of Azorella pedunculata and Plantago rigida are associated in one place in the Paramo de Guantiva (rel. 40). Soils are humi c clay or sand and moderately acid (pH 4.5-5 . 0) . Distribution : In the study area the Agrostio breviculmis - Lachemilla orbiculatae is distributed between 3 700 and 4000 m (Cocuy- Almorzadero). This type of meadow is common in the neighbourhood of ranches . In the paramos

193 of the Parque Los Nevados in the Colombian Cordill e ra Central the Agrosto br evicuZmis - Lachemilletum orbiculat ae is present up to 4200 m (Cl ee f et

al . ~

in press) . 112. Community of Acaena cy l indri s tachya Fig. 13 , 26 lit. : Van der Hammen & Gonzalez 1960, Cleef 1978 , Vareschi 19 80

Acaena cy lindris t achya is a conspicuous low rosette plant of the zona l open dry bunchgrass paramo (see 14, 16, 17, 19). Locally, as mentioned by Vander Hammen

& Gonzalez (1960) and Cleef (1978) , Acaena cylindristachya tends to be dominant , and patches are present in zonal grass paramo . In the study area thes e stands are mainly found in the northern paramos between 3450 m (Paramo de Guantiva and Pisva) and 4000 m (Sierra Nevada del Cocuy ). The Pa ramo de Guasca conta ins a small patch of Acaena cylindristachya at 3350 m. In the Sierra Nevada de S. Marta, Acaena路 cylindristachya herbfield is f ound on the Alto La Cumbre (3500-3700 m) and in the Donachui valley (4300 m) according to Van de r Hammen & Gonzale :: (I 960a) , and Ran gel et al. (in prep.). The Acaena cylindristachya rosette s have a cove r of 40-90 %; c ommon associates are Lachemilla sp ., Polytrichum juniperinum~ Hypericum spp . Hypochoer is sess i liflora~ Gent ianella corymbosa~ Halenia sp . , Agrostis trichodes. Acaena cy lindristachya herbfield is supposed to develop whe re bunchgrass e s disappear by intensive grazing and repeated burning . This view is supp orted by a fieldstudy on the Alto La Cumbre in the Sierra Nevada de S. Marta where transitions from bunchgrass to rosaceous herbfield have been observed. Acaena cylindristachya vegetation is well developed on c oncave slopes and may pas s into another rosaceous herbfield , the Agrostio- Lachemilletum orbiculatae (Ill) on level humid ground, where water temporarily accumulates . This vege tation has floristic affinities with the Acaeno- Plantaginetum sericeae (18) , and also with the Aciachnetum, the Lorenzochloetum and zonal bunchgras s communities with Acaena cylindristachya . Acaena cylindristachya was not found in the paramos of the Colombia Cordillera Central .

SCREE AND OUTCROP VEGETATION The exclusively epilithic vegetation, that is not depending on soil, has not been studied. Cryptogams restricted to such epilithi c vegetation inc lud e spe c i e s of crustose lichens , and Usnea~ Umbilicaria~ Neuropogon~ Parmeli ace ae , Ster eocaulon (Boekhout, in prep. ) Grimmia~ Andreaea rupestri s~ Rhizocarpon cf. geograficum (rare). 113. Moss ve ge t a tion of Rhacocarpus purpuracens and Racomitrium crispulum Bare , steep, rocky surfaces ("lajas") in the grass paramo and in the lower superparamo within reach of the upp e r condensation zone, may support brownish moss ve getation of Rhacocarpus purpurascens and of Racomitrium spe ci e s . Usually they grow together and one of them is predominant . Rhacocarpus purpurascens mats dominate unde r permanently we t conditi on s, either a tmospherically or edaphi cally by seep age . We t Rhacocarpus mats on steep r ocky slope s are brownish to strongly orange from a distance. They are common in the bamboo paramos (e.g. Andabobos , Q. Sitia l e s vall ey in the Paramo de Sumapaz) and in the lower superparamo of the upper condens a tion zone ( e.g . Nev ado de Sumapaz , and to a lesser ex t ent in the s ummit area of the Paramo del Almorzadero ). Racomitr ium crispulum take s over when the conditions are l e ss humid, edaphica lly as well as atmosphe rically, or towards higher elevations .

194 In grass paramo watershed areas (3600-3900 m) the crests are normally c overe d by c loud banks coming from the wet side of the Cordillera. Racomitrium crispuZum vege tation is abundant on those crests, mi x ed with whitish Racomitr ium Zanuginosum , previsously not known from the Colombian Andes. In the l e ss humid upper condensation zone on the NW side of the Nevado Ruiz and on othe r volcanoes in the Parque Los Nevados in the Colombian Cordillera Central, Racomitri um crispuZum dominates on rocky surfa ce. Rhacocarpus purpurascens only becomes prominent in seepage zones (Cleef et al., in press). This vegetation type was also seen on the volcano Purace further to the south (Dr. T. van der Hammen, pers. comm . ) . 114. Community of ThamnoZia vermicuZaris and AZectoria c f. ochroZeuca This vegetation type is extremely rich in lichen species. Phisiognomically and partly floristically it is r eminiscent of arctic-a lpine li chen communitie s . The st ands are small and r e stricted to exposed tocky ridges, ledges and outcrop s on the crest, expecially in wat e rshed areas. This lichen community is characte ristic for divide s with wet bamboo paramos on one side. The habitat is permanently covered in fog and clouds. Lichens are thriving well under these conditions of high atmospheric humidity. Stands on "lithosols" studied in the Paramo de Pisva and Paramo de Palacio (3700-3800 m) have in common: I) a hi gh cover (70-80%) of lichens, especially the fruticose forms; 2) a low cover (1-10 %) and number of vascular species (not more than 5). Va scul ar species common both areas are LuzuZa r acemosa, Grammitis moniZiformis and Draba sp. (4696A). Common li chens are ThamnoZia vermicuZaris, AZectoria cf. ochroZeuca (4576 , 5235), Oropogon Zoxensis, LeprocauZon aZbicans, StereocauZon atZanticum, CZadia aggr egata, UmbiZicaria sp. (4581), Everniastrum catawbiense, Cor a pavonia, CZadonia andesita, C. isabeZZina, and speci es of SiphuZa and CZadonia subg . CZadina : e. g . CZadonia coZombiana, C. boZiviana. Common bryophy t es are CampyZopus richardii, C. pi t t ieri, JamesonieZZa rubr i cauZis, Rhacocar pus purpurascens and Riccardia sp. (4585). Br euteZia kar s teniana, rare in the study area, is found in the exposed windswept habitat, together with some taxa from higher altitudes (superp ar amo): e . g. Dr aba, ThamnoZia, LuzuZa racemosa,

LachemiZZa nivaZis, Jamesonia goudotii . The lithosols a re overlying sandstone bedrock, and they are strongly (pH 4.24.4) to moderately acid (pH 4.9) . The habitat is frequ ented by SyZvi Zagus and birds . 115 . Community of Senecio niveo- aureus and

Er ythr ophyZZopsis andina

This rare high altitude moss community is dominated by the acrocarpous

ErythrophyZZopsis andina with a conspicuous red colour. According to Zander (1977) this species is widely distributed in the tropical Andes from Argentina to Colombia. In the study area Erythr ophy ZZopsis andi na vegetation was studied at 3950 m on the Alto de Torquita in the Paramo de Sumapaz. A gregarious moss ball carp e t of reddish to dark-brownish Er yt hrophyZZopsis andina practically covers the humid gravelly or c layey soil, in which frost heaving is a common f e ature . This moss community was found in depressions in the upper grass paramo on level or gently sloping ground (up to 5째). Er ythrophyZZopsi s andina (dominant) is accompanied by Senecio niveo- aur eus , and by Dr aba sp. (7750), Luci Zia sp. (754 8 ) and CZadonia sp. (7551), all with a cover of 1-5 %). A similar community was also studied in the lower superparamo in the calcareous summit zone of the Paramo de l Almorzadero at 4300 m (rel. 558). Er ythrophyZZopsi s andina is further known from humid epilithic habitats in rockshelters and caves in the paramos of the study area between 3700 and 4300 m.

195 Notes on bryophyte communities : Moss-dominated communities are common in the open bamboo paramos of our area. Sphagnum bog is a striking example, but paramo mires contain a ls o mossy communities. The CaZamagrostion ZiguZatae comprises s ever al syntaxa and communities dominated by resp . CampyZopus cavifoZius, Sphagnum sancto-

josephense, DrepanocZadus aduncus and CaZZiergoneZZa cuspidata . the Wernerion crassae-pygmeae also contains aquatic moss es with high cover : e .g. Rhacocarpus purpurascens, Sphagnum cycZophyZZum, DrepanocZadus revoZvens and Scorpidium scorpioides. On decayed cushion bogs of the Hyperico PZantaginetum r igidae a closed mat of BreuteZia chrysea and B. aZZionii may be developed.

Rhacocarpus- Racomitrium ssp . communities cover rocky surfaces and humid exposed ridges in the grass paramo and in the wet upper condensation zone in the lowermost part of the superpar amo. The liverwort s pecie s Herbertus subdentatus and H. acantheZius determine the reddish aspect of the upper conden sation belt vegetation in the summit area of the Nevado de Sumapaz. Some communities are restricted to streams; here thrive the rheophy ti c Dendrocryphaeo- PZatyhypnidietum riparioides and the PhiZonoto- Isotachidetum serruZatae. The latter association consists of liverworts. In the Colombian Cordillera Central another liverwort community of Nardia succuZenta is present in warm water of sulphur-co,ltaining volcanic springs.

116. Community of Senecio surrrrrrus Thi s community is only known in the study area in humid crevices in the ca lcareous rock of the summit area (4000-4200 m) on the Nevado de Sumap az. The abundance of species and the high cover of liverworts , especially of Metzgeria gigantea and PZagiochiZa dependuZa and further Porotrichum sp. ( 8 165),

Amphidium cyathicarpum, Bartramia angustifoZia, Mohrinia ehrenbergiana, RaduZa sp. (8156),- PZagiochiZa cuatrecasasii, Herbertus subdentatus, e tc . reflec t a well-developed upper condensation zone. Draba sp. (yellow pe tals) , VaZeriana pZantaginea and other species of the Racomitrium- VaZeriana pZantaginea community (27) are conspicuous also. Senecio summus is the most charac teristic herbaceous species, reported here for the first time from the Colombian Cordillera Oriental. It was only known from the high paramos of Central and northern Ecuador and the Colombian Cordillera Central (P a rque Los Nevados), where it is restricted to similar habitats be tween 4000 and 4400 m. Senecio summus belongs to the sect . CuZcitiopsis Cuatr., whi ch comprises high altitude specie s endemic to the tropical Andes from Peru to Colombia. The blackish clayey lithos o l in the loca lity at 4170 m on the Nevado de Sumapaz is slightly acid (pH 5. 7). Contrasting with the ri ch community of Senecio summus is tha t of the endemic S. pasqui- andinus (S. se c t Hypsobates Cuatr . ), which is common between quartzite boulders in the lower part of the superparamo, mainly on the humid side of the Sierra Nevada del Cocuy (4200-4300 m).

117. Ro ck shelter vegetation lit .: Vareschi 1958 Dry and humid rockshelters are common in the paramos of the study area. In several of them between 3500 and 4350 m, a cursory inventory ha s been made when sheltering for heavy rain. Some of the species that are restricted to this habitat are Cystopteris diaphana, Asplenium triphyZZum, EZaphogZossum Zindenii, Cruciferae (probably

Lepidium bipinnatifo ZiumJ,Br achypodium mexicanum, Parietaria debiZis , Urtica beZZotaefoZia, Tortu Za andicoZa, Anoectangium aestivum, Mor inia ehrenberginana,

196

Miconia chionophila, Kingiobryum paramicola. Ferns are common in lower superparamo rockshelters in the upper condensation belt at 4300-4350 min the Sierra Nevada del Cocuy near Patio Bolos (Arauca). Among them are Asplenium castaneum, A. triphy llum, Cystopteris diaphana and Polystichum polyphyllum. Poa cf. pauciflora (8726) is prominent in the super paramo rockshelters, especially as humid scree vegetation at the base of steep wet cliffâ&#x20AC;˘s. This was observed on the Nevada de Sumapaz, the Pan de Azucar (4270 m) in the Paramo de Guantiva, and in the Sierra Nevada del Cocuy and S. Marta (4100-4400 m). Common vascular species in grass paramo rockshelter are Salvia killipiana,

Parietaria debilis, Urtica bellotaefolia, Cinna poaeformis, Bromus unioloides B. cf. lanatus, Brachypodium cf . mexicanum (5369, 7371), Cruciferae (5367, 7370), Nertera granadensis, Muhlenbeckia vulcanica, Stachys sp. (7368, 7398), Echeveria sp., Eriosorus hirsutulus, Elaphoglossum lindenii , Sibthorpia repens, Draba spp., Miconia chionophila, Arenaria sp., Bidens triplinervia, Eupatorium (Ager atina ) gracile . Among the numerous cryptogams the mosses Anoectangium aestivum, Distichium capillaceum, Amphidium cyathicarpum, Bryum argenteum, Morinia ehrenbergiana, Br eutelia integrifolia, Bartramia mathewsii, B. potosica, Kingiobryum paramicola, Philonotis spp. and the liverworts Her bertus acanthelius, Metzgeria sp., Pycnolejeunea subg . Strepsilejeunea, ana Anastrophyllum EroZZii are characteristic The presence of va rious floristic elements from dwarfforest and upper forest line in paramo rockshelters reflect the favourable humid microclimate .â&#x20AC;˘ Superparamo taxa may be present in lower areas such as species of Draba and

Erigeron chionophilus. Sheltering cattle and deer may have introduced the nitrophytic taxa as Crucife rae , Parietaria, Urtica , Bidens, Rumex acetosella.

197

OTHER COMMUNITIES Some other communities, the syntaxonomical position of which could not be established with certainty , will be treated below . 118 .

AzoreUetwn muZti.fidae ass . nov . (prov . ) type : rel. 276 ; table 29 ; Fig . 29 photo : Gradstein et al . 1977, plate 2D ; Cleef 1978 , photo 177 , 178 . lit .: Weberbauer 1945, Cleef 1978

Physiognomy: The association concerns cushion vegetation of vascular plants . The well-developed leptophyllous cushions are 30-40 em high . The thick moss stratum (up to 20 em) may cover the cushions for 80% or more, depending on age of the cushions . Table 29

Azorelletwn multifidae ass. nov . (prov . )

rel . nr . releve area cover dwarfshrub vascular cushion plants bryophytes height cushions bryophyte layer slope (degree) soil pH top soil 1 m depth approx. number of species alt . locality locality

276 2 18m 6% 60% 35% 40 em 20 em c/s 5. 4 5.9 45 4100 m Nevada de Sumapaz (Meta)

cover % A ~7d=%=~ taxa Azorelletwn multifidae c Azorella multifida 60 Breutelia chrysea 25 Diplostephiwn rupestre 5 Plantago rigida 5 Draba sp . (cf . 1300-yellow petals) 3 Senecio niveo-aureus 3 Herbertus subdentatus 5 Zygodon cf . pichinchensis (7982) 2

Senecio vernicosus Draba sp . (cf. 1310-white petals)

Valeriana plantaginea Senecio summus Campylopus pittieri Anastrophyllwn leucostomwn Tortula andicola Satureja nubigena Onrisia muscosa Oreomyrrhis andicola Campylopus tunariensis Cetraria sp .

< I+ < ]+ < 1+

<I + <1+

Hypochoeris sessiliflora (yellow) , Senecio formosus, Gentiana sedifolia, Ophioglosswn crotalophoroides, Carex cf . tristicha, Geranium confertwn, G. sibbaldioides, Lysipomia sphagnophila ssp . minor, Cerastium imbricatwn, Bryum ellipsifoliwn, Hypnwn eupressiforme, Brachuthecium sp . , Racomitriwn crispulum, Peltigera canina, Parmeliaceae, Leprocaulon albicans, Jungermanniales (7977), Oropogon loxense, Brywn argenteum, Bryum sp . , Riccardia sp ., Philonoti.s cf. revoluta, Fissidens sp. (7978), Calliergon sp ., Barbula sp. , Stereodon hamatus .

With a cover lesser than 1%

198

Composition & syntaxonomy: Azorella multifida is a selective char a ct er specie s. Br eutelia chr ysea is c ons picuous on decay ing cushions of AzoreZZa. Br yum eZZipsifoZium is only known fr om high areas on Kilimanj a ro, and from Venezuela , Colombia, Bolivia and Tierra de l Fue go (Ochi 1980) . Synecology: The AzoreZZetum muZtifidae c onstitutes the cushion vege t a tti on of in humid small vall eys in the upper reaches of the Nevado de Sumapaz. The c ushions are r e stri c t e d to the upper condensation zone with a permanently hi gh humidity. The pH of the br own to yellowish-brown deep colluvial clayey and sandy soil is 5 . 4 in the top layer , and 5 .9 at a depth of 1 m. Suc ce s s i on after decay of the AzoreZZa muZtifida cushions may lead her e to the Senecionetum vernicosi ( 85) . Furthe r data on the synecology of the Azor eZZetum muZtifidae are given in Cl ee f (1978). Distribution : Cushion vegetation of the Azore ZZetum muZtifidae is well deve loped betwe en 4050 and 4200 m on the Neva do de Sumapaz; also in sma ll patches on other high peaks and in watershed areas of the Paramo de Sumapaz above 3900 m tha t reach into the upper condensation zone. Solitary cushions of Azor eZZa cf. muZtifida were s een on the high volcano Neva do de S. Isabel in the Colombian Cordillera Central ; they a re supposed to be pres ent in the Ecuadorian cushion paramos (0ll ga a rd & Balslev 1979) and Peru (Weberbauer 1945) . 119.

Bamb oo grove of NeuroZepis aristata cha r ac teristic rel .: 17; table 30

Physiognomy: This type of high a ltitude bamboo grove oc curs near to patches of upper Andean dwarfforest . The dense bamboo layer is up to 3m high an has a cover of 100%. A dwarfshrub layer and a low herbaceous layer ar e almost ab s ent. The well-shade d ground layer consists almost entirely of hy grophyti c bryophytes with a cover of about 50% . Composition: The grove consists of the oad bamboo species NeuroZepis aristata. Trichocolea sp. (1212) is dominant in the moss layer , w~ich contains a number of hygrophy tic taxa , e.g. Metzgeria Zeptoneura~ Riccar dia spp ., Fissidens and Chor isodontium setaceum. Tabl e 30

Neurole pis aristata bamboo grove

rel. nr. a lt. lo c. incl. releve area m2 soil cover 路% N~~~oi~pis aristata

SwaZZenochZoa tesseZata Baccharis macr antha ssp .denticuZata Ribes sp . Geranium sibbaZdioide s Miconia cZeefii. Per eromia hispiduZa TrichocoZea s p . (1 2 12) Metzgeria Zeptoneura Riccardia sp. (1 21 8)

17 3635 m Nevado de Suma paz 20掳 8 humic clay 100 5 I I I I

30 10 5

Fissidens sp. (1216) Riccardia sp. (1215) PZagiochiZa sp. (1217) acro c arpous moss (1214)

Chorisodontium setaceum cf. PZagiochiZa sp . (1220) hepaticae div . spp . (1 2 11, 1221 , 122 7)

Sphagnum magellanicum PeZ t iger a doZichor hiza CZadonia isabeZZina

199

Synecology: Steeply sloping ground in small protected valleys near the upper cloud forest line. The upper soil layer consists of sandy, humic clay (pH 4.6). The bryophyte cover has strong floristic affinities to that of the superhumid upper part of the cloud forest, which contains taxa indicative of high humidity. The presence of Sphagnum mageZZanicum indicates boggy conditions. NeuroZepis aristatais also a characteristic species of the upper Andean forest and high Andean dwarf forest in the Parque Los Nevados, Colombian Cordillera Central (Cleef et ~1., in press). Distribution: NeuroZepis aristata, according to Me Clure (1973), is found throughout the border area of humid Andean forest and bamboo paramo from Chachapoyas in NE peru, to Colombia, between 2900 and 4000 (4500 ?) m, locally in large, almost impenetrable clumps. In the Colombian Cordillera Oriental this odd bamboo is found in some places on the humid side of the mountains between 3000 and 3750 m.

120.

Dense EspeZetia stemrosette commun1t1es Fig. 78 (also Fig. 27, 52, 54, 55, 72)

Patches with dense Es peZetia stemrosettes are common from the ÂŁcrestline up to the superparamo. Such macrophyllous stemrosette community is found in protected places, mostly in depressions on humid or wet, boggy ground. Stemoro s ettes of EspeZetia, also grow closely togethe r along the humid sides of wet valleys. EspeZetia has a cover of 35-80%. The higher cover of the stemrosettes causes the grass bunches to be largely replaced by low matted brownish~ to dark-greenish skiophytic species. The floristic composition is variable and depends on drainage, substrate, shadow and altitude. Species of PaepaZanthus (e.g. P. karstenii, P. andicoZa var. viZZosus) are characteristic in this type of stands on dry sloping soil, mainly in the subparamo. Other frequent taxa are low shrubby species, e.g. Baccharis tricuneata, ArcytophyZZum muticum, Vaccinium floribundum var. ramosissimum and Disterigma empetrifoZium . Oritrophium peruvianum ssp. peruvianum fma.

intermedia , Carex pichinchensis, Rhacocarpus purpurascens, BreuteZia aZZionii are characteristic in dense EspeZetia Zopezii stands (3500-4250 m) on humid,

clayey soil (pH 5.1-5.8 in the rootzone) in depressions and in the heads of wet valleys. These stands fringe such wet valleys downslope to the forest line. In rel. 117, CampyZopus paramoensis dominates this habitat. This species was previously only known from Costa Rican paramos. Characteristic taxa in Sphagnum bogs may appear in dense EspeZetia stands (e.g. E. chocontana, E. muriZZoi, E. incana ) on wet peaty ground in the lower paramos. Such stands rather belong to the communities of the paramo Sphagnum bog formation.

121. Commity of Orthrosanthus chimboracensis The iridaceous Orthrosanthus chimboracensis is endemic and restricted to the lower paramo. On the dry side of the mountains where shrub paramo is replaced by low herbaceous mats after cutting timber, burning and grazing, large tuf ts of Orthrosanthus chimboracensi s var. chimboracensis b e come predominant. This is seen in many places in degraded subparamos facing the high plains of Bogota, in other parts of Cundinamarca and Boyaca, and on the dry side of the Sierra Nevada del Cocuy and the Paramo del Almorzadero.

200 In sloping dry depressions and gullies from the bunchgrass paramo towards the former forestline above Belen (Boyoca), Orthrosanthus chimboracensisdominated herbfield is common. The stands are developed on thick colluvial black sandy clay, slightly acid in the upper part (pH 5 .4), and they are present between 3400 and 3650 m. Such an iridaceous herbfield (I m high, 10째 slope) at 3645 m contained the following herbaceous species: Orthrosanthus chimboracensis (dominant) Bidens triplinervia Lachemilla spp. Paspalum bonplandianum

Ranunculus peruvianus Acaena cylindristachya (locally codominant) Rhynchospora sp. Calamagrostis sp. AgrosUs Lupinus sp. Oxalis sp. Conyza sp.

Viola humilis Noticatrum marginatvm Geranium sibbaldioides Gnaphalium sp. Bartsia sp. Digitalis purpurea L. Anthoxanthum odoratum L. Holcus lanatus L.

201

IV.

DISCUSSION AND CONCLUSIONS

GENERAL COMMENTS The open paramo belt contains a much larger number of plant communltles than the Andean cloud forest belt, at least when there are no human activities. This is typical for the high mountains of tropical and temperate :!.atitu.c!es. For North America, Komarkova (1979, fig. 73 & table 29) presented quantitative data for the Front Range, Colorado Rocky Mountains. At lesser altitudes the vegetation from the Andean forest to the open paramo shews the presence of an increasingly high number of different zonal and azonal plant communities. This is corroborated by the present study, and by ECOANDES studies in Andean forests a11d paramos in the Cordillera Central (Cleef et al., in press), and the Buritaca transect in the Sierra Nevada deS. Marta (Rangel et al., in prep.). The formerly glaciated paramo belt with numerous lakes in boggy valleys, separated by dry moraines, represents a diversified landscape with a large variety in habitats and vegetation. The diversity is expressed by the floristic composition of the vegetation as well as by its structural character (height, growth form). In the superparamo, solifluction and other phenomena are responsible for the diversity in habitat and plant cover. In this respect, conditions in the paramo and superparamo belt are in contras t with those in the lower paramo zones and forest belt. Some general conclusions will presently be discussed on the relation of the paramo veg~tation and its growth forms and leaf sizes to temperature and humidity, and also on the phytogeography of the paramo vegetation. Vegetation in relation to temperature and humidity The open vegetation in the equatorial high mountains is exposed to a diurnal climate, cl,aracterized by daily fluctuations in temperature, with the lowest values at night and the highest in daytime.Temperature is the main determining factor, with humidity as an additional agent; the t "l-70 are interre lated to a certain extent. 路 The paramo vegetation in the study area shifts in accordance with these two major :actors. The factor temperature is mainly determined by the temperature with increasing altitude (the lapse rate is generally 0.60C per 100m). This is the most important gradient and it determines the shift from woody to graminoid and other herbaceous zonal paramo vegetation from the forest line up to the nival belt (Fig . 6, 8). As a consequence of prevailing low temperatures, the uptake of water and nutrients by the roots of vascular plants becomes lower and transpiration by the leaves slows down. Species of tropical or,gin apparently are less adapted to this environment; this may cxp1ain the predominance of temperate (wide temperate, holarctic, austra l-antarctic) genera in the highest areas of the paramo belt (Vander Hammen & Cleef, in press). Towards higher elevations atmospherical radiation increases, and plants seem to protect themselves against the high radiation by developing various kinds of leaf coatings or by changes in leaf colours. In areas with permanent high atmospherical humidity, however, radiation has distinctly less effect. The factor moisture is mainly determinated by the gradient from low to high (atmospherical) humidity . High moisture conditions cause narrow temper ature

202

Table 31

PARAMOS COLOMBIAN CORDILLERA ORIENTAL

number of months with high precipitation I) mean total 100 mm

50 mm

water deficit I)

annual precipitation

===================================================================~~l========== zonal bamboo paramo 2 bamboo-bunchgrass paramo

3 bunchgrass paramo

6 - 9

H-

I) based on climatediagrams (Fig . 3)

10 -

2000 1100- 2000

6 - 10

0 -

1100

203 amplitudes and low values of nightly radiation. Thus, oligothermic conditions are more pronounced on the humid side of the Cordillera, and this causes asymmetrical altitudinal vegetation belts (Lauer 1976, 1979; Cleef 1979b; Van der Hammen et al. 1981). This is most prominent in the so-called "condensation belts" near the upper forest line, and along the lower border of the superparamo, especially on the wet side of the Cordillera (Fig. 6 & 8) . The condensation belts are botanically characterized by : I) a high cover and abundance of terrestric and epiphytic bryophytes; 2) a conspicuous abundance of plant species; 3) presence of woodiness (due to favourable temperatures) in the upper condensation belt, as indicated by such specialized composites as species of Loricaria,Senecio and DipZostephium. Adjacent zonal vegetation is herbaceous, however; 4) relatively larger leafsizes of vascular plants and bryophytes than in the adjacent zones; and 5) presence and high cover of bamboos (usually belonging to two or three genera) in the forestline-condensation belt. High atmospherical humidity is most prominent in the lower part of the paramo belt. Physiognomically, this can be concluded from the occurence of (dwarf) bamboos in zonal and azonal vegetation, and of numerous bogs (Fig. 6 & 8). Thus, three main types of paramo grassland may be recognized (Fig. 79): I) bunchgrass paramos, practically without bamboos (e.g. communities 14-20)

2) bamboo-bunchgrass paramos or bunchgrass paramos with bamboos, more or less restricted to boggy valley floors and slopes (e.g. communities 10-20), and 3) zonal bamboo paramos with a strongly lower cover of bunchgrasses (communities 10-13). Zonal bamboo paramos are restricted to the lower part of the paramo belt. Atmospherical humidity generally decreases with altitude (Weischet 1969, Lauer 1979; this study Fig. 3 & 4), and thus zonal lower bamboo paramo passes into bunchgrass bamboo paramo. At greater heights, bamboos bec.om.e more restricted to moist depressions and the bamboo grassland is gradually replaced by an (upper) bunchgrass paramo (community 20). Edaphic factors controlled by physiography act most strongly on the presence and distribution of dwarfed bamboo vegetation in grass par amos belonging to group 2, which probably covers the greater part of the study area. The presence and cover of bamboos in comparison to bunchgrasses has been discussed in relation to annual precipitation (Cleef 1978, 1979a). It is now evident that distribution, cover and height of the bamboo vegetation are determined also by other interrelated factors, e.g. humidity, physiography and temperature. In order to prove the interrelation of these factors, pluviometric data have been collected from different altitudes in the paramo and the upper part of the Andean forest belt, where field work has carried out. Most of these pluviometric stations are located in the southern part of the study area in bunchgrass paramos where, depending on humidity and elevation, bamboos may be common also. In the most humid bunchgrass paramos the area of bamboo-covered valley and slope bogs is rather large. A close correlation may be made with the duration of the humid period(s), calculated as the period during which the precipitation curve rises above the temperature line on the climatic diagram (Fig. 3), the mean annual precipitation and the altitude (Fig. 80; table 31). Lauer (1952) based his humid periods on the formula of De Martonne. Basically, not many differences can be noticed with the method used in the present study when both methods are applied to the lower part or the paramo belt of the upper Andean forest. Mainly climatically determined boundaries could be provisionally recognized between the bunchgrass paramos, the bamboo-bunchgrass paramos and the bamboo paramos. In the bamboo-bunchgrass paramos the boundaries are spatially controlled by the physiography. These boundaries are still provisional, however,

204 as they have to be confirmed by additional pluviometric data, especially from the atmospherically wettest and driest paramos. In conclusion, the relation between altitude, climate and zonal paramo vegetation is depicted in Fig. 81.It is constructed in a similar way as the "ecograms" published by Ellenberg (1975, 1979) for the Ecuadorian and Peruvian Andes. From Fig. 81 it is apparent that, along a given altitudinal gradient in the grass paramo, the differences in humidity and temperature c~use different types of paramo vegetation. The climatic relations of paramo and puna vegetation have been dealt with by several authors. According to climate diagrams (Fig. 3 m, i) from the most arid paramos in the study area (Paramo de Berlin, 3230 m; El Hato, 3150 m), the period of water deficit lasts not much longer than one month. Ellenberg (1975, 1979), assigned paramos to "perhumid" and "euhumid" supraforest climates (humidity classified following Lauer 1952) in the Ecuadorian and Peruvian Andes, whereas moist puna is present under "subhumid" and semihumid" climatic conditions. Some climate diagrams published by Walter et al. (1975) from about equally high altitudes in the Peruvian and northern Bolivian Andes (e.g. Caillona 3960 m, Puno 3822 m) are indeed strikingly similar to paramo climate diagrams. Likewise, the climate diagram of the Venezuelan lower superparamo of Pico de Aquila (Mucuchies) at 4118 m is surprisingly similar to that of Cerro de Pasco (4350 m) in Peru, but it should be noted that the snowline is situated much higher here than in the northern Andes (Troll 1968). The number of humid months was determined by Troll ( 1968) and Lauer (1979) as 10 - 12 for the paramos, 7 - 10 for the moist puna, 4! - 7 for the dry puna, and 2 - 4! for the thorn puna. In climate diagcams along an E - W transect in the southern Peruvian Andes or from NE to SW through the Peruvian uplands a similar relation can be noticed (Walter et al. 1975; Ellenberg 1979). The length of the deficit period increases in SW direction: e.g. Cuzco (3380 m- 3! month), Jauja (3450 m- ca. 5 months), Galeras Pampa (4000 m - ca. 5 months, this paper). Going from per- and euhumid conditions to subhumid and semihumid climates the floristic shift is not restricted to o.ne from SwaZZenochZoa - bamboo paramo to Calamagrostis-bunchgrass p~ramo. With lower humidity, xeromorphy increases too, and this is floristically expressed by the presence of bunches of Festuca and tufts of Stipa, DissantheZium etc. In puna grassland, there are also more xeromorphic species of CaZamagros tis sect. Deyeuxia (Tovar Serpa 1973; Gutte & Gutte 1976; Ruthsatz 1977). Extremely dry paramo grassland with. Cortaderia niti da and Sti pa is described from the Paramo de Batall6n in the Venezuelan Andes by Vareschi (1980), whereas Harling (1979) reported dry St ipa paramos from southern Ecuador. Van Geel & Van der Hammen (1973) even referred to arid paramos in the vicinity of the Lake Fuquene about 21,000-14,000 BP. The vegetation with spaced grass bunches in the lowermost part of the paramo belt is frequently caused by intensive grazing of cattle and burning by man. The effect of human activities can be noticed in these dry paramos. In the upper grass paramos, spacing of bunches is a natural feature, mainly caused by physiographical and edaphical factors. Soils are very thin, with stony patches, rocks and boulders. Indications of solifluction become more frequent towards the superparamo. At the same time the amount of water available for the vegetation gradually diminishes. Growth forms and leaf size s Growth forms of zonal and azonal communities are also related to elevation and climate. Fig. 6 shows in a schematic way the optimal development of prominent paramo growth forms for the dry and humid side of the Colombian Cordillera Oriental, as indicated by the various environmental conditions on both sides of the Sierra Nevada del Cocuy. As for the altitudinal belts, an asymmetrical

205 distribution can be noticed for growth forms (bamboos, bunchgrasses, rosettes) in zonal paramo vegetation. This may be explained as response to different climatic conditions. With regard to leaf sizes (Fig. 86), the zonal shrub paramo is determined by nanophyllous and microphyllous shrub. On the humid side of the mountains predominates a microphyllous shrub paramo. In the dwarfshrub paramo on the dry side of the Cordillera dominate bryophyllous rubiaceous species, whereas leptophyllous and/or nanophyllous dwarfshrubs are components of this zone in the wet bamboo paramos. Tussocks with revolute microphyllous leaves are characteristic for the bunchgrass paramo, but they are largely replaced by dwarfed microphyllous bamboos in humid and wet paramos. In the upper grass paramo the revolute-leaved tussocks are also prominent, but the bunches are more widely spaced. Zonal lower superparamo bush (Loricarietum compZanatae) is imbricate leptophyllous, or even bryophyllous. Nanophyllous and leptophyllous zonal superparamo vegetation is found on the dry side of the mountains. Within the reaches of the upper condensation zone on the humid side of the Cordillera, leptophyllous Loricaria are found, as well as an abundant bryophyllous vegetation of Bryophyta together with many mesophyllous plant species, e.g. Senecio canescens, VaZeriana pZantaginea, Lupinus aZopecuroides, EspeZetia cZeefii and E. Zopezii. Microphyllous Senecio niveo-aureus is also prominent here. Most of these species are covered with a dense indumentum. Phytogeography As to the phytogeographical relationships of paramo vegetation the following general conclusions may be drawn, based on dominant or prominent genera and species. For a more comprehensive review, see Van der Hammen & Cleef, in press. At the generic level, most of the associations and communities are made up of the wide temperate elements, especially in the upper part of the paramo belt. The neotropical (-Andean) element is mainly represented in the upper condensation belt (Loricarietum compZanatae), in most short grass of herbaceous meadows and in the Distichia cushion bogs. The paramo element is common in the Aragoetum abietinae, which,unlike the communities of the Swallenochloa bamboo paramo, has a limited distribution. Purely austral-antarctic (e.g. PhiZonoto-Isotachidetum) or holarctic (e.g. Myricetum) communities are rare. The wide-tropical element is only represented in the lower paramo, e.g. Xyris bog, Cyperus reedswamp. Most associations and communities are endemic to the paramos . Several of them are also present (or may be expected so) in the Puna of Peru and Bolivia, e.g. Isoetetum

andicoZae, I. glaciaZis, I. socia路 , TiZZaeetum paZudosa, Potameto-MyriophyZlion eZatinoides, Philonoto-Isotachidetum serruZatae, the Oritrophio-Wernerietum pygmaeae, the cushion bogs of the Gentiano-Oritrophion (provJ, Hypericum Zaricifolium shrub, Escallonia myrtilloides dwarfforest, the LorenzochZoetum, the Aciachnion (prov), the Muhlenbergietum fastigiatae, the communities with Lachemilla pinnata and AzorelZa multifida, and probably zonal Pernettya prostrata-Luzula racemosa moraine vegetation.Wide-temperate communities are scarce and mainly aquatic, e.g. the Dendrocryphaeo-Platyhypnidietum ripariodes, the EZeocharis acicularis community and the Lemno-Azolletum filicuZoides. In general, it seems that paramo waterbodies were first colonized by southern immigrants, long before the Panamanian isthmus came into being possibly about 2.5. millions years B.P. according to Raven & Axelrod (1974).

206

ZONAL PARAMO VEGETATION A number of factors determine the distribution and t he floristic composition of zonal paramo plant communities in the study area. The general zonation of the paramo vegetation has different altitudinal sequences for the humid and the dry sides of the mountains (chapter II). The climate is primarily responsible for differences in physiognomy and floristics. The temperature, principally the minima (and their frequency), controls the vertical distribution of the zonal communities (Fig. 82), which on the dry side of the Sierra Nevada del Cocuy (e.g. communities 2, 5, 19, 21a, 22) have markedly shifted up路slope compared to the situation elsewhere; this is to be attributed to ascending warm air from the adjacent inter-andean dry Chicamocha valley. The concept of zonal vegetation according to Mueller Dombois & Ellenberg (1974), following Walter (1954), is taken in a rather wide sense. Consequently, zonal habitats may be controlled by various primary physiographic conditions. In addition, secondary factors, e.g. the shape of slopes (concave of convex), the thickness of the soil, the drainage conditions, affect the habitats (Figs. 79, 84). Similarly, on a dry slope, mesic habitats may be present at the lower part of the slope and grade into xeric habitats at the higher part (Figs. 79, 83). This type of gradient causes differences in floristic composition and vegetation structure, and thus different zonal plant communities. Under a similar or comparable physiographic setting on slopes from the upper forest line up to the snowcap, a number of altitudinally vicariant zonal communities may be developed. On the other hand, climatologically vicarlant communities may be found in the same setting at about equal altitudes, either on the dry or on the humid side of the mountains. In this study the following example: different zonal communities can be seen to replace each other with increasing elevation in the most xeric settings on steep slopes on the dry side of the mountains: -Shrub paramo with Espeletiopsis (I); - Dwarfshrub of Arcytophyllum nitidum with Sporobolus lasiophyllus and

Achyrocline lehmanii (6); - Espeletiopsis- Calamagrostis effusa lower bunchgrass paramo (14), and - Espeletiopsis - Calamagrostis effusa upper bunchgrass paramo (19). In the superparamo these dry habitats are occupied by the Loricarietum complanatae pernettyetosum (2la) in the lower parts, and the Luzula racemosa Pernettya prostrata community in the higher parts (23). In these habitats the humid zonal soils are thin (Fig. 84) and the Ph ranges from 4.5 in the shrub paramo, to 5.3 in the upper bunchgrass paramo and to 5.8 ne a r the upper vegetation line (Fig. 85). On the same eastern s i de of the Cordillera there are mesic parts which support with increasing altitude respectively: - Arcytophyllum nitidum dwarfshrub with Diplostephium phylicoides (7) Espeletia argentea/E. boyacensis (17), - Oreobolus obtusangulus ssp. rubrovaginatus - Calamagrostis effusa lower bunchgrass paramo (16a), and probably - Espeletia- Calamagrostis effusa upper bunchgrass paramo (20). Here, the average thickness of humic zonal soil varies from about 10 em in the upper bunchgrass paramo to about SO em (45 - 55 em) in the lower paramo (Fig. 84); the pH of the topsoil is 4. I - 4.8 (Fig. 85). The difference in pH range between the strongly acid mesic and the moderately acid xeric sequences may be explained by the effect of the bedrock, which is directly underlying the xeric s equences, whereas mesic sequences are found on accumulated material with a high

207 organic content (F i g. 84). Vicariant zonal paramo plant communities along a climatic gradient are for example the two subassociations of the Loricarietum compZanatae (21), as well as the two upper bunchgrass communities (19, 20), and at about 3500- 3700 m the CaZamagrostis effusa lowe~ bunchgrass paramo with OreoboZus and CastrateZZa (IS) and the Rhynchospora paramorum- OreoboZus - SwaZZenochZoa paramo (12 p.p.). Vicariism of EspeZetia and EspeZetiopsis is expressed geographically, altitudinally and climatologically. It is expe c t ed that a large number of geographical races of associations may be described after a detailed synsystematical treatment of the zonal communities. In an earlier paper (Cleef 1978, Fig. 4) the present author presented an example of the geographical, climatological and altitudinal distribution of 12 different species of EspeZetia and EspeZetiopsis in a 75 km cross-section through the study area near Duitama and Sogamoso . In that study major habitat conditions (wet, humid, dry) for each species were indicated. At the species level a distinct conspicuous vicariism of the Espeletiinae is found in the northern part of the study area. Particular altitudinal, climatic and ecological preferenc es of the different genera of this subtribe are shown in various figures of this study (e.g. Figs . 14, 27, 28, 75, 78). Some general conclusions follow in r egard to the phytogeographic position of the zonal paramo vegetation of the Colombian Cordillera Oriental. Zonal ericaceous, melastomataceous and composite shrubs are characteristi c for the lowermost part of the paramo belt , whereas zonal rubiaceous dwarfshrub (ArcytophyZ Zum nititum ) and dwarfed bamboo (SwaZZenochZoa ) vegetation of the paramo are unique for the neotropical high mount ains . Bunchgrass vegetation, similar to that des cr ibed is characteristic for many tropical high mountains and other humid cool t emperate regions of the southern hemisphere (Cleef 1978) . Zonal bunchgrass vegetat ion is present as far north as the high Mexican volcanoes. Cyperaceae (e.g. Kobresia spp ., Carex spp.), which may determine the composition and phy siognomy of the zonal plant cover in the alpine belts of the Holarctic, are represented to a lesser degree in the zonal paramo vegetation, although Rhynchospora paramorum and OreoboZus obtusanguZus ssp. rubro-vaginatus are important diagnostic cyperaceous species and some other cyperaceous species (of Carex and Rhynchospora) are common in the study area. The zonal superparamo of the study area is mainl y det e rmined by temperat e elements, e.g. LuzuZa, Draba, VaZeriana, Senecio, Erigeron and Pernettya. The local tropica l element is scarce. VaZeriana and Erigeron are definit ely holarct ic immigrants, and Pernettya repres ents the austral-antarctic element up to the nival belt.

AZONAL PARAMO VEGETATION The altitudinal distribution and the pH range of the toplayer of the substrates of the various azonal paramo communities are given in Figs . 87 and 88. The submerged路 communities in paramo lakes (Fig. 41) more or less fit in some of the phytosociological classes described from the Holarctic: e.g. Isoetetea Br. Bl. 1937 and Potametea R.Tx. & Preising 1942. Charetea Krausch 1964 are supposedly present in the deepest parts of the lakes , but no releves have been made. The LimoseZZetea, provisionally described here from pond and lake shore habitats , is vicariant with the Litore ZZetea Br. Bl. &. R. Tx. 1943 em. Den Hartog & Segal 1964 , described from the northern hemisphere and the LitoreZZetea australis (prov.) Oberdorfer 1960 from Chile . Fig. 89 shows the altitudinal ranges of the submerged syntaxa in the study area and .as a comparison in the

208

Bolivian Andes , as based on herbarium specimens and literature data (e . g . Collot 1980) . The Bolivian communities reach to considerably higher elevations, because here the lower limit of the nival belt is located at 5400 m, whereas in our study area this limit lies at 4800 m. The vertical shift from predominance of the Isoetetea to predominance of the Potametea, noticed from high paramos towards lower areas, finds its parallel in the pollendiagram Laguna de Fuquene II (Van Geel & Vander Hammen 1973) . This pollendiagram revealed, that during the Late Glacial between about 13 , 000 and 10 , 000 years B. P . the Fuquene lake area (about 2600 m) underwent a change from cold paramo conditions to the present-day cool conditions of the Andean forest belt , and that Potamogeton replaced Myriophyllum (elatinoides) and Isoetes . The Ditricho-Is oet ian includes the Isoetetum karstenii and the Isoetetum sociae, which are pioneer communities on gravelly and sandy substrates in superparamo lakes. (Fig . . 87) .he syntaxa and communities of this alliance in the study area have been arranged according to altitude and substrate . The 1soetetum lechleri Gutte 1980 from Central Peru (4500-4900 m) is vicarious with the Isoetetum palmeri and the Isoetetum c leefii. The quillwort species,after which these associations are named , are closely related (Fuchs 1981a, b) .. The Isoetetum cleefii is thus far the only association of this alliance endemic to the study area . The Isoetetum andicolae is a unique isoetid cushionplant vegetation along the mineral clayey and sandy beaches of paramo and puna lakes . In the Peruvian puna this association is apparently transitional to cushion bogs of the Isoeto andicolae-Distichietum muscoides Gutte 1980 corr . Cleef . This sequential series of zonation has not yet been observed in the Colombian paramos, but it is quite possible, that it does occur there . The Limoselletea are dominated by callitrichids and isoetids : e . g . Tillaea paludosa and/or LimoselZa australis . The Isoetetum sociae is a pioneer association , altitudinally vicariant with the TiUaeetum paludosae and the communit-ies of Limosella australis . Fig . 91a shows the vertical distribution of these tiny amphibious communities and Fig . 91b their correlation with the various substrates in the area . Limosella australis dominated communities are rare in our area, but common at 4150 m in the Parque Los Nevados, Colombian Cordillera Central, from where a well - defined association may be described . Prominent species in both alliances comprising the submerged and amphibious vegetation of paramo lakes and ponds , have strong austral-antarctic affinities , and they must have been present already in paramo water bodies shortly after these biota developed (Vander Hammen & Cleef , in press). The Potameto-Myriophyllion elatinoides (prov . ) as yet based on as few phytosociological records only , is the highest located alliance in the northern Andes, and mainly consists of elodeids and/or myriophyllids . Lower down it is replaced e . g . by the Myriophyl Zo-Potamion illinoiensis Rangel & Aguirre (in press) described from Lake Tota at about 3000 m (Boyaca) . Elodeids are predominant there . Myriophyllum elatinoides and M. brasiliensis are diagnostic species, the latter with a low cover . Pure stands of Myriophyllum elatinoides can be observed in lakes and streams reaching up al!Jlost to the lower superparamo in the Colombian Andes and these myriophyllid phytocoena are supposed to represent a fragment of communities with Myriophyllum in the lower part of the paramo belt . The HydrocotyloMyriophyZletum elatinoides is present along the unstable shores of peat-bottomed paramo lakes , where a hydroseral zonation can be noticed with mire communities of the Calamagrostion ligulatae (Fig . 42, 49 , 51) . Species of Potamogeton are apparently absent where the average annual temperature is lower than 5째C . Potamogeton berteroanus seems the highest located species up to 4000 m. Its distichous , lanceolate to linear (nanophyllous) leaves suggest a strongly specialized way of life . In lower places Potamogeton asplundii is common in bamboo paramo lakes and the euryoicous P. illinoiensis may locally be present

209 also. The latter two Potamogeton species are characteristic for the Myriophyllo-Potamion illionoiensis Rangel & Aguirre (in press) of lakes in the Andean forest belt. Elodea has not been observed in paramo lakes in the study area. More releves on different substrates at various altitudes are needed, however, for a more solid phytosociological basis and a further subdivision of the Potameto-Myriophyllion elatinoides.

Eleocharis reedswamp communities are present from warm tropical lowland (J.W. Bristow, unpubl. list; Lindeman 1953) up to about 4000 min the Colombian Andes, but are absent in the superparamo. The Eleocharitetum macrostachyae and the Elatino-Juncetum ecuadoriensis have the same horizontal and vertical distribution in the study area, but they are markedly different in floristic composition and ecology (Fig. 87). Eleocharis macrostachya reedswamp borders eutrophic paramo lakes. Juncus ecuadoriensis is conspicuous in or along mesotrophic small lakes or pools with a peaty floor and partly or completely surrounded by Sphagnum bog. Eleocharis macrostachya is widely distributed in temperate America; Juncus ecuadoriensis, however, is restricted to the northern Andean paramos (Balslev 1979). The Junco ecuadoriensis- Eleocharition macrostachyae apparently belongs to a not yet described new tropical Andean order. Reedswamp and mire vegetation together are comprised in the MarchantioEpilobietalia. This order has floristic affinities with the ScheuchzerioCaricetea fuscae Tx. 1937 and the Montio -Cardaminetea Br.Bl. & R.Tx. 1943 but most likely it belongs to an undescribed tropical Andean class. The tall sedge associations of the Galio-Gratiolion are generally supposed to occur throughout the north Andean par~mos as well as in open azonal habitats in the adjacent Andean forest belt, but they seem to be absent in the superparamo. Ecologically, they are in many respect reminiscent of the Magnocaricion W. Koch 1926 from the temperate northern hemisphere. The Magnocaricion belongs to the Phragmitetea R.Tx. & Pr.. l942, but in the northern Andes this syntaxon does not occur. Phragmites australis (Cav.) Trin. & Stend. seems almost absent in tropical S. America except for few stands described e.g. from Peru (Koepcke 1961; Muller & Muller 1974)). Communities and associations of the Galio-GratioUon mainly thrive on moderately to weakly acid clayey soils which are rich in organis matter (Fig. 87). Of its associations, the Senecionetum reissiani has a limited distribution and requires a more stable habitat; the Caricetum pichinchensis and the Cyperetum lagunetto grow on soils with widely different pH's. This is not surprising, since both species easily colonize azonal wet habitats. The same is true for the Geranio-Calamagrostietum liguZctae, found in Sphagnum bog as well as in lakeshore habitats. Grass mire vegetation is extremely rich in gradients, and as a result rapidly changes in floristic composition,forming a fine-grained mosaic of a fairly large number of communities recognized in this study. Calamagrostis liguZata is well represented in different types of . open wet paramo habitats: e.g. beaches of superparamo lakes, flooded flat depressions along streams, unstable turf in the paramo lake hydrosere. In contrast, the Carex acutata community roots onl y in compact turf along lake shores. Calamagrostis ligulata mire is optimally developed under slightly acid conditions, which implies a continuous influx of eutrophic water from adjacent higher areas or from lakes. In the hydroseral environment usually this grass mire forms a contact community with several other vegetationtypes due to the diversity in environmental gradients in this habitat: e.g. Carex acutata community, Caricetum pichinchensis, Diplostephietum revoZuti, OritrophioWernerietum pygmaeae, (SwallenochZoa-) Sphagnum bog and towards open water the Potameto-Myriophyllion elatinoides (Fig. 42, 50, 51). With increasing acidity some Calamagrostis ligulata stands may develop into Sphagnum bog (Fig. 42, 50). Pioneer communities of the Marchantio-Epilobietalia in extreme habitats are poor

210 in species: e .g. the Carex acutata community, the CaZamagrosti s ZiguZata superpararno community, and the DrepanocZadus aduncus-CaZamagrostis ZiguZata community of calcareous mires. Wet flush vegetation in the study area belong to the Wernerietea. Here, two associations are des c ribed, one of which, the Carici- Werne r ietum crassae, is endemic, and mainly r es tricted to high locations in the Sierra Nevada del Cocuy. The other, the Oritrophio- Wernerietum pygmaeae, is widely distributed vertically and horizontally (Fig. 87). Rhizomatous creeping, chamaephytic composites (Werneria, Senecioneae) are in tropical Andean flush vegetation, so that these communities are floristically unique among the other flush communities of vascular plants in the world with e.g . Cruciferae, Cyperaceae, Rosaceae. Werneria becomes less conspicuous on moss turf. The development may start with filamentoup algae and/or liverworts (Riccardia, sp., Isotachis serruZata) growing in a dense submerged moss layer in the Carici- Werne rietum crassae. Emerged thi ck CampyZopus c f. incertu s turf or hummocks of the FZoscaZdasioDistichietum ma rk the disappearance of the Wernerion crassae-pygmaeae at thes e heights. The Oritrophio- Wernerietum pygmaeae is often dominated by a single spec ies of aquatic mosses, e.g . sphagnum cycZophyZZum, Scorpidium scorpioides or DrepanocZadus exannuZatus in th e lower superpararno and the (upper part of) the grass pararno in the study area. Low ros e tT~s of composites or low sedges generally replace these aquatic mosses in the lower part of the paramo belt. These wet flush communities are generally surrounded by a small .belt of the MuhZenbergietum fastigiatae, a syntax on which occupies the gradient from wet to dry and which is characterized by its low, bluish, soft hummo cks of grarninoids. Floristically, this is an intermediate association between different syntaxa and communities: e.g. the CaZamagr ostion ZiguZatae, Werne~;etea, spaghnum bog communities, the Aciachnetum and the humid and dry zonal vegetation (Fig~ 27, 75). Succession of the Wernerion crassae- pygmaeae leads to the mire of the CaZam~grostion ZiguZatae and/or to hard hummock bogs of the Gentiano- Oritrophion (prov.), whi ch are dis cussed below. Bogs are common throughout the pararno belt and consist of peat mosses

(sphagnum spp.) in the lower pararnos and cushions of vascular plants (dicots re sp. rnonocots) in the higher pararnos (Fig. 6, 87). Paramo bogs thus belong to t wo essentially different s yntax onorni c groups : I) Wernerietea, comprising the compac t vascular cushion bogs, 2) Sphagnum bogs (Sphagneta), whi ch inc lud e al l Sphagnum bogs in the pararno . At 3600- 3700 rn these bogs are in contac t and frequently intermixed. The FZoscaZdasio- Distichietum is hardly or never a contact community of Sphagnum bog (Fig. 87). A hummock-hollow relie f , known fr om bogs in other parts of the wo rld , is characteristic for both t ypes of pararno bogs. The vascular cushion bogs in the study area are phys iognomically and f lo ristically tropical andean and austral-antarctic in distribution (Cleef 197 8). Sphggnum bogs are basically wide-temperate, and occur in cool and humid climates throughout the world, a lthough the pararno Sphagnum bogs are characterized by a number of local tropical elements. It is remarkable that the (az onal) pararno bogs have their lower limit slightly be low that of the corresponding z onal pararno vegetation. This may be explained by the colder environment of pararno bog compared to the prevailing environment on the surrounding slopes. The mean year isotherrnes that control the vertica l distribution of zonal vegetation in the pararnos are supposed to run through pararno bogs considerably farther downslope . In boggy depressions cold air co llects at night, as was demonstrated in Ecuadorian and Venezuelan pararnos by resp. 0llgaard & Balslev ( 1979) and Hedberg & Hedberg (1979), who showed that at 5 ern above ground the temp e r a tures were f luctuating max imally . This temperature minimum is also reflected by the preponderance of low rosettes and leptophyllous species in this

21 J

habitat. Floristics, phytogeography , distribution and ecology of cushion bogs of vascular plants in the Colombian paramos were discussed before (Cleef 1978). It was demonstrated that they are austral-antarctic in origin, composition and physiognomy. They are present as soli~enous bogs or floating at the surface of glacial lakes. Oreobolus cushion bogs were reported as new to the paramo belt, where they occur together with the Hyperico-Plantaginetum rigidae. They were also found on decayed Distichia bog at 4350 m in the Sierra Nevada del Cocuy. The Oreobolus hummock bogs have a limited distribution in the study area and are supposed to be interrelated with certain phases in the succession towards the Hyperico- Plantaginetum rigidae and the Floscaldasio-Distichietum. Under similar climatical conditions these bogs probably return again to the original floristic composition, either or not v ia an Oreobolus phase. The pH records of the peaty top layer under the three types of paramo cushion bogs show that the Floscaldasio- Distichietum prefers a moderately to weakly acid substrate, the Hyperico- Plantaginetum rigidae a moderately acid substrate and the pH of the substrate under the 01>itrophio-Oreoboletum is intermediate (Fig. 87). Decay of the hummocks often begins with the establishment of "epiphytic" vnscular plants, but in wet climates usually proceeds with that of mosses (e.g. Breutelia

allionii, Campylopus cavifolius).Lichens (Oropogon lo~ense, Cladonia spp.) appear together with dwarfshrubs (Hypericvm lancio-ides, Pernettya prostrata, Disterigma empetrifolium)towards the end of the succession. The Hyperico- Plantiginetum and the Floscaldasio-Distichietum (Fig. 87) each have distinct vertical range. Near 4000-4200 m, they may occur together forming mosaics completely covering the valleys. This was also observed in the Parque Los Nevados (4000-4300 m) in the Colombian Cordillera Central (Cleef et al.in press), and according to Gutte (1980) this is common between 4200 and 4700 min the high Central Peruvian Andes. The vascular hummock bogs of the study area consist of leptophyllous, pulvinate chamaephytes, showing definit e tendencies upslope towards xeromorphy. Comparing growthform and leaf characteristics of resp. Plantago rigida, Oreobolus obtusangulus and Distichia muscoides the following is noticed: 1) hummocks become more compact towards higher altitudes; 2) ':: he small Plantago rosettes have indumented leaves parallel with the surface of the bos . The small blades of Oreobolus are set close to the stem under an angle of 30째) those of Distichia are almost imbricat e and both are without indumentum; 3) Diminishing size of the leaves with height and toge th er with increasing size of the sheats, which become graduall y more amplexicaulous. Petioles are pres ent in Plant ago rigi da but absent in the t\VO other species; 4) Rounded or blunt leaftips of Plantago rigida contrast with pointed dark leaf tip s of Oreobolus and Distichia; 5) Coriaceous leaves in Plantago rigida contrast with sclerophyllous leaves in the two oth~r species. . 6) Flat leaf surfaces of Plantaqo riqida differ from the slightly more plicate of Oreobolus to the completely plicate leaflets with a sharp keel of Distichia; 7) The symmetrical rosettes of Plantago rigida are replaced by bilateral compressed rosettes of Distichia muscoides at higher altitudes. Weberbauer ( 1911) and Raub ( 1939) provided excellent line-drawings of the species discussed. For the time being the cushion bogs of the study area are provisional l y assigned to the Gentiano-Oritrophion and the Wernerietea. It cannot be ruled out that future classifications, based on additional data, rank the hummock and hollow communities as separate classes, as in European Sphagnum bogs . Paramo Sphagnum bogs occur in the lower part of the paramo belt. Owing to the relatively climate, Sphagnum bogs occupy a minor part of the paramo landscape in the bunchgrass paramo. Their trophic levels range from weakly acid

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(EspeZetia- BZechnum community; SwaZZenochZoa-Sphagnum community) to moderately acid (other Sphagnum communities)(Fig. 87). Their upper limit coincides with the lower limit of the cushion bogs. Some basically different Sphagnum communi ties were recognized which may be further subdivided . The SwaZZenochZoa-BreuteZia-Sphagnum slope bog also belongs to the Sphagneta; it is transitionel to zonal bamboo-(bunchgrass) paramo. This slope bog is floristically and ecologically closely related to the SwaZZenochZoa-Sphagnum valley bog community and. the giant Puya~Sphagnum community, and may be considered as a special type of"blanketbog"-vegetation restricted to the (continental) humid equatorial high mountains. The slope bogs, however, considered true blanketbogs in the sense of those described e.g. from oceanic Ir eland, because they also depend on watersupp l y from neighbouring slopes. These bogs are absent in the drier bunchgrass paramos. The Aragoetum abietinae puyetosum is a shrubby climax community on XyrisSphagnum bog and the DipZostephietum revoZuti marks the end of the succession on Sphagnum bogs with Xyris, OreoboZus and GentianeZZa cerymbosa and giant Puya-Sphagnum bog. Most (dwarf) shrub species in paramo Sphagnum bogs are leptophyllous. Dense , usually tall EspeZetia stands are also frequently noted successional to soligenous Sphagnum bogs covering small wet peaty ground along paramo streams. Probably only a small part of the Sphagnum bogs in the study area may represent true raised bogs, as ombrotrophic Sphagnum growth is restricted to the central part of the largest bogs, especially, the Xyris-acutifoZia-CampyZopus cucuZZatifoZius- Sphagnum-bog (7oaa) in the bunchgrass paramo. A lower precipitation causes a lesser runoff here. Most Sphagnum bogs are in direct contact wi th mineral soil or th ey are supplied with water from mineral soils. The latter explains the high pH values, e.g. in SwaZZenochZoa-Sphagnum bogs. The runoff under humid paramo conditions is markedly higher than under dry conditions. Better drainage, enriched phreatic water and some decomposition apparently put a limit to the presence of ombrotrophic Sphagnum peat in the bamboo paramos, even though Sphagnum bogs are common. Among the IS Sphagnum species listed by Griffin (in press) for the Colombian and Venezuelan Andes, only S. paZustre is absent from the paramo belt, whereas S. meridense just reaches this belt. Sphagum cuspidatum, S. mageZZanicum, S. o:r:yphyUum and S. sancto-josephense are the most common species in the Sphagnum bogs of our area. The first two species are wide temperate or subcosmopolitic in distribution ; the last two are n eotropical but may have originated from wide temperate ancestors (Crum & Crosby, 1974). Sphagnum cycZophyZZum and S. pyZaesii are holarctic immigrants. Their ecology is quite different from that of other peat-mosses. S. cycZophyZZum is common in the Wernerietea, and S. pyZaesii is a rare species in high locat ed paramo lakes. As to the phytogeographic composition of the Sphagnum bogs in the study area, it may be noted that pres ence and cover of (neo-)tropical genera increase towards lower areas, e.g. EspeZetia, Puya, DipZostephium, SwaZZenochZoa, Aragoa, ArcytophyZZum (muticum), Xyris. The austral-antarctic element is represented by OreoboZus, Pernettya, CZadia, MyrteoZa, Rhacocarpus. Originating from southern immigrant taxa are: Laestadia, DipZostephium, Aragia, BreuteZia, BZechnum Zoxense and Lepidozia/Kurzia, Oritrophium, Distachia (Cuatrecasas 1969 ; Vander Hammen & Cleef, in press). From holarctic stock or origin are PZeurozium schreberi, TeZaranea nematodes, Geranium multiceps, Bartsia spp., HaZenia spp ., Gentiana_sedifoZia and the Sphagnum spec ies mentioned ear lier . Some species are restricted to cushion-bogs (Gentiano-Oritrophion), e.g. Hypericum Zancioides, Bartsia spp., Nertera granadensis, Pernettya prostrata, BreuteZia spp., Rhacocarpus purpurascens, Werneria humiZis, and Gentiana sedifoZia. Species of LachemiZZa are nearly absent in well-developed Sphagnum bogs.

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In sum , cushion bogs and Sphagnum bogs are altitudinally vicariant, and floristically quite different. They have only got a few species in common. The hummock-hollow relief as known from other bogs in the world is well developed. Most bogs are soligenous, but they may cover open surfaces of former glacial lakes. The tropical element is conspicuous, and increasingly represented in Sphagnum bogs at lower elevations. The austral-antarctic element seems stronger represented here than the holarctic one. Species of Breute lia have a gradually higher cover towards higher altitudes, where they replace Sphagnum, which is almost absent in cushion bogs. Xeromorphy in cushionbogs increases with altitude. The most striking aspect of the azonal shrub and dwarfforest vegetation in the study area is the large number of thicket communities dominated by one single species, generally of the Compositae or Hypericaceae. In a few communities , the following families may be dominant: Scrophulariaceae (Aragoa), Rubiaceae (Arcytophyllum), Myricaceae (Myrica ) , Escalloniaceae (Escallonia) and Rosaceae (Polylepis, Hesperomeles). Noteworthy is the absence of dominant Ericaceae and Melastomataceae in azonal thickets, but they are common or dominant in zonal communities of the subparamo. Woody formations of nanophyllous species of Compositae (Diplostephium, Senecio, Gynoxys ) are most common . In more xeric habitats or at higher altitudes there is a tendency towards leptophyllous shrubs . Microphyllous, woody formati ons are mainl y found on the humid side of the Cordillera . Practically all paramo species of Hypericum are leptophyllous; some of them, native to the most humid paramos, are nanophyllous . These are nearly absent in the superparamo, except Hypericum lancioides, which may be present in Dis tichia bogs, and H. selaginoides, in the lowermost zonal superparamo. Rosaceous thickets are rare in the study area, but rosaceous dwarfforests are still common, although they are endangered by human activities . The same is true for Hesper omeles cf. goudotiana dwarfforest , the groundlayers of which have largely been converted into meadows for cattle. Polylepis quadrijuga is the only woody species in the paramo belt with compound mainly on the dry side of the leaves. In the Andean and Subandean forestbelt, mountains , woody species with compound leaves are often dominant: e.g. pinnateleaved species of Weinmannia (Cunoniaceae) and Brunellia (Brune lliaceae) , and further species of Inga (Caesalpiniaceae), all of which belong to the order Rosales. Members of the Rosales are in fact the main constituents of the canopies of the zonal high Andean forests, except the Quercus woodlands. In contr as t, simple-leaved species of Weinmannia and Brunellia sect. Simplicifolia Cuatr. are dominant in the upper stratum of Andean forests on the opposite , humid side of the mountains. Even palms, e.g. Geonoma weberbaueri, Givnish (1978)referred especially to wet mountain forest when he concluded that compound leaves are more common in tropical lowland rain forest than in montane or elfin forest. From the remaining thicket genera, Aragoa, Escallonia and Polylepis show austral-antarctic affinities beyond the genus level Myrica i s a holarctic genus, and Arcytophyllum and Hesperomeles seem to be immigvants from the northern part of Central America. All the mentioned woody species occur optimally in azonal habitats, and their (present) distribution is determined by a number of factors. Humid to wet and boggy habitats contain the Diplostephietum revoluti, the Aragoetum abietinae, the Senecionetum andicolae, the Senecionetum reissiani, the Hypericetum laricifolii , and some dwarfforest and/or (dwarf) shrub communities with Escallonia myrtilloides , Senecio cacaosensis , and Hypericum magniflorum. Mesic habitats are occupied e.g. by the Senecionetum nitidi, Senecionetum vernicosi, Hypericum spp. shrub, the Myricetum parvifoliae,

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the Senecionetum f lo s-fragr anti s and Senecio vaccini oides shrub (in pocket s in the Paramo de Guantiva). Well-drained habitats (rockshelters, screes, rocky exposed peaks and ridges) contain e.g. the Cor taderi o-Ar cytophylletum caracasani , dwarfforests of Gynoxys albives t i t a, Polylepis quadri j uga, and Diplostephium rhomboi da le , and e.g. (dwarf) shrub of Diplostephium gluti nosum,

D. coZombianum, D. juaji bioyi.

The azonal dwarfforest and shrub communities apparently belong to several different not yet described syntaxa. Because of the constant and favourable humidity and shade conditions, some of these communLtLes have species in common with the zonal upper Andean for est or with paramo bogs, especiall y species of the understorey (see table 14). As to structural and textural characteristics, four different layers can be observed in paramo dwarfforests; I) an almost closed groundlayer of bryophytes and low herbs, 2) an open or c losed herb-dwarfshrub layer, 3) an open or closed shrub layer. Bamboos, if present, usuall y r e ach up into this layer, and 4) an open or closed dwarftree layer, generally not higher than 8 m, only in dwarfforests. Most leaves are sclerophyllous, and some are coriaceous. The latter catagory is proportinally higher represented on the dry side of the mountains. Most of the dominant woody species are nanophyllous, and sma ller numbers are leptophyllous and microphyllous. Mesophyllous species are absent. This is in general agreement with Cuatrecasas (1934), who based his findings, however, on all woody species present in the paramo belt of the areas studied in the Cordillera Oriental and Central of Colombia. The azonal dwarfforests in the study area are dominated by nanophyllous and microphyllous species. Leptophyllous groves are practically absent. Wooded species on the humid side of the mountains generally tend to larger leaf surfaces. According to the revised Raunkiaer scale (see Werger & Ellenbroek 1978) all Hy pericum shrub is leptophyllous and only a few of Raunkiaer's microphyllous species are (sub-)nanophyllous . If Barkman's category bryophyllous (previously also applied by Vareschi 1966) for the small leaf surfaces up to 4 mm2 is applied, then the most hypericaceous and all rubiaceous (zonal & azonal Arcy t ophyllum) shrub belongs to this leaf-size class. The Ar agoetum abietinae , with average leaf surfaces of about 5 mm2 , is somewhat intermediate between bryophyllous and leptophyllous. It thus appears, that the general trend for leaves of azonal paramo shrub is nanophyllous, followed by leptophyllous resp. microphyllous . The azonal meadow communities of the paramo consist of short grasses of the xerophytic Stipeae or of low ros a ceous herbs (Lachemilla, Acaena ). The Lor enzochloetum (Stipeae)and Agros tie tum f oliatae are the only communities with low bunches or stiff tufts. All the mentioned species become dominant in azonal habitats, which have in common a concave physiography, thick soils, and high soil humidity. Lorenzochloa is an euryoicous species present form the forest line up to the superparamo line. This corresponds to data from the Venezuelan paramos (Farinas, 1979). The Aci achnetum is common in dry paramos in the northern part of the study area. The original description from Venezuela by Va reschi (1953) is emended here with floristic data from the Colombian Cordillera Oriental and Central.In view of its wide distribution along the tropical high Andes , it is supposed that a number of regional associations dominated by the monotypic Aciachne will be recognized that might be combined into an Aciachni on pulvinatae (prov.). The Acaulimalva- Agr ostis br eviculmus community (25) of higher altitudes (4000-4300 m) is a floristically and ecologically related community and its position amongst the zonal communities in this study is a provisional one. The Muhlenber gietum

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fastigiatae similarly has a wide tropical Andean distribution and is restricted to wet valley floors in the transition to the flush vegetation and/or vascular cushion bogs of the Wernerietea. Rosaceous herb fields with widely distributed native species are considered as resulting from burning and/or intensive grazin by cattle. The Agrostio-Lachemilletum orbiculatae is found on flat valley floors; occasionally the roots are within reach of the phreatic level. The Agrostis b reviculmisLachemilla pinnata community replaces the Aciachnetum pulvinatae in the study area in moderately steep habitats, whereas the Acaena cylindristachya community replaces zonal Calamagrostis effusa paramo, especially in the Sierra Nevada de S. Marta and according to Vareschi (1980) in the Venezuelan paramos. As a result of intensive grazin and burning, tussocks dissapear , leaving a herbaceous mat, which locally may develop into a rosaceous herbfield. Weberbauer (1911, 1945), Rauh (1958) and Gutte & Gutte ( 1976) refered to such meadows in the Peruvian puna, where they may cover a larger area. Gutte & Gutte (1976) reported as characteristic meadow taxa from Central Peru at 3900-4800 m species of Calamagrostis, Stipa, Dissanthelium, Poa, Muhlenbergia (including M. fastigiata), Aciachne and Bromus, and herbs as Oreomyrrhis andicola, Lachemilla pinnata, Tephrocactus spp., Acaulimalva engleriana. The non-shrubby vegetation of screes and outcrops in the study area is dominated by temperate elements, which include wide ranging taxa (e.g.

Cystopteris diaphana, Polystichum, Asplenium, Senecio, Montia, Draba, Poa, Thamnolia), and taxa of originally holarctic (e.g . Valeriana, and austral-antarctic arrival (e.g. Rhacocarpus purpurascens, Racomitrium crispulum, Neuropogon spp.). Local tropical Andean genera are Kingiobryum (paramo element) and Er ythrophyllopsis. Among the most common vascular species restricted to rocks may be mentioned Echeveria spp., Elaphoglossum mathewsii, Polystichum polyphyllum, Hymenophyllum trichophyllum, and other polypodiaceous ferns. At present only a few records of epilithic communities in the Colombian Andes are available, and none for the floristically very rich non-vascular epiphytic communities and synusia. Future research The classification of the zonal vegetation, Sphagnum bogs and other still unranked communities remains a future target. Provisional tables are already available. Forthcoming studies shou l d include synoptic tables and analyses of phytogeography, structure and texture of the paramo vegetation . Mapping projects of some areas of paramo vegetation are in progress (De Nies & Lebouille, unpubl.; Kloosterman & Salamanca, in prep.). Various vegetation types recognized in this paper occur in this mapped area . Soils analyses should also be dealt with in detail in future studies. The relation between modern paramo vegetation and pollen influx in the study 'area is presently studied by Mrs. R.A.J. Grabandt (in prep.) . The pollen diagrams mentioned in this study from the Paramo de Sumapaz are to be published in a more defenite form in the framework of the current ECOANDES project, which is also focussed on this area (ECOANDES 1979). Preliminary notes have already been published (Vander Hammen 1979 ; Cleef, Carvajal et al., in press; Vander Hammen & Cleef, in press). The overwhelming richness of the still incompletely known flora and vegetation of the paramos of the Cordillera Oriental of Colombia made the present author realize the primary importance and necessity of taxonomic work. This applies also to bryophytes, lichens, algae and fungi, which are an important component of the paramo ecosystem. Knowledge of cryptogams is

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indispensable for vegetation studies in the paramos and in general for humid high tropical mountains. Without intensive botanical collecting and the help of many specialists the present study would have been impossible. As this study is only one of the first contributions towards a geobotanic inventory of the Colombian Cordillera Oriental, it should be realised that it is far from complete and that much work remains to be done. This type of geobotanic inventory of the recent and the study of the past neotropical plant communities and their environments, are however, the first step towards a better understanding of the present day neotropical ecosystems.

2J7

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229

APPENDIX I

Figures

Fig . I. Approximate distribution of Neotropical paramos as defined by physiognomic and floristic criteria. The distribution of the paramos in Peru and Bolivia is according to Troll (1968) and Ellenberg (1979). "Perhumid Alpine" in the sense of Ellenberg (1979) is considered as paramo. The northernmost Andean paramos are confined to altitudes above 3300-3800 m.

..•

rP.

0·

':! 0

' 10 10

- ·"- ···· 3000 m. ···-···-· 2000 m. 1000 m. 500 m. 200m. 200

zo 0

400

600

BOO 1 OOOkm

100 200 300 400 500 600 miles

100

Fig. 2. Site locations of the northern Andean paramos (including those of the study area: 13-28) . I. Cende

2. 3. 4. 5. 6. 7. 8. 9. 10. II.

12. 13. 14 . IS.

16. 17 . IS .

19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34 . 35. 36 . 37. 38. 39. 40. 41. 42. 43. 44. 45. I

Niquitao Sierra Nevada de Merida La Negra Batall6n Zumbador Sierra Nevada deS. Marta Perija Jurisdicciones/Oroque , Cachira Romeral San Urban Tama Almorzadero Sierra Nevada del Cocuy Pisva-Chi ta Tota-Vado Honda-Arnical Cordillera de los Cobardes Guantiva Rusia Tunja-Leiva-Arcabuco Neusa-S. Cayetano Gu.asca Palacio Chuza-Chingaza Farallones de Medina Cruz Verde-Chipaque Chisacii Paramo de Sumapaz with Nevada Cordillera de los路 Picachos-C. Leiva Cerro Punta Picas de los Fragua Parque Los Nevados (Rufz, S. Isabel , S. Rosa, Tolima) Nevada de Huila Macizo Colombiano (Purace) Par ami llo Frontino C. Tamana c. Tatama c. Torra Farallones de Cali Dona Juana-C. Animas Galeras Cumbal Chiles Angel

to 8 : transects study area

Buritaca- La Cumbre 1977

Parque Los Nevados ( S. lsabel -S .Rosa) 1980

Colombian Cordillera Oriental -study area-

10Ckm

Fig . 2

PALACIO- LA CALERA (3500m)

(•- 7(

ELVERJON (3250m)

NEUSA LA VIOLETA 13250 m I

(•- 4]

t• 93.1 1054

\897

PO.romode Cruz Verde

!• -l4l

REPRESA NEUSA I 2980 m I

14 -171

105• 1053

I (

a CHUZA. CUCHILLA GOLILLAS {3350ml [•-2) {•8.7'11900 CHUZA MONTEAREDONOO (3100 m I

(•-41

1"10.1"12453

E1 HI IY V ~~ Yll ~ill IX l I I Jll "'I'Q:I-ll~clurt lt~~lnl~tyor•.:t~PCI IL !IIft]

lA PRIMAVERA l 31.60 m )

PnramodESumapaz AlTO CA ICEOO (3800 m I

1"·61

PARAI<OOESUMAPAZ

1"·41 lAGU NAS DEL CHISACA (3700 ml

t• .a J

EL HATO (3150ml

t•- zn

t•9.9"J 713

t• ss"Jms

160

PAMPA GALERAS {l,!JIJOml

14-41

SOGAMOSO-lAS CINTAS (3t.83m)

1"-71

1' 79"11091

PARAMO de BERLIN I SANTANOER·t3Zl0ml

8.3• 7lO ~S:

n.o IZ - 11

m Fig. 3. Climate diagrams of various stations in the paramo and upper Andean forest belt of the study area (a-o) and an example of the Peruvian bunchgrass puna (p). For a number of stations mean annual temperature values, when calculated, are marked with an asterisk. Stations a-hare located from NW to SE in transect 5 and 6 (see Fig. 2); stations i-1 are situated in transect 7 and 8 (Fig. 2) from NNW to SSW; and stations m-o are from the northern part of the study area.

ANNUAL PRECIPITATION ( mm) AT STATIONS IN THE UPPER RIO CHUZA & RIO BLANCO VALLEYS, CUNDINAMARCA ~----------------PALACIOS, Guasca 19yr)

alt.m

3700

3600

~------------

3500

PALACIOS. El Angulo I lyr J

3400 CHUlA, Golf/las I 2 yr J .. · .

.,,,,

···'

:.: ·

3300 CHUlA, Mantes Negras I 2yr J

3200

310 0

3000

2900

~-----------------

CHUlA, Monlerredondo I 5 yr J

1-'----------------------

CHUlA.

E! Oedall3yr)

~-------------------------• 1000

2000

3000

CHUlA Campamento I 2yr J

4000 precipita t ion in mm

Fig. 4. Mean annual precipitation at stations in the upper Andean forest and th e lower part of the paramo belt at the humid side of the Cordillera E of Bogota.

t-'•CJ

~ ~

n"' 0 0

>'%j

t-'• ()Q

\.J1

"0 t-'• P> rt 11 t-'· t-'•0 (/l

0 H'l

t-'•rt

rt ::r ::rro rt <!

:TP> P> (/l rt

t-' H'IP> 11

(/l

a0"0 P>l (1) 11 P> o a rt 0 ::r

(1) H'l 11 t-' 0

11 (1) P> t-' (1) 0

(/l

H'l

(1) rt

o..::r

(1)

0 (") 0 0 t-' t-'

I 0 rt

(1)

r::r

(1) 11

t-'•

P> (") rt 0

(1) 11 p..

<! t-'• P> t-' t-'

(/l

n ro

11 t-'P>

11 0 11

H'l t-' ·

t-'(1) 0 ~ 11 rt P> P> (/l t-'

ARGENTINA: PUNA FlORA / Celrua

IJSII

(1Jrosc . fomilltSIUitCOitJiflrrrfl/

COlOHBIA : PARAHO FlORA COf/0/llfRA ORIENTAl

COlOHBIA · PARAHO FlORA COROillERA ORIENTAl

:<:

'"d

>-xj

0 ,.. . l"i CrtO

,.. . ()Q

::I

::s ::r ,... s rt Ill

Ill

,.. ...... (1)

::s

(/)

::s

rt ,... rt

rr COQ

CLI"i

,... 0

::s :<:

Ill rt >-':T N

0 0 ::I l"i

(1) (/)

Ill

::s

(/)

0 Hl

0..

(') ::r

,...

PROMINENT PAR AM 0 GROWTH FORMS

>-' (1)

sIll

'"CJ Ill\

evergreen sh rub

(1)

Ill

bunch grasses

rt l"i

,... 0

0..<! (1) (1)

!lJ()Q

bamboos

>-'(1)

,... rt N

Ill

(1) rt 0.. ,... 0

Hl::S

0 l"i

0 Hl

stem rosettes

~branched

stems

ground roset tes cushions

::Trt

(1)

;:T

(1) 0.. l"i (/)

'<:

Ill

0..

::S '<: 0..

::TI"i

(1)

s,... 0>

0.. ,...

(/)

::s

,... l"i 0.. (1) (1) ..... 0> 0 rr

Hl ,... rt

::r (1)

::s

atmospherical humidity

!S88ll

ca ndensatlanbel t -B8&J

LAGUNA LA PRIMAVERA PARAMO OE SUMAPAZ

3510m

2920 ±130 BPI 3

4700±150BPI 4

7290±130 BPI

[{::)!

(Andean) forest elements

c:J Subpciramo elements · · (Compositae. Hypericum,etc.) Grasspci ramo elements D (Gramineae) Fig. 7. Simpl ifi ed pollendiagram of the Laguna La Primavera (3510 m}, Paramo de Sumapaz, covering th e last 7500 year s.

('") '"d >i

C/l C/l

C/l ,...

0'<: I 0

"1 ,... ()Q (X)

C/l()Q

(1) ::l ('") 0

El ,...,... ;t

~PJ

(:::

NIVAL BELT

0 ('") ::l PJ t-' t-'

,... ;t

()Q ;t ::r<(:

,-.~~

;t t-'•

~::l

(1)

SUPER PARAMO

0 N t-'0

~ ~

UPPER SUPER PARAMO

,... ,...

LOWER SUPER PARAMO

UPPER GRASS PARAMO

o";t

PJ 0 ::l ::l 0

H'l

GRASS PARAMO

,...t-'(1)

P.;t

t-' Cll'O

>i PJ\ PJ >i

ll>

OEl

,...>i 0

SUBPARAMO

ro . <:

::l (1)

;t()Q

ll>

(1)

. 1i~~*' f''il: {i

Jt,.J

·- $)"' · ',-~

UPPER (DWARFSHRUB) SUB PARAMO

t-' ;t

·~Pi ,,~,I

ll>

::l

,... ::l

ll> C/l ('") ~

(1)

,...

;t ('")

UPPER ANDEAN {CLOUD) FOREST

"-i: "-t.

l,,,,

I,,,, L·"'

ILoricarietum

complanatae I

6 N

A L

s 0

I L S

ATMOSPHERlCAL HUMID SLOPE

'i.~

LOWER GRASS PARAMO

....0

~ ~/ STRUCTURE SOILS ~/

ATMOSPHERICAL DRY SLOPE

"''IW;-- upper

condensation zone

_;.!fVIV

upper limit of bamboos (Swallenochloa)

~~~

"~Vi

'~~ ~.1, M

',~,,, '%,~~v.:

~ ,,

.,,,

·~1/ timberline condensation zone with conspicuous liverwortlayer __ 111

OUl;l> t1 (ll

,.... () (ll (ll ,;- t1

!-'•Ill r;-O()Q Ill ;j (ll

'"<:! ,.... ()Q

.....

<!:>

,;- Ill

;:r,_. t1 ,;-

,....

,;-

()Q

::ro. (ll

,;-

::r (ll

(I)

atmosphericall y dry (Paramo Clincovo. Alto Volle Logunillas .)

NW alt.m

SIERRA NEVADA DEL COCUY

f alt.m

(I)

,;-

(i)

::r

(ll'Q

t1 ;j

Ill\ t1 Ill

atmospherically dry

NIVAL BELT

atmospherically humid (headwaters Q.Play6n.

Q.Osos. Rfo Casanare) 5500+------ - - - - - - - 1

0 Hl

atmospherically humid

5000

NIVAL BELT

CllS J-'•0

(ll

t1 t1

(ll

!ll()Q (ll

zr;Ill

(ll

< ,;Ill,.... 0.0 Ill ;j O.N (ll 0

,_.;j

. r-~:.:. IPARAMO Itower bunchgrosspor/:::: 1

4000

(ll ()(I)

() ~

'< ~

,.... Ill

()(I)

()

(ll

,_.;:r

sO'"llls

1-'•M"

Ill,.... ;j ()

oz 0 ::E: t1

3500

O.Cil 1-'·1:'1

.....

'"""'C"l

(ll t1 t1 0 Ill (I) (I)

{UPPER) ANDEAN FOREST BELT

3000

3 000

{UPPER) ANDEAN Weinmannia FOREST BELT

Fig. 10. Distribution of some selected endemic taxa of the zonal paramo vegetation.

Bucquetia glutinosa; B. vernicosa Diplostephium phylicoides c Rhynchospora paramorum d Plantago sericea ssp. argyrophylla a

â&#x20AC;˘ Rhynchosporo poromorum

PARAMO DE LA RUSIA: Rio Surba valley; 315 0 m Dry upper Weinmannia tomentosa (W. t .l forestline and Espeletiopsis pleiochasia shrubparamo G)

Fig. II . Shrub paramo with Espeletiopsis pleiochasia (I) at 3150 m on the dry eastern side of the Paramo de la Rusia.

SIERRA NEVADA DEL COCUY: Alto de la Cueva

3880 m

S H RUBPARAMO

Fig. 12. Shrub paramo vegetation profile across small moraine valley at 3880 m near the Alto de la Cueva, Sierra Nevada del Cocuy (Boyaca): zonal and azonal vegetation.

Espeletiopsis colombiana-community (degraded shrub paramo) Senecio vaccinioides shrub 62b Oritrophio-Wernerietum pygmaeae cotuletosum 65a Hyperico-Plantaginetum rigidae 73 Senecio andicola-shrub with Espeletia lopezii (rel. 421) I 2

E. c.

Paramo de Pisva: El Cadillal ( 3480 m) Subparamo

Fig . 13. Vegetation profile from the borderline of the upper and lower subparamo at 3480 m near El Cadillal , Paramo de Pisva (Boyaca). Shrubs of Eupato1•ium (Ageratina) tinifoliwr Acaeno cylindristachyae - Plantaginetum sericeae 54 Lupino alopecuroides - Mimuletum glabratae 62b Oritrophio limnophili - Wernerietum pygmaeae cotuletosum 112 Community of Acaena cylindristachya E.c . Espeletiopsis colombiana O.c . Orthrosanthus chimboracensis 3

dw:r~h-;-u;;

@dense Arcytophyllum nitidum of Carex jamesonii

@3) community

Paramo de Sumapaz Alto de Lagunitas; Los Saladeros 3550 m

Fig. 14. Zonal dense Arcytophyllum nitidum dwarfshrub paramo (5) and azonal communities, e.g. community of. Carex jamesonii (52), at 3550 m on theW side of the Paramo de Sumapaz (Cundinamarca)

2 71

Espeletia miradorensis (type locality) with Breutelia sp. and Xyris acutifolia Baccharis revoluta Diplostephietum revoluti

1m MACIZO DE BOGOTA; Usaquen

3160 m

速Arcytophyllum nitidum dwarfshrub paramo with Sporobolus lasiophyllus ( rel. 89)

Fig. IS Dwarfshrub of Arcytophyllum nitidum with Sporobolus lasiophyllus and Achyrocline lehmannii (6). Dry, stony subparamo with Espeletiopsis corymbosa and Gaultheria rigida at 3160 m near Bogota. I 2

4 5 6

7 8 9 10

II 12

Sporobolus lasiophyllus Arcytophyllum nitidum Espeletiopsis corymbosa Niphogeton glaucescens Hypochoeris taraxacoides Gaultheria rigida Achyrocline leJ~annii Calamagrostis effusa Hypericum strictum Bulbostylis tropicalis Paepalanthus paramensis Baccharis tricuneata

MACIZO DE BOGOTA: Paramo de Cruz Verde, 3460m Dwarfshrub pc:iramo of Arcytophyllum nitidum & Diplostephium phylicoides (ret. 57)

Fig. I 6. Dwarfshrub of Arcytophyllum nitidum with Diplostephium phylicoides (7) at 3460 m in the Paramo de Cruz Verde, E of Bogota. I

4 5 6 7

8 9 10

II 12

Aragoa cupressina Rhynchospora paramorum Paepalanthus villosus var. andicola Arcytophyllum nitidum Diplostephium phylicoides Cladonia confusa Campylopus sp. (2808) Vaccinium floribundum var. marginatum Pernettya hirta Calamagrostis effusa Geranium multicaps Hypericum strictum

PARAMO DE SUMAPAZ ; headwaters Laguna El Sorbedero . 3560 m ( re l. 22)

速 Arcytophyl lum nitidum community in bamboo dwarfshrub p6ramo 0

depth profile 25 em 100

em 120

Fig. 17.

Arcytophyllum nitidum community with Xyris acutifolia (8) in bamboa-dwarfshrub paramo at 3560 m N of the Laguna El Sorbedero, Paramo de Sumapaz (Meta) . I

2 3

4 5 6

7 8 9 10 II

Xyris acutifolia Rhynchospera paramorum Carex sp. Paepalanthus lodiculoides Castratella piloselloides Campylopus richardii Hypericum strictum Gentianella corymbosa Calamagrostis effusa Oreobolus obtusangulus ssp. rubrovaginatus SwaUenochloa sp. Arcytophyllum nitidum

pH 4.6 E 0

PARAMO DE

PALACI 0

3530 m

Sphagnum- Breutelia- Swa llenochloa slope bog ( rel.85)

Fig . 18. Azonal community of Swallenochloa with Sphagnum and Breutelia (10) on boggy slopes at 3530 m in the Paramo de Palacio , NE of Bogota. I

4 5 6

7 8

9 10

Swallenochloa tesselata Breutelia allionii Riccardia sp. and Kurzia sp . (3781) with Cephalozia dussii , Blepharostoma trichophyllum, Anastrophyllum nigrescens, Lophocolea coadunata, Jungermannia sphaerocarpa Sphagnum sancto- josephense Gongylanthus innovans Sphagnum magellanicum Geranium multiceps Senecio sp. (j uv-. ) Calamagr ostis effusa Isoetes cf. boyacensis

PARAMO DE GUANTIVA : Laguna . El Alcohol 3785 m Bamboo paramo of Swallenochloa wi th Jensenia erythropus and Espelia d iscoidea var. brevis (re i. 34)

( re l. 34)

Fi g . 19. Bamboo paramo of SWaLLenoahLoa with Eryngium humiLe and Jensenia ery thropus (II). St emrosett e s of EspeLetia disaoidea var. br evis are associated near the Laguna El Alcohol at 3785 m in the southern Paramo de Guantiva. I

2 3

4 5 6 7 8 9 10 II

I2 13

14 15

OreoboLus obtusanguLus ssp. rubrovaginatus SwaLLenoahLoa sp. Sphagnum ayaLophyLLum CaLamagr ostis effusa Vaaainium fLori bundum var. ramosissimum/Pernettya pr ostrata var. purpurea Bartsia sp. EspeLetia di saoidea var . br evis Isoetes kiLLipii Carex piahinahensis Rhynahospora maaroahaete Hypericum sp. Senecio ab-Z:e t inus Sphagnum auspidatum Br euteLia sp . (189 2) Jensenia erythropus

PARAMO DE GUANTIVA: Laguna El Alcohol 3825 m Swallenochloa bamboo pciramo with Castratella piloselloides and Oreobolus obtusangulus ssp. rubrovaginatus (rel.35)

Fig. 20.

SwaZZenochZoa bamboo paramo with CastrateZZa piZoseZZoides and OreoboZus obtusanguZus ssp. rubrovaginatus (12). Stemrosettes of EspeZetia congestiflora are associated at 3825 m in the southern Paramo de Guantiva. I

2 3 4

5 6 7

8 9 10 II

12 13 14 15

EspeZetia congestiflora SwaZZenochZoa sp. Hypericwn strictwn CastrateZZa piZoseZZoides Halenia sp. (1834) ArcytophyZZwn nitidwn CaZamagrostis effusa Jamesonia bogotensis OreoboZus obtusanguZus ssp. rubrovaginatus Gaultheria anastomosans Vacciniwn floribundum var. ramosissimum, Baccharis tricuneata GentianeZZa corymbosa CaZamagrostis bogotensis CampyZopus cZeefii Carex cf. pichinchensis (juv.)

WNW

ESE

PARAMO DE SUMAPAZ ; Clio . La Robono, 4010 m ~a Swollenochloo- Colomogrost i s effuse paromo with Espeletio grondifloro . \:J Oreobolus obtusongulus ssp. rubrovoginotus . Disterigmo empetrifol ium and Poepolonthus korstenii vor. co rei (rei. 26)

Fig. 21.

Community of Swal l cnochloa with Oreobolus obtusangulus ssp. rubrovaginatus, Rhacocarpus purpurascens, Oritrophium peruvianum and Paepalanthus karstenii var. corei (13a) at about 4000 m on the Cuchilla La Rabona, Paramo de Sumapaz (Cundinamarca). I

2 3

4 5 6

7 8 9 10 II

Espeletia grandiflora Calamagrostis effusa Oreobolus obtusangulus ssp. rubrovaginatus Paepalanthus karstenii var. corei Disterigma empetrifolium Swallenochloa ct. tesselata Carex pichinchensis Carex cf. tristicha Campylopus pittieri Arcytophyllum muticum Gymnomi triaceae Grammitis (Ctenopteris) moniliformis

(ret.362) PARAMO DE LA SARNA, N. of the Toto - lake, 3550m Lower Calamagrostis effusa bunchgrass p6ramo with Espeletiopsis guacharaco

Fig. 22. Lower Calamagrostis effu sa bunchgrass paramo with Espele t i opsis guacharaco at 3550 min the Paramo de la Sarna, N of the Lake Tota (Boyaca). I

2 3

4 5 6

Espeletiopsis guachar aco Arcytophyllum nitidum Calamagrostis effusa Gongylanthus liebmannianus , Cladia aggr egata Campy l opus pitti er i Leptodontium pungens

Fig. 23 . Lower Calamagrostis effusa bunch grass paramo wi th Espeletia grandiflora , Oreobolus obtusangulus ssp. rubrovaginatus and Castratella piloselloides (15) at 34 75 rn in the Paramo de Cruz Verde, E of Bogota. I

2 3

4 5

6 7 8

9 10 II

Espeletia grandiflora Calamagrostis effusa Castratella piloselloides Rhynchospora paramorum Oreobolus obtusangulus ssp . rubrovaginatus Rhynchospora macrochaete Arcytophyllum nitidum Gentionella corymbosa Hypochoer is sessiliflora Carex sp. Paepalanthus andicola var. villosus AzoreUa a ff. euatre- casasii

NNW

PARAMO DE CRUZ VERDE : La Viga. 3475m Q. Lower Calamagrostis effusa- Espeletia grandiflora bunchgrass paramo ~ with Oreobolu s obtusangulus ssp . rubrovaginatus and Castratella piloselloides (ret. 58)

SSE

NNW

SSE

PARAMO DE GUANTIVA ; W of Belen, Alto de Las Cruces, 38 10m (;.;;\ Lower Calamagrostis effuse bunchgrass pciramo V 路 with Espelet ia brachya x iantha and Oreobolus obtusangulus ssp. rubrovaginatus (rel.30)

Fig. 24. Lower Calamagrostis effusa bunchgr ass paramo witn Or eobolus obtusangulus ssp . rubr ovaginatus (I6). Stemro s ettes of Espeletia brachyxi antha are associated in a stand at 38IO m near th e Alto de las Cruces (Vereda S. Jose de la montana),

W of Belen (Boyaca). I 2

4 5 6

7 8 9

IO II I2

Espe l etia brachyaxiantha Calamagrostis effusa Orthrosanthus chimboracensis Senecio vaccinioides Senecio abietinus Carex cf. conferto- spicata/C. tris t icha Acaena cylindristachya Ar cytophyllum muticum 路 Paepalanthus kar stenii Or eobolus obtusangulus ssp . rubrovaginatus Po lyt r ichum j uniperinum Jamesonia rotundifolia

PARAMO OE GUANTIVA. W of Belen. 3865 m @ lower Colomogrostis effuse bunchgrass paramo with Espelelia

Fig. 25. Lower Calamagrostis effusa bunchgrass paramo with Espeletia boyacensis (17) and Acaena cylindristachya at 3865 m in the southern Paramo de Guantiva near the Alto de La Cruces, W of Belen (Boyaca). I

2 3

4 5 6 7 8 9 10

Espeletia boyacensis Vaccinium floribundum var. ramosissimum Leptodontium pungens Geranium sibbaldioides Acaena cylindristachya Paspalum bonplandianum Paepalanthus_ karstenii var. cor ei Catamagrostis effusa Arcytophyllum muticum Azorella aff. cuatrecasasii

PARAMO DE PISVA : El Cadillal, 3440 m Subparamo

Fig. 26. Vegetation profile in the borderline of the upper and lower s ubparamo at 3440 m near El Cadillal, Paramo de Pisva (Boyaca). Shrub of Eupatorium (Ageratina) tinifolium Acaena cylindristachya - Plantaginetum sericeae (rel. 102) 74 Hypericetum lmâ&#x20AC;˘ici folii (probably) 112 Community of Acaena cylindris t achya (rel. 103) E.c Espeletiopsis colombiana O.c Orthrosanthus chimboracensis 3

Laguna Cuadrado

t moraine

ltm Sierra Nevada del Cocuy: Alto Valle Lagunillas, Laguna Cuadrado. 4060 m

Fig. 27. Schematic vegetation profile across moraine supporting zonal upper bunchgrass vegetation with Espeletiopsis colombiana (19) and locally Acaeno-Plantaginetum sericeae (18). Other azonal communities are the Aciachnetum pulvinatae (107) and dense Espeletia lopezii stands (120) which border the peatland with e.g. Muhlenbergietum fastigiatae (108) along the southern shore of the Laguna Cuadrada at ca 4060 min the Sierra Nevada del Cocuy (Boyaca).

alt . m

4300

4200

"' u"' 4100

1 c

4000

Sierra Nevada del Cocuy: Q.El Play6n, S. Jose drainage near Patio Bolos

3900

Fig. 28 Schematic vegetation profile across the eastern slope of the Sierra Nevada del Cocuy near Patio Bolos showing the position of various zonal high paramo communities: 13a

Swallenoch~oa

bamboo paramo with Oreobolus obtusangulus ssp. rubrovagina-

tus 20 21b 23 24 26 63 E.c E.l

Upper Calamagrostis effusa bunchgrass paramo with Espeletia cleefii

Loricarietum complanatae racomitrietosum Community of Pernettya prostrata and Luzula racemosa Community of Espeletia cleefii with Geranium sibbaldioides Community of Senecio niveo-aurens Floscaldasio-Distichietum muscoides (azonal) Espeletiopsis colombiana Espeletia lopezii

Fi g . 29. Zonal and a zona l ve getation of the lowe rmo s t s upe rparamo a t 4075 on th e W slope of the Nevada de Sumapa z (Meta). ?- I b

28a 85

92 118

Lor icarâ&#x20AC;˘ietum camp lanatae racomi trietosum Community of Lachemilla nivalis with Jamesonia goudotii Senecionetum vernicosi Dwarfshrub of Diplostephium rupestre Azor elletum mu ltifidae

SIERRA NEVADA DEL COCUY: Paramo Concovo. 4320 m Borderline superp6romo - bunchgrossp6romo

Fig. 30. Shrub of Senecio vaccinioides and DipZostephium rhomboidaZe (22) in the boundary of the zonal upper grass pararno (19) and superpararno (2Ja, 23) at 4320 rn in the Paramo C6ncavo, Sierra Nevada del Cocuy (Boyad.).

SIERRA

NEVADA

DEL

COCUY; Q.Bocatoma, 4270 m

Community of Pernettya

prostrate and

Luzula

racemose

l路

Fig. 31. Lower superpararno community of Pernettya prostrata and LuzuZa racemosa (23) I

2 3 4 5

LuzuZa racemosa Pernettya prostrata var. prostrata Senecio cocuyanus Poa sp. Agrostis brevicuZmis

速

SIERRA NEVADA DEL COCUY: Patio Bolos, 4350 m Lower superparamo: zonal communities

Fig. 32. Zonal lower superparamo communltles on gravelly slopes and outcrops at Patio Bolos (4350 m): Agrostis breviculmis community with Acaulimalva purdiei (25), Senecio niveo-aurens communi.ty (26) and the Valeriana plantaginea community with Racomitrium crispulum (27). In the wet depression Floscaldasio-DistichietUm cushionbog (63) .

Isoetetum karstenii a b Reconstruction of the habitat of subass. typicum @ and ditrichetosum@ in moraine-dammed superp6ramolake at c. 4350 m in the Sierra Nevada del Cocuy

Fig . 33.

Isoetetum karstenii (29). Reconstruction of the habitat of the subass. typieum (29a) and the ditrichetosum (29b) in a moraine dammed superparamo lake at c. 4350 m in the Sierra Nevada del Cocuy.

SIERRA NEVADA DEL COCUY; Laguna Cuadrado, 4060 m Schematic ' zonation of the Isoetetum glacio lis prov . @ Normal waterline NWL Approximate extremely low waterline of March 1973 LWL

Fig . 34.

Isoe tum glacialis prov. (30) in the Laguna Cuadrada at 4060 m in the Sierra Nevada del Cocuy (Boyaca), schematic zonation.

Sierra Nevada del Cocuy; Cusirl, 4310m HWL High water line ( rel.338 type)

Fig. 35.

Isoet etum soci ae (31) in a lower superparamo pond at 4310 m on the Alto de Cusiri, Sierra Nevada del Cocuy (Boyaca)

I SOETETUM ( STYLITETUM) ANDICOLAE V) (1)

"1:::1

路c:;

0:::.

"1:::1 :::;,

(1)

l::l..

0:::.

(1)

.!;?

-e <.::>

;::;:

路e. 0:::. l.J

:::;,

路e.

ISOETETUM ANDICOLAE

rel. 292A

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ high water level (estimated I

S~u~m~a~p~a~z~.~~~~?''K~~~~~~bt~~~~~~~~~::::::~~::::j

Paramo deS

Laguna del Medio; South shore. 3620 m vertical scale

Fig. 36.

Isoetetum andicolae (32) at 3620 m along the southern shore of the Laguna del Medio, headwaters Q. Sitiales in the Paramo de Sumapaz (Meta).

PARAMO DE SUM A PAZ: Laguna Gobernador, 3815 m (,;:;\. Isoetetum cleefii (rel.301 type) low water level 26 jan. 1973

Fig. 37.

Isoetetum cleefii (33) along the northern shore of the Laguna Gobernador at c. 3815 m on the W side of the Paramo de Sumapaz. I

2 3

4 5 6

7 8

Chlorophyta Swallenochloa cf. tesselata Pleurozium schreberi Sphagnum cf. cuspidatum Espeletia sp. (E. grandiflora complex) Calamagrostis effusa Diplostephium revolutum Calypogeia andicola

direction of predominant strong wind

DE LAGUNA VERDE NW of Neusa 3700 m aa 路 lsoetetum palmeri b var. of Drep exann. Xyris acutofolia bog

@ @ Fig. 38.

Isoetetum palmeri: variant of Drepanocladus exannulatus (34aa}. Lower bunchgrass paramo lake at 3700 m near the Laguna Verde, NW of Neusa.

Xyris acutifolia bog (70b) is present on the western shore. I

2 3

4 5 6

7 8

Isoetes palmeri Callitriche sp. (6253) Batrachospermum sp. Myriophyllum elatinoides Eleocharis acicularis Depranocladus exannulatus Puya santosii Xyris acutifolia

hwl awl r-~~~--------~~9~----------------~~~~~~~

PARAMO DE LAGUNA VERDE. NW of Neusa, 3700 m 0 Tillaeetum paludosae isoetetosum

@ Fig . 39.

Zonation of the Tillaeetum paludosae isoetetosum (36a) and the Isoetetum palmeri, variant of Drepanocladus exannulatus (34aa) in a small lake at 3700 m in the lower bunchgrass paramo near the Laguna Verde, NW of Neusa. 2

Sphagnum sp., Elatine chilensis floodmark of detritus of Isoetes and Sphagnum

Tillaea paludosa

For other conventions see Fig. 38 (same lake) .

hwl: high water level awl: waterlevel on nov. I I , 1972

·· ·· .· .. .. .

PARAMO

DE GUAN Tl VA; headwaters

@.Vb Tillaeetum

paludosae

Q .Min as, 3850 m

subass . typicum (rel.41,type)

Fig. 40.

Tillaeetum paludosae (36). Amphibious vegetation of the subass. typicum

(36a) in pond in bamboo-bunchgrass-para mo at 3850 m in the southern Paramo de Guantiva .

Tillaea paludosa Isoet es socia 3 Ranunculus limoselloides I

Phragmitetea? --i~Potametea-u- lsoetetea-u--- Charetea ------11--lsoetetea-i~Polomelf-limoselleleo ---l -teo 49

Paramo de Sumapaz

Schematic toke hydroserol sequence (3400- 3600 ml

Fig. 41. Schematic zonation of vegetation in a lake in the lower paramos of the Paramo de Sumapaz . The Nitellion clavatae-flexilis (Rangel & Aguirre, in press) is supposed to be present on the lake bottom in deep water.

'il

"'.,..,

0.,..,

"' <"'")

"' ,.,

.,..,

<"'")

~:> "'

"' ;:J

...QJ

i"' c:

;:J

"' QJ

...QJ

,..,"" "'

l .D

速

IW1?1UOpU1?111 l?ll1111<Hp1?1

速

SU01lJSn:> ep181.1

.,..,

Fig . 42. Vegetation zonation along the peaty shore of the Laguna Seca at about 3650 m in the headwaters of Rio Chuza, NE of Bogota. Hydroseral sequence: 40 Hydrocotyio ranuncuioides - Myriophyiietum eiatinoides 65b, 62a Oritrophio - Wernerietaiia 55b Geranio-confertae-Caiamagrostietum Iiguiatae breuteiietosum 55ba id. var. of Campy?.opus cavifo lius 10 Community of Swailenochioa with Sphagnum and Breutelia

~~~~~~~~~ti~~~t~~.l~!~;~~~;,'\\~j~

Paramo de Sumo paz; Laguna La Guitarra , 31.25 m a

Eleocharitetum ma cro st ach yae myriophylletosum (rei. 300A, 300 B)

tillaeetosum (rei. 300)

' - - - -- - - -- - - - - - - - - - - - -- -- -

·--· - - --

I -

-·- - · j

Fig. 43.

ELeoeharite tum maer ostaehyae (41) in the Laguna La Guitarra (3425 m), Paramo de Sumapaz, showing the location of the myriophyLLetosum (4Ja} and the tiLLaeetosum (41b) . Cortaderia nitida PLantago rigida BLeehnum Loxense 4 Potamogeton asplundii I

2 3

em 40 30 20 10

peaty clay

gy t t j a ( 7 • 5 YR 2 I 1) containing Isoetes macrospores

Paramo de Guantiva (Belen) rel. veg . 404 (3700 m)

Fig. 44.

ELeoeharitetum maerostaehyae tiUaeetosum (41b) at 370.0 m in a small lake in the southern Paramo de Guantiva. near the Alto de Las Cruces, W of Belen (Boyadi) .

Eleoeharis maerostaehya 2 ELatine ehilensis 3 Drepanoeladus revolvens

4 Ranuneulus U moseUoides 5 CaUitriehe sp .

Si e r ra Ne v a da de l Cocuy Pa r amo C6n c avo , 43 15 m

Re l. veg. 45 4

~.-.--..--~

Fig. 45.

Phi lonoto- Isotachidetum serrulatae (43) in high paramo str eams in the Si e r ra Nevad a de l Cocuy (Boyaca). a b

cross ec tion map

peat bog

PARAMO DE LAGUNA VERDE . NW of Neusa. 3600 m

Community of Eleocharis acicularis

Fig. 46 . Community of Eleocharis acicularis (45) in Sphagnum bog at 3600 m in the l ower bunchgra ss pa r amo s n ear th e Laguna Verde, NW of Neu s a .

Sphagnum cuspidatum Eleochar is acicularis

PARAMO

SUMAPAZ:

Laguna La Guitarra, 3425 m Senecionetum reiss iani ( rel5 )

@ UJ

(!)

;:::l

UJ ~

•.-l

(1j

(!)

UJ ~

,..c::

•.-l

(!)

UJ UJ

(!)

..c(j

•.-l

(!)

0 .....,

!--!

·.-l

..c(j

•.-l

•.-l (j

(!)

.\J

(!)

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(1j

,........

1..0

(1j

...::t

·~

;:::l

4-l

:> (!)

(!)

,..c::

•.-l .\J

(!)

(1j

~ (1j UJ

(1j

(!) (!)

(1j

.\J ~ (1j

p..

(1j

•.-l !--!

•.-l ~

s;:::l

(!)

•.-l bO

•.-l !--! .\J

Cll

(1j

(!) ~

(1j

::>

bO (1j

,..c::

CJ:l

6.5

L_____.J

Im Fi g. 47.

Senecionetum reissiani (48) at 3425 m ne ar the ma rshy south e rn shore of th e Laguna La Guitarra, Paramo de Sumapaz (Meta).

0.5 CAR I C E T U M

P I C H I N CHEN S I S

(type)

Fig. 48.

Caricetum pichinchensis (49). Schematic detail of hummo ck-hollow topography in stand at 3660 min the headwa ters of Ri o S. Rosita , Chisaca (Cundinamarca) . hummock: Chori3odontium s p. (5194) Pernettya prostrata var. elliptica Breutelia inclinata Thui dium peruvianum 2

hollow:

Lachemilla mandoniana Cotula minuta Breutelia inclinata Symphyogyna sinuata

rel. veg. -

292

=-!

rel. veg.

~------

293

Laguna La 路Guitarra, Sumapaz (c. 3400 m)

pH 6.6

pH 5.4

pH 6.6

peaty clay

Fig. 49. Vegetation zonation along the marshy SW shore of the Laguna La Guitarra at c. 3400 m (Paramo de Sumapaz, Heta) with a sequence of Poto:meto-MyriophyUion (40), Calo:magrostis ligulata community with Mantia fontana (56), and Caricetum pichinchensis (49). hummock:

Carex pichinchensis Valeriana plantaginea var. paludosa (var. ined) Stokesiella praelonga Breutelia sp. (8258)

Ranunculus flagelliformis Marchantia plicata 3 Ranunculus flagelliformis, Eleocharis stenocarpa, Mantia fontana 4 Eleocharis stenocarpa 5 Myriophyllum elatinoides 2

hollow:

-direction prevailing wind

LAGUNA

LA PRIMAVERA, Paramo de Sumapaz

3530 m

Fig. 50. Vegetation zonation in the Laguna La Primavera at 3530 m in the Paramo de Sumapaz (Meta). See also fig. 51 .

Lower Calamagrostis effusa paramo with Espeletia grandiflora and Oreobolus obtusangulus ssp. rubrovaginatus Potameto-Myrriophyllion elatinoides Caricetum pichinchensis Community of Carex acutata (rel. 267A) Community of Calamagrostis ligulata with Sphagnum sancto-josephense

Dip lostephietum revo luti

39 49 51

(rel. 267)

LAGUNA

PRIMAVERA

( 3525 m )

Cortaderia nitidia

'!:100m

moraine

outlet

Fig. 51. Sketch of the vegetation zonation in the western part of the Laguna La Primavera at 3525 min the Paramo de Sumapaz (Meta).

PARAMO DE LA RUSIA ; Aislada, 3500m Cyperetum rivularis (re1.234&235)

Fig . 52 .

Cyperetum rivularis (53) I Cyperus r ivularis ssp. lagunetto 2 Lycopodium conti gnum 3 Castr atel l a piloselloi des 4 Aragoa cupr essina 5 Swallenochloa s p. 6 Espeletia murilloi Xyris subulata

ENE

WSW

PARAMO DE SUMAPAZ : Alto Caicedo, 3845m ligulatae drabetosum rel.127, type subass.)

~aGeranio- Calamagrostietum

v ( Fi g. 53.

Hummock-hollow r e lief in the Geranio confer tae - Calamagrostietum ligu l atae drabetos um (55a) I Breutelia chrysec Cerastium imbricatum Muhlenbergia cf. fastigiata Bryum sp . (4818) Br achyt hecium sp . (4819) 2 Cyclodictyon sp. (4820) Cardamine s p . 3 Senecio niveo- aureus 4 Lupinus cf . verjonensis 5 Dr aba sp . ( 2611A/whit e petals)

young moraine

rel.314

peat

-------------

{ 4315 m)

SIERRA NEVADA DEL COCUY : Paramo Concave lower superpciramo: zonal and azonal vegetation

young m oraine

Ism young

SIERRA NEVADA DEL COCUY: Paramo Concave { 4315 m) : lower superp6ramo

moraine

rel.313

Fig. 54 & 55 . Vegetation profile and map of zonal and azonal lower superparamo vegetation at 4300 min the Paramo C6ncavo , Sierra Nevada del Cocuy (Boyaca) . Community of Pernettya prostrata and Luzula raaemosa Philonoto-Isotaahidetum ser rulatae (rel. 454) Cariai penaophilae-Wernerietum arassae aariaetosum penaophilae 6Ib 62aa Variant typiaum of Oritrophio-Wernerietum pygmaeae 120 Dense Espe letia lopezii grove on peat S. and . Senecio andiaola c. lig . Calamagrostis ligu lata 23 43

PARAMO DE GUANTIVA, headwaters Q. Minas, 3780 m Qacori t rophio limnophi li - Werneri etu m pyg maeae subass. typicum var. of Sphagnum cyctophyllu m ( rel.39, type)

Fig . 56 .

Oritrophio limnophili- Wernerietum pygmaeae (62) . Detail of flush - vegetation of the v ari ant of Sphagnum cyclophyllum (62ac) on wet glacial grass paramo valley flo or at 3780 m in the h e adwaters of Q. Minas , southern Paramo de Guant i v a . I 2 3

4 5 6

Oritrophium limnophilum ssp . mutisianum Plantago rigida Werner ia pygmaea Sphagnum cyclophyllum Gentianella nevadensis Vesicar ex collumanthus Hypochoeris sessi liflora

PARAMO DE SUMAPAZ; Andabobos, 3750 m Oritrophio Limnophili - Wernerietum pygmaeae @ad var. of Drepanocladus revolvens (rel.506)

Fig . 57 .

Oritrophio limnophili- Wernerietum pygmaeae (62) Hollow veget a tion of the variant of Dr epanocladus_ revolvens (62 ad) in cushionbog of the Hyperico - Plantaginetum rigidae br eutelietosum (65b) Werneria pygmaea Or itr ophium limnophilum ssp . mutisianum Calamagrostis coar ctata 4 Drepanocladus r evolvens 5 Plantago rigida 6 Chor isodontium speci osum I

2 3

SIERRA NEVADA DEL COCUY: Superparamo, Patio Bolos 4300 m

Fig. 58.

Floscaldasio-Distiahietum muscoides (63) at 4300 m in the lower superparamo near Patio Bolos, Sierra Nevada del Cocuy (Arauca). Adjacent are zonal communities of Agrostis breviculmis with AcauUmalva purdlei (25); of Senecio niveo-aurens (26) and of Valeriana plantaginea with Racomitrium crispulum (27).

"' .........."'

Oj)

3: "' "' "'

.........."' ~

c: .~

;:l 0'

1-1 0

p..

"'o~::l"'

1-1

.... (.)

....; (.)

<dP..

(.)

"'"' "'"' 1-1

(.)

;:l

p..

~ ~

;:l

1-1 1-1

~ ~

;:l

1-1 1-1

1-1

1-1 Q)

"' ....'1:10 Q)

(.)

nl<ll

.... ;:l

Distichia peat

"""-'..C:S (.) Q) 0

:>. C1l

....

(.) Q)

....

'1:1

Valle Bocatoma Sierra Nevada del Cocuy rel. veg. 333 (4100 m)

Fig. 59. Community of Distichia muscoides with Isotachis serrulata and Campylopus fulvus (64) at 4100 m on a former glacial lake in the Bocatoma valley, Sierra Nevada del Cocuy (Boyaca).

water pH : 5.1-

5.2

~ 路路

Bocatorna Valley (4100 rn) Sierra Nevada del Cocuy

~Distichia rnuscoides cushion building in aquatic habitat

Fig. 60. Possible development and decay of Distichia muscoides cushions in aquatic habitat as observed in the stand of Fig. 59. vital Distichia muscoides with Isotachis serruZata and algae (c拢. Micro-

spora) 2 3

vital Distichia muscoides cushions decaying Distichia muscoides cushion with OreoboZus obtusanguZus, and Riccardia sp. colonizing first (a); later follow grasses (Cortaderia sp., CaZamagrostis effusa), algae (8758) and mosses (CampyZopus cavifolius, C. fuZvus) decaying Distichia muscoides cushion with podetia of CZadonia subg. Cenomyce (8761) on top of the dry cushions. Lycopodium sp., FZoscaZdasia hypsophiZa, Pernettya prostrata var ~ purpurea, Hypericum Zancioides, Bartsia sp. , Senecio flos-fragrans var. frigidophiZus, LachemiZZa nivaZis, Loricaria compZanata, and DipZostephiUm rhomboi~ daZe may arrive. PseudocephaZozia quadriZoba, CephaZozia dussii and CaZZiergon trifarium grow over the OreoboZus cushions. the ringlike pattern of the Distichia cushions is caused by final decay of the oldest central part of the cushions.

......,

....

II)

"' "'""' ~~ 0 1-<

OJ)

II)

:::I

II)

3c::

<ll

1-< .0

.:'!

<ll

路~ 0

OJ)

13 -:;; c:: B ~ p..

:I!

rigida - cushion bog

organic clay (5 YR 3/1)

clay with yellow dots (7. 5 YR 2/2)

PARAMO DE GUANTIVA; Belen, 3800m 0 Hyperico- Plantaginetum rigidae gentianelletosum nevadensis-corymbosae

pH 5.8~80

(rel.410.type)

compact sand (2.5 Y 6/4)

~ttt~

with plant

detritus

Sandstone

Fig. 61 .

Hyperico lancioides-Plantaginetum rigidae gentianelletosum nevadensis (65a) at 3800 min the Paramo de Guantiva, W of Belen (Boyaca).

PARAMO DE SUMAPAZ, Chisac6, 3700 m @b Hyperico -Plantaginetum rigidae breutelietosum (rei. 55)

.......

~ ><

<ll

1-<

em: pH 4.4 1m

clayey Plantago rigida peat

Fig. 62.

Hyperico lancioides-Plantaginetum rigidae breutelietosum (65b). Grazed (Browsed) cushion bog at 3700 m near the Chisaca lakes (Cundinamarca).

Swallenochloa tesselata

Valeriana stenophylla

......

___ ..,

Plantago rigida cushions /

peat drainage

Sphagnum cyclophyllum

HEADWATERS RIO CHUZA, Cundinamaca, 3740 m 1m

@b Hype rico- Plantaginetum rigidae breutelietosum

Fig. 63. Detail of slope bog of the Hyperieo-Plantaginetum rigidae breutelietosum (65b) at 3740 m in the headwaters of Rio Chuza, NE of Bogota.

速a a

ORITROPHIO-OREOBOLETUM OBTUSANGULI

Equisetum bogotense community

(rel.152)

( rel.147)

---- -----

- - - - - - - - ~0

gyttja

pH 5.2

detail:

~aa

ORITROPHIO

OREOBOLETUM

rel.147

rel.152

--- --- ---

OBT.

peat

--------0

HEADWATER$ QUEBRADA CHUZA ( Cundinamarca) - 3730 m

Fig. 64.

Oritrophio peruviani-Oreoboletum obtusanguli (66aa) in grass paramo at 3730 m near the headwaters of Q. Chuza, ENE of Bogota. I Equisetum bogotense 2 Sphagnum auspidatum 3 Oritrophium peruvianum ssp. peruvianum fma. intermedia 4 Sphagnum sanato-josephense & Rhaaoaarpus purpurasaens 5 Werneria humilis var. angustifolia 6 Oreobolus obtusangulus and Plantago rigida 7 Campylopus aavifolius 8 Espeletia grandiflora 9 Calamagrostis effusa 10 Senecio vaaainioides II Puya trianae 12 SWallenoahloa tesselata 13 Rhaaoaarpus purpurasaens & Campylopus sp. 14 Sphagnum aompaatum

PARAMO DE PALACIO . 3100 m

@ Espeletia killipii - Blechnum

1m loxense bog

Fig. 65 .

Sphagnum bog with Espeletia kiUipii and Blechnum loxens路e I Espeletia killipii var. killipii 2 Blechnum loxense 3 Baccharis revolutum 4 Carex pichinchensis 5 Puya goudotiana

<::> 0

en <l>

::E :::::>

<l> .!:.

<::>

-~Iii

a..

Ol 0

-§_

(/)

__.J

0 Ol

::J

m 0

·u

;£~

w __.J

__.J

~ Vl

(Y)

~ '~ a_ - o

§ 0

lll

0 <1:)

0 <D

-..t

Fig. 66.

Sphagnum bog with Swallenochloa (68) at 3600 m near Buitrago, Paramo de Palacio.

Campylopus sp. Eriocaulon microcephalum Sphagnum magellanicum 4 Anastrophyllum nigrescens 5 Campylopus pittieri 6 Breutelia chrysea I

2 3

SIERRA NEVADA DEL COCUY,

Q . Los Osos, 3500

Swallenochloa- Sphagnum bog

Fig. 67.

SwaZZenochZoa-Sphagnum bog (68): Detail of hummock-hollow relief . Upper valley of Q. Los Osos, Vado de Garbancillos at 3500 m in the bamboo paramo of the Sierra Nevada del Cocuy (Arauca).

Lepidozia sp. Sphagnum mageZZanicum Sphagnum sancto-josephense 4 SwaZZenochZoa sp. 5 Leptodontium waUisii, Sphaer ophorus meZanocarpus 6 Pernettya prostrata I

2 3

;; ~ a c a 0 "0

::> 0 0>

(") (")

::> ()._

::> L)

0 0

"' "'0 0 J, E

a .c 'a ()._ 路~ <(

0 t? 0

E ::> c

w a0> 0

.c a.

(/]

~@ ::E ID

Fig. 68.

Sphagnum bog with SwaUenochloa and Puya goudotiana (69a) I

2 3

4 5 6

7 8 9 10 II 12

Puya goudntiana Puya goudotiana (~ Swallenochloa sp. Aragoa abietina Blechnum loxense Diplostephium phylicoides Geranium sibbaldioides Calamagrostis effusa Sphagnum magellanicum Elaphoglossum engelii Paepalanthus andicola var. villosus Polytrichum juniperinum

Eg.

rel.9Z

peat

PARAMO DE PALACIO: subparamo Headwaters Q. Blanca, 3375 m

Fig. 69.

Xyris acutifolia-bog (70b) at 3375 m in the Paramo de Palacio, NE of Bogota. Adjacent communities are Swallenochloa paramo with Oreobolus obtusangulus ssp. rubrovaginatus (13a) and SwaUenochloa- Sphagnwn bog (68, 69a) ..

Espeletia grandiflora Blechnwn loxense Isoetes boyacensis 4 Aragoa abietina 5 Paepalanthus andicola var. villosus 6 Cortaderia nitida I

2 3

PARAMO DE PISVA: Alto de Granados; 3620 m Lower grassparamo

Fig. 70.

Diplostephietwn revoluti (71) with Espeletia lopezii var. major at 3620 m in the Paramo de Pisva (Boyaca). Adjacent are Swallenochloa paramo with Oreobolus obtusangulus ssp. rubrovaginatus (13a), the Oritrophio-Wernerietwn pygmaeae cotuletoswn (62b) and Hyperico-Plantqginetwn rigidae breutelietosum (65b).

peat PARAMO DE LAGUNA VERDE. NW of Neusa, 3680 m lower bunchgrass paramo: zonal & azonal vegetation (schematic)

··-··-:..·:··· ···-···------·· ···········-·· ···-. gyttjo

Fig. 71. Transition from azonal Aragoetum abietinae puyetosum (72bl and the Blechnum loxense-Espeletia chocontana community (16b) towards zonal Calamagrostis effusa lower bunchgrass paramo with Espeletia barclayana, Oreobolus obtusangulus ssp. rubrovaginatus and Castratella piloselloides

Aragoa abietina Puya santosii Xyris acutifolia Sphagnum-pleurocarpous moss layer Espeletia chocontana Blechnum loxense Valeriana stenophylla Juncus ecuadoriensis, Ranunculus limoseUoides Rhacocarpas purpurascens predominant Pernettya prostrata predominant

2 3

4 5 6 7 8 9 10

SENECIONETUM ANDICOLAE ( prov.)

Senecio andicola 255 - - - - - - t

f - - - - rel.

HYPE RICO PLANTAGINETUM RIGIDAE

drainage line

(rel. 254)

pH 6.4 peat

PARAMO

---- --

£ DE LA RUSlA; Pen a Blanca. 3730 m

-- --

-------

Fig. 72.

Senecionetum andicolae (73} and Hyperico-Plantaginetum rigidae (65al at 3730 m near Pena Blanca in the Paramo de la Rusia (Boyaca)..

PARAMO DE GUANTIVA: Belen, Alto de las Cruces, 3765 m.

Hypericetum

brownish sand

laricifolii

Fig. 73.

Hypericetum laricifolii (74) in humid protected valley in grass pararno at 3765 m near Alto de las Cruces, Vereda S. Jose de la montana, W of Belen (Boyaca) . 2 3

Hypericum laricifolium ssp. laricoides Orthrosanthus chimboracensis Acaena elongata

4 5

ericaceous dwarfshrub low mat of Sibthorpia repens, kzoreUa multifida and Thuidium peruvianum

PARAMO DE GUANTIVA headwaters Q.Minas, 3980 m

@ Cortaderio- Arcytophylletum

cora coso n i

Fig. 74.

Cortaderio sericanthae-Arcytophylletum caracasani (86) on rocky slopes above Polylepis quadrijuga dwarfforest in the headwaters of Q. Minas, Paramo de Guantiva.

Arcytophyllum caracasanum Cortaderia sericantha Calamagrostis effusa 4 musci: Rhacocarpus, Racomitrium, Campylopus richardii 5 Oreobolus obtusangulus ssp. rubrovaginatus I

2 3

Fig. 75. Patches of PoLyLepis quadrijuga-dwaYfforest (98) in zonal grass paramo (11, 15, 17). Azonal meadows (108, 110) and flush vegetation (62ac) is present on the humid and wet valley floor. 1 2 3

4 5 6

Espeletia grandiflora ssp. boyacensis Espeletia congestiflora Espeletia boyacensis Espeletia discoidea var. brevis SwaLLenochLoa sp. Hypericum trianae Werneria pygmaea

black clay

pH 4. 7

100 em

LORENZOCHLOETUM ERECTIFOLIAE

LAGUNA SECA, 3640 m Paramo between Cogua and S. Cayetano {rei 187)

速 Fig. 76.

LorenzochZoetum erectifoZiae (76) in the lower bunchgrass paramo at 3640 m near the Laguna Seca between Cogua and S. Cayetano (Cundinamarca).

LorenzochZoa erectifoZia Sibthorpica repens Marchantia berteroana 4 CampyZopus sp. (6101) 5 CZadonia cf. fimbriata (6103) 6 CampyZopus cf. pittieri I

2 3

@ predominant

wind

Q.Bocatoma

SIERRA

NEVADA

Agrostietum

DEL

COCUY, headwaters

foliatae

{prov) superparamo

Q .Bocatoma, 4280m

(rel.179)

Fig. 77.

Agrostietum foZiatae (109) on the sandy, frequently flooded shores of the braided Bocatoma stream at 4280 m in the superparamo of the Sierra Nevada del Cocuy (Boyaca) .

Senecio cocuyanus on moraine with zonal Pernettya prostrata-LuzuZa racemosa vegetation 2 Agrostis foZiata 4 AnastrophyZZum sp. 5 Aphanocapsa gerviZZei

-------- -------------------------------------------------------~

PARAMO DE LAGUNA VERDE , NW of Neuse , 3670 m Lower bunchgrass poramo : zonal and azonal vegetation.

Fig. 78. Zonal lower Calamagrostis bunchgrass paramo commun1t1es (I4, I5) in contact with azonal dense Espeletia barclayana stemrosette community (I20) and the Aragoetum abietinae puyetosum (72b) at 3670 m in the vicinity of the Laguna Verde, NW of Neusa (Cundinamarca). 2

4 5

Espeletia barclayana Espeletia chocontana Espeletiopsis corymbosa Xyris acutifolia Puya sp . Aragoa abietina

BUNCHGRASS PARAMO

BAMBOO BUNCHGRASS PARAMO

BAMBOO PARAMO

LOWER GRASS PARAMO ( Schematic cross -secti ons )

Fig . 79. Schematic cross-sections through zonal vegetation in the lower grass paramo demonstrating a. bunchgrass paramo, b. bamboo-bunchgrass paramo and c. bamboo paramo. The Sphagnum bog (68/69) in bamboo paramo valleys are azonal and grade into azonal Swallenochloa communities with Sphagnum (IO) and other bamboo communities (II, I2, I3). The cover of the ~amboos versus bunchgrass depends on the degree of moisture. Only Gramineae are depicted.

Water deficit

Statio n

Number of vera humid months with precipitation exceed ing 100 resp 5 mm and mean annual precipitation ( mm l 1

3000mm

(*Andean forest belt )

Chuza, Golillas 13350 m)

BAMBOO

PARAM O

2500

*Chuza, Monterredondo (3100m)

Las Do ntas, Sumapaz 13400m) * Chingaza 13250 m) 2000

Palacios -Calera I 3500 m I

Palacios-Guasca l3760m) La Primavera , Sumo paz (3460 m) 1500

BAMBOO-BUNCHGRASS PARAMO Alto Caicedo I 3800 m) El Verjon 13249ml Chisacci l3700m) 0

~~~~~ocN?d~e1~\~}U~ ?m 1 8

Neusa, represa I 2980 mI

1000

*Chita I 3005 ml

PARAMO

BUNCH GRASS

~f'~~1路o5?~1tgo~r ( 3230 m)

-r 0

m~nth

nu~ber oi 0mont~~

Fig. 80. Relation between mean annual prec1p1tation (in mm), number of humid months (>50 nnn - h atched bars) and very humid months ( > 100 nnn - black bars) and zonal paramo vegetation in the lower part of the paramo belt. Upper andean forests are marked with an asterisk. For the puna climate diagram of Pampa Galeras (4000 m) of Fig. 3p mean annual precipitation is 822 mm and there are 4, resp . 3.2 months yearly with precipitation exce eding 50 resp. 100 mm. The duration of the wate rdeficit is 4.5 month. The zonal puna grassland consists of spaced bunches of Festuca species mainly (Tovar- Serpa 1973).

N I V A L

L T

UPPER SUPER PARAMO LOWER

SUPERPARAMO

n~ro o o

UPPER

Ooo

(21)a _{!:) 0000

GRASS PARAMO

LOWER

GRASS PARAMO

0 0

bamboo-

DWARF SHRUB

bunchgrassparamo

0 0

0 9 12

6 10

0 0 0 0 0 0 0

0 0

0 0 0 0

(closed)

paramo

o 0

bunc'figrass

bamboo-

17:\a 0 P aramo \.:;:.1 0

PARAMO number of ~IOOmm humid monthsi>SOmm

0 0 0

(op~n)

2 6

:H;-o;.,~c~t

Fig. 81. Tentative distribution of bamboo-, b amboo-bunchgrass- and bunchgrass paramos in the study area in relation to the number of humid and very humid months (as based on Fig. 3 and 79) and altitudinal zones . (bamboo paramo and bamboo-bunchgrass paramo: community 10-13; bunchgrass paramo: community 14-20)

5000 m

V A L

(Sierra

alt.

Z 0

5000m

Nevada del Cocuy)

all. : : ;

: :

4500

-4000

~CD

: arid

. ? ;

35oo

~CD

3000

3500-

速

;humid ?

速

3000

速速 SHRUB PARAMO

DWARF SHRUB PARAMO

LOWER BUNCHGRASS PARAMO

BAMBOO PARAMO

UPPER t--=0"-R'-'-Y--"'----'-'H..::.U;....cM.:..:I0'----i BUNCH SUPER PARAMO GRASS PARAMO

Fig. 82. Altitudinal distribution or the zonal communities of the paramo vegetation in the Colombian Cordillera Oriental. The community numbers refer to those used in the present study.

Fig. 83. Schematic sketch of spatial distribution of zonal and azonal lower bunch grass paramo communities on El Tabl6n(c . 3750 m), north of the Laguna Verde, NW of Neusa . 100~------------------------------------------------~

bamboos present

bamboos absent a zonal

~ ®

70 ~

·a Vl

c::

~so

.::£

0 ..0

40 steep slopes

(.)

E :::)

.c.

(.)

@ @)

N Vl Vl

c::

.::£

®® @)

(.)

.c. 10 c::

dry

@ @:@i~@ humid

Fig. 84. Mean thickness of zonal humic black soil in em in sample plots of various zonal communities of the open paramo vegetation of the study area in relation to degree of moisture. Shallow soils are often brownish, or they lack humic content as do true superparamo communities.

TOP SOIL pH OF ZONAL PARAMO COMMUNITIES CORDILLERA ORIENTAL,COLOMBIA pH

-pH

6.5-

6.5

- 6.0

6.0

-5.5

1'7'\

®® ®

x@l

@®

DWARF SHRUB PARAMO

5.0-

@ 4.5-

4.0

SHRUB PARAMO

chloa ~

5.5-

IQ§®

Lorenzo~

-5 .0

-4.5

LOWER BUNCH GRASS PARAMO

4.0

BAMBOO PARAMO

UPPER BUNCH GRASS PARAMO

SUPERPARAMO

Fig . 85. Top soil pH of the zonal communi ti es of the paramo vegetation in the Colombian Cordillera Oriental . The community numbers refer to those used in the present study.

mega- macro- meso- micronanolep tabryophyllous phyllous phyllous phyllous phyllous phyllous phyllous

NIVAL BELT

SUPER PAR AM 0

upper lower

GRASS PARAMO

upper lower

SUBPARAMO

upper lower

ANDEAN FOREST

upper lower

0 •• 0

•0 • @•

& r.lil

Zonal bamboo (black symbols) and other grass species (open symbols) Dominant species are underlined .

bamboo species: ~

NeuroZepis aperta NeuroZepis aristata @ Chusquea scandens e SwaUenochZoa tesseZata and SWaZZenochZoa weberbaueri -e- AuZonemia trianae

~ e

other grass species revo l utely l eaved bunches: mainly 0 CaZamagrostis effusa (and Festuca cf_ doZichophyZZa) blades + flat, strongly sheathing tufts: o Agrostis boyacensis and

0 CD

Agrostis haenkeana Ag~stis brevicuZmis SporoboZus ZasiophyUus Aciachne puZvinata (bryophyllously leaved cushions)

mega - macro- meso- micronanoleptabryophyllous phyllous phyllous phyllous phyllous phyllous phyllous

NIVAL BELT

SUPER PARAMO

upper lower

GRASS PARAMO

upper lower

SUBPARAMO

upper lower

ANDEAN FOREST

upper lower

Zonal shrub & dwar fshrub in humid (black symbols) and dry (open symbols) c limates Predominant species of wet side of the mountains ~

Eupatorium (=Ageratina ) tinifoZium

no zodal shn:b ~

...... A

L &. 6

,0,.

Predominant species of dry side of the mountains Loricaria compZanata (wet and dry side) Pernettya prostrata var. prostrata

Fig. 86. Leaf-size cha r ac t ers of predominant graminoid (A) and woody species (B) of the zonal paramo vege tation of the Cordillera Oriental, Colombia. Leaf-size c lasses are according to Raunki aer (1916), except for the bryophyllous class, which is accor d ing to Barkman ( 1979). Herbaceous dicot species were not considered. The grass paramo contains no zonal shrub except in (azonal) pockets. In the superparamo th er e i s no pronounced difference in woody spec i es between wet and dry mountain si des. The c limatic differences in this zone are more apparent in herbaceous species.

alt.

m 4800

B E L

A L

alt .

m 4800

a b

4500

1 4000

I :

45 00

II I I

:: II II

3500

II II II

I I I

II II

I I! II

" II

I I I

II II

I I I

I I I I

4000 a

II II

I "~ .

"II

I I

II II

II II II II

I I I

3000

N II

II II

II'

I I I

I 29

30 31 32 33 34

Ditri cho -lsoetion pH

3638

39 40

41 42

43 44 45 46

limosel- Pot ameto- Junco - other aq uat ic Myrioph. Eleochar.m commun ities leteo

3000

48 49 50 51 52 53 54 55 56 57 58 59

61 62 63 64 65 66

67 68 69 70

Marchanti o - Epi lob ieta lia

Dritrophio Wern enetalia

Sph agnum bogs

7.6

6. 0

5.0

. .

7.6

7.0

3500

l .

7.0

6. 0

I I I

5.0 I

4.0

*29

30 31 32 33 34

*3940*

4142

*4546

484950 515253545556575 8 59

6162 63646566

67686970

Fig . 87. Altitud inal distribut ion and pH r ange ( t op"s oi l /water x ) of aquat i c commun i t ies, reedswamp, mire and f l u sh vege t a tion , cushionbb g and Sphagnum bog in t h e paramo s of t h e study area .

0 0 0

...,

..:

---------

i=::

~ a~

- (..) - flj - a~ - ll)

g;-

---------

1-.

-------------

-.J

ltJ

Q')

C) "'(

ll)

1-ll)

Q::

~ Lt.. ~

::: ;J,

Lt..

Q::

~ C)

:;:

-.J

:;::

;;;

:::

g: :8

:;;

~ ~

;:, :;: 1ii

Ill

:;: Q) ::::::> Q::

~ Q::

::l

:;:

Q::

:e :::

•

"'(

>. u

a.-

:::

ll)

E-

:J ~ .~ to

;;

::t

('·---:.:

.<::.

:;:

1ii

ct. -.J

a ~

1'\J

"'(

-.a--o-

;::

0 0

...,

U')

0 0 0

...,

0 0

U')

(")

0 0 0

lri

(")

Fig. 8R. Altitudinal distribution and pH range of the topsoil in a zonal paramo dwarf forests, meadows and other a zonal communities of the study area.

·v------ :;,, . . __ _ _ _ _ _ _ __

ISOETETEA :::BE--------------- •

·v

CHARETEA

~=======·"cr:=============:~

Ll MOSELLETEA

-------- ~---·v ============:=:::J "'

POTAMETEA

"'~-

::J

Fig. 89.

Altitudinal distribution of Isoetetea, Charetea, Limoselletea and Potametea in the Colombian Cordillera Oriental and in the Bolivian Andes.

gravel

sand

clay

peat

gyttja

SUPERPARAMO

@ 0subass. typicum lsoetetum @ lsoetetum karsteni i

SOC!Oe

@bditrichetosum

lsoetetum @cleefii 2 lsoetetum andicolae

GRASSPARAMO

I so e t e t u m @)a a var. of Drepanocladus ex ann ulatus

@ab 4

PARAMO D IT R I

glacial is

palmeri

SUB-

@ lsoetetum

var.of Sphagnum cuspidatum

CH0

0 E T I 0 N

Fig. 90 .

Distribution of syntaxa of the Ditricho-Isoetion in the study area in relation to altitude and substrate.

(j)

CIJ

•.-l

PARAMO POND VEGETATION

(j)

• .-l

CIJ

s;::l

ALTITUDINAL ZONES PARAMOS

.j.J

(j) .j.J

(j)

0 CIJ

SUPERPARAMO GRASS PARAMO SUBPARAMO

Paramo pond species Isoetes

Lirnosella australis

-1-.J CIJ

;::l

cop..

:>.

;::l .j.J CO · .-l

rl rl

(j) CIJ

s;::l

.j.J

(j) (j)

rl rl

·.-l

•.-l

gyttja

111111111 1111 111111

Elatine cf. chilensis

substrates silt clay

soc~a

Tillaea paludosa

upper lower upper lower upper lower

sand

CIJ

1111 1111

IIIII 1111

IIIII IllIll

Fig . 91 .

A. Alti t udinal distribution of the Isoetetum sociae (31), the Limosella australis community (38) and the Tillaeetum paludosae (36) in the paramos of the Co l ombian Cordillera Oriental. B. Distrib.u tion in relation to substrate of various amphibious vascular

species in the paramos of the study area.

w 0

APPENDIX 2 +)

ALPHABETIC LIST OF THE REFERRED TROPICAL ANDEAN TAXA WITH THEIR AUTHORITIES

Acaena (Rosaceae) A. cylindristaahya Ruiz Lopez et Pavon A. elongata L. Aaaulimalva (Malvaceae) A. purdiei (A. Gray) Krapov . Aahyroaline (Compositae) A. lehmannii Hieron . Aaiaahne (Gramineae) A. pulvinata Benth . Acnistus (Solanaceae) A. quitoensis (Hook.) Hunz. Ageratina fide Eupatorium Agrostis (Gramineae) A. boyacensis Swallen A. breviaulmis Hitchc. A. foliata Hook. f. A. haenkeana Hitchc . A. triahodes Roemer et Schultes Altensteinia (Orchidaceae) A. fimbriata H.B.K. A. leuaantha Reichb. f. A. paludosa Reichb. f. Aphanaatis (Compositae) A. ligulata Cuatrec. A. piloseZloides Cuatrec. Aragoa (Scrophulariaceae) A. abietina H.B.K. A. aupressina H.B.K. A. dugandii Romero A. lyaopodioides Benth. A. perez-arbelaeziana Romero +)

Araytophyllum (Rubiaceae) A. aaraaasanum (H.B.K.) Standley A. mutiaum (Wedd.) Standley A. nitidum (H.B.K.) Schldl. Arenaria (Caryophyllaceae) A. serpyllifolia L. A. venezuelana Briq. Asplenium (Polypodiaceae) A. aastaneum Cham. et Schldl. A. ~riphyZZum Presl Aulonemia (Gramineae) A. trianae (Munro) McClure Azolla (Azollaceae) A. fiZiauZoides Lam. AzoreZla (Umbelliferae) A. crenata (Ruiz Lopez et Pavon) Pers. A. auatrecasasii Mathias et Constance A. muZtifida (Ruiz Lopez et Pavon) Pers. A. pedunauZata (Sprengel) Mathias et Constance Baacharis (Compositae) B. caespitosa (Ruiz Lopez et Pavon) Pers. var. alpina (H.B.K.) Cuatrec. B. maarantha H. B.K. ssp. denticuZata Cuatrec . (ssp. ined.) B. prunifoZia H. B.K. B. revoluta H.B.K. B. rupicoZa H.B.K. var . orientaZis Cuatrec . B. triauneata (L. f.) Pers.

Names marked "ined." are as yet not validly published. They are not accepted by me for purposes of valid publication.

Befaria (Ericaceae) B. taahirensis Steyerm. Berberis (Berberidaceae) B. aretata Camargo B. goudotii Triana et Planchon B. sumapazana Camargo Bidens (Compositae) B. triplinervia H.B.K. Bleahnum (Blechnaceae) B. (Lomaria) loxense (H.B.K.) Hieron. Braahyotum (Melastomataceae) B. strigosum Triana Braahypodium (Gramineae) B. mexiaanum Link Bromus (Gramineae) B. lanatus H.B.K. B. unioloides H.B.K. Buaquetia (Melastomataceae) B. glutinosa Gleason Buddleia (Loganiaceae) B. lindenii Benth. Bulbostylis (Cyperaceae) B. tropiaales (Clarke) Britton Calamagrostis (Gramineae) C. bogotensis (Pilger) Pilger C. boyaaensis Swallen et Garc . -Barr . C. aoaratata (H.B.K.) Steudel C. effusa (H.B.K.) Steudel C. ligulata (H.B.K.) Hitchc . C. planifolia (H.B.K.) Trin . C. recta (H.B.K.) Trin. 'Calandrinia (Portulacaceae) C. aaaulis H.B.K. Calaeolaria (Scrophulariaceae) C. mexiaana Benth. C. penlandii Pennell

Callitriahe (Callitrichaceae) C. nubigena Fassett Cardamine (Cruciferae) C. afriaana L. C. bonariensis Juss. ex Pers . (=C. flaaaida Cham. et Schldl.) Carex (Cyperaceae) C. aautata Boott C. bonplandii Kunth C. aonferto-spiaata Boeckeler C. feaunda Steudel C. grandiflora (nom.herb., US) C. jamesonii Boott C. peuaophila Holm C. piahinahensis H.B.K. C. pygmaea Boeckeler C. tristiaha Spruce ex Boott Castilleja (Scrophulariaceae) C. fissifolia L. f. C. integrifolia L. f. Castratella (Melastomataceae) C. piloselloides (Bonpl . ) Naudin C. rosea Gleason Centropogon (Lobeliaceae) C. ferrugineus (L . f.) Gleason Cerastium (Caryophyllaceae) C. imbriaatum H.B.K . C. subspiaatum Wedd. Cestrum (Solanaceae) C. parvifolium Willd. Chaetolepis (Melastomataceae) C. miarophylla (Bonpl.) Miq. Chusquea (Gramineae) C. saandens Kunth Cinna (Gramineae) C. poaeformis (H.B.K.) Scribner et Merr. w 0

Clethra (Clethraceae) C. fimbriata H.B.K. Colobanthus (Caryophyllaceae) C. quitensis (Bartl.) H.B.K. Conyza (Compositae) C. uliginosa (Benth.) Cuatrec. Coriaria (Coriariaceae) C. ruscifolia L. ssp. microphylla (Poir.) L.Skog Cortaderia (Gramineae) C. nitida (H.B.K.) Pilger C. sericantha (Steudel) Hitchc. Cotula (Compositae) C. minuta (L. f.) Sweet Crassula (Crassulaceae) C. bonariensis Cambess . Cyperus (Cyperaceae) C. rivularis var. lagunetto (Steudel) O'Neill Cystopteris (Polypodiaceae) C. fragilis (L . ) Bernh. Danthonia (Gramineae) D. secundiflora Presl Diplostephium (Compositae) D. alveolatum Cuatrec. D. colombianum (Cuatrec.) Cuatrec. D. eriophorum Wedd. D. glutinosum Blake D. glutinosum var. cocuyanum Cuatrec. D. heterophyllum Cuatrec. D. huertasii Cuatrec. D. juajibioyi Cuatrec . D. lacunosum Cuatrec. D. phylicoides (H.B.K.) Wedd . D. revolutum Blake D. rhomboidale Cuatrec . D. ritterbushii Cuatrec. D. rupestre (H.B.K.) Wedd. D. schultzii Wedd.

Disterigma (Ericaceae) D. empetrifolium (H.B.K.) Drude Distichia (Juncaceae) D. muscoides Nees et Meyen (=D. tolimensis Benth. et Hook.) Draba (Cruciferae) D. hammenii Cuatrec. et Cleef D. lindenii (Hook.) Planchon D. litamo Uribe D. pamplonensis Planchon et Linden Drymaria (Caryophyllaceae) D. villosa Cham. et Schldl. ssp. paramorum (Blake) ~uke Dryopteris (Polypodiacea路e) D. paleacea Christ. Dysopsis (Euphorbiaceae) D. glechomoides Muell. Arg. Elaphoglossum (Polypodiaceae) E. engelii (Karsten) Christ . E. lindenii (Bory ex Fee) Moore Elatine (Elatinaceae) E. chilensis Gay Eleocharis (Cyperaceae) E. acicularis (L.) Roemer et Schultes E. macros~achya Britton E. stenocarpa Svenson Elodea (Hydrocharitaceae) E. potamogeton Espin. Epidendrum (Orchidaceae) E. chioneum Lindley E. erosum Ames et Schweinf. Epilobium (Onagraceae) E. denticulatum Ruiz Lopez et Pavon E. mePidense Hausskn.

Erigeron (Compositae) E. ohionophilus Wedd. E. eouadoriensis Hieron. E. paramensis Aristeg. et Cuatrec. Eriooaulon (Eriocaulaceae) E. miorooephalum H.B.K. Eriosorus (Hemionitidaceae) E. hirsutulus (Mett . ) A. Tryon Eryngium (Umbelliferae) E. humboldtii F. Delaroche E. humile Cav. Esoallonia (Escalloniaceae) E. myrtilloides L. f. var. myrtilloides Espeletia (Compositae) E. annemariana Cuatrec. E. annemariana var. rupioola Cuatrec. E. arbelaezii Cuatrec. E. argentea Humb. et Bonpl . E. azuoarina Cuatrec. E. barolayana Cuatrec. E. boyaoensis Cuatrec. E. braohyaxiantha Diaz Pi edr . E. ohooontana Cuatrec. E. oleefii Cuatrec. E. oongestiflora Cuatrec. E. oonglomerata A.C. Smith E. ourialensis Cuatrec. E. disooidea Cuatrec. E. grandiflora Humb. et Bonpl . ssp. grandiflora E. grandiflora ssp. boyaoensis Cuatrec. E. inoana Cuatrec. E. jaramilloi Diaz Piedr . E. killipii Cuatrec. var. killipii E. killipii var. ohisaoana Cuatrec . E. lopezii Cuatrec.

E. lopezii var. major Cuatrec. E. miradorensis Cuatrec. E. murilloi Cuatrec. E. nemenkenei Cuatrec. E. oswaldiana Diaz Piedr. E. rositae Cuatrec. E. summapaois Cuatrec. E. tapirophila Cuatrec . Espeletiopsis (Compositae) E. colombiana (Cuatrec.) Cuatrec. E. oorymbosa (Humb. et Bonpl.) Cuatrec. E. garoiae (Cuatrec.) Cuatrec. E. guaoharaoa (Diaz Piedr.) Cuatrec. E. jimenez-quesadae (Cuatrec.) Cuatrec. E. muiska (Cuatrec.) Cuatrec. E. pleioohasia (Cuatrec.) Cuatrec. var. soootana Cuatrec . Eupatorium (Compositae) E. fastigiatum H.B.K. E. glyptophlebium Robinson E. gracile H.B.K. E. gynoxoides Wedd. E. theaefoliv~ Benth . Equisetum (Equisetaceae) E. bogotense H.B.K. Festuoa (Gramineae) F. breviaristata Pilger F. dolichophylla Presl Flosoaldasia (Compositae) F. hypsophila Cuatrec. Gaiadendron (Loranthaceae) G. punctatum (Ruiz Lopez et Pavon) G. Don (Rubiaceae) Galiuw G. canescens H.B.K. G. trianae Wernham w 0 w

Gaultheria (Ericaceae) G. anastomosus (Mutis ex L. f . ) H. B. K. G. ramosissima Benth . G. rigida H. B. K. Gaylussacia (Ericaceae) G. buxifolia H. B. K. Gentiana (Gentianaceae) G. sedifolia H. B. K. Gentianella (Gentianaceae) G. corymbosa (H. B. K. ) Weaver et Rudenb . G. dasyantha (Gilg) Weaver et Rudenb . G. nevadensis (Gilg) Weaver et Rudenb . Geonoma (Palmae) G. weberbaueri Dammer ex Burret Geranium (Geraniaceae) G. confertum Standley G. multiceps Turcz . G. sibbaldioides Benth . var . elongatum R. Knuth G. subnudicaule Turcz . Gnaphalium (Compositae) G. antennarioides DC . G. meridanum Aristeg . G. spicatum Lam. Grammitis (Ctenopteris) (Polypodiaceae) G. flabelliformis (Poir . ) J . Smith G. meridense (Kl . ) Morton G. moniliformis (Lag . & Sw. ) J . Smith G. variabilis (Mett . ) Morton Gratiola (Scrophulariaceae) G. bogotensis Cortes G. peruviana L. Greigia (Bromeliaceae) G. mulfordii L. B. Smith Gynoxys (Compositae) G. albivestita Cuatrec . G. paramuna Cuatrec . G. pendula Schultz-Bip . ex Wedd .

w 0

G. G. G. G.

subcinera Cuatrec . subhirsuta Cuatrec . tolimensis Cuatrec . trianae Hie ron.

Halenia (Gentianaceae) H. gigantea Allen Hesperomeles (Rosaceae) H. goudotiana Killip H. lanuginosa Rul:z Lopez et Pavon Hieracium (Compositae) H. avilae Zahn Hinterhubera (Compositae) H. columbica Schultz-Bip . ex Wedd . Hydrocotyle (Umbelliferae) H. bonplandii Richter H. gunnerifolia Wedd . H. hederacea Mathias H. ranunculoides L. f . Hymenophyllum (Hymenophyllaceae) H. karstenianum Sturm Hypericum (Hypericaceae) H. caracasanum Willd . ssp . cardonae (Cuatrec . ) N. Robson H. cuatrecasasii Gleason H. garciae Pierce H. goyanesii Cuatrec . H. graciliforme N. Robson (ined.) H. humboldtianum Steudel H. juniperinum H. B. K. H. jussiaei Planchon et Linden (= H. humboldtianum Steudel) H. lancifolium Gleason H. laricifolium Juss . ssp . laricifolium H. laricifolium ssp . laricoides (Gleason)N . Robson(ined . ) H. lycopodioides Triana et Planchon H. magniflorum Cuatrec .

H. mexicanum L. f. Juncus (Juncaceae) H. papillosum N. Robson (ined.) J. cyperoides Laharpe H. phellos Gleason J. echinocephalus Balslev H. pimeloides Planchon et Linden ex Triana et Pl anchon J. ecuadoriensis Balslev H. prostratum Gleason J. microcephalus H.B.K. H. sabiniforme Trev路. J. stipulatus Nees et Meyen H. selaginoides N. Robson (ined.) Lachemilla (Rosaceae) H. strictum Kunth H. tetrastichum Cuatrec. L. diplophylla (Diels) Rothm. H. thuyoides Kunth L. fulvescens (Perry) Rothm. H. trianae N. Robson (ined.) L. hispidula (Perry) Rothm. Hypochoeris (Compositae) L. hotosericea (Perry) Rothm. H. sessili[Zora H.B.K. L. mandoniana (Wedd.) Rothm. Hypsela (Campanulaceae) L. nivalis (H.B.K. ) Rothm. H. reniformis Presl L. pinnata (Ruiz Lopez et Pavon) Rothm. L. polylepis (Wedd.) Rothm. L. orbiculata (Ruiz Lopez et Pavon) Rydb. Ilex (Aquifoliaceae) I. kunthiana Triana et Planchon L. tanacetifolia Rothm. L. venusta Rydb. Isoetes (Isoetaceae) Laestadia (Compositae) I. andico la (Amstutz) H.P. Fuchs I. andina Hook. ex Spruce L. muscicola Wedd. (= I. triquetra A. Braun) Lemna (Lemnaceae) I. bischlerae H.P. Fuchs (ined.) L. minor L. I. boyacensis H.P. Fuchs (ined.) Lepidium (Cruciferae) L. bipinnatifoUum Desv. I. cleefii H.P. Fuchs I. glaciaUs Aspl. Lilaea (Liliaceae) I. karstenii A. Braun L. subulata H.B.K. I. killipii C. Morton Lilaeopsis (Umbelliferae) I. novo-granadensis H.P. Fuchs L. schaffneriana (Schldl.) Coulter et Rose I. palmeri H.P. Fuchs Limosella (Scrophulariaceae) I. socia A. Braun L. australis R. Br. L. lineata Gluck Jaegeria (Compositae) Lobelia (Lobeliaceae) J. hirta (Lag.) Less. L. tenera H.B.K. Jamesonia 路 (Polypodiaceae) Lorenzochloa (Gramineae) J. bogotensis Karsten L. erectifolia (Swallen) J. et C. Reeder J. goudotii c.. Chr. Loricaria (Compositae) L. complanata (Schultz-Bip.) Wedd . w 0

lJ1

Lourteigia (Compositae; Eupatorioideae) L. miarophyllum (L. f.) R. King et H. Robinson Luailia (Compositae) L. pusilla (H.B.K.) Hieron . LudWigia (Onagraceae) L. peruviana L. var. peruviana Lupinus (Papilionaceae) L. alopeauroides Desr. L. humifusus Benth . L. verjonensis C.P. Smith Luzula (Juncaceae) L. gigantea Desv. L. racemosa Desv. L. vulcanica Liebm. Lycopodium (Lycopodiaceae) L. contiguum Kl. L. crassum Humb. et Bonpl. ex Willd. L. cruentum Spring L. rufescens Hook. L. spurium Willd . L. thyoides H.B. Willd. (= L. complanatum L. var. tropiaum Spring) Lysipomia (Campanulaceae) L. muscoides Hook. f. ssp. simulans McVaugh L. sphagnophila Griseb. ex Wedd. ssp. minor McVaugh L. sphagnophila ssp. minor var. cocuyanus Cleef (ined.) Maaleania (Ericaceae) M. rupestris A.C. Smith Masdevallia (Orchidaceae) M. coriacea Lindley Miconia (Melastomataceae) M. andina Naudin M. chionophila Naudin

M. aleefii Uribe M. ligustrina Triana M. mesmeana Gleason var. jabonensis M. parvifolia Cogn.

0"\

Wurdack

M. salicifolia (Bonpl.) Naudin Mimulus (Scrophulariaceae) M. glabratus H.B.K. Monnina (Polygalaceae) M. saliaifolia Ruiz Lopez et Pavon Montia (Portulacaceae) M. fontana L. M. meridensis Friedrich Moritzia (Boraginaceae) M. lindenii (A. DC.) Benth. ex Gurke Muehlenbeckia (Polygonaceae) M. thamnifolia (H.B.K.) Meissner M. vulcaniaa Endl. Muehlenbergia (Gramineae) M. fastigiata (Presl) Henrard M. ligularis (Hackel) Hitchc. M. linearis (nom. herb. ?) Myrica (Myricaceae) M. parvifolia Benth. Myriophyllum (Haloragaceae) M. brasiliense Cambess. M. elatinoides Gaudich. Myrrhidendron (Umbelliferae) M. glaucesaens (Benth.) Coulter et Rose Myrteola (Myrtaceae) M. oxyaoaaoides (Benth.) Berg Nephopteris (Polypodiaceae) N. maxonii Lellinger Nertera (Rubiaceae) N. granadensis (Mutis ex L. f.) Druce

Neurolepis (Gramineae) N. aristata (Munro) Hitchc. Niphogeton (Umbelliferae) N. dissecta (Benth.) J.F. Macbr. N. fruticosa Mathias et Constance N. glaucescens (Kunth) J.F. Macbr. N. josei Mathias et Constance N. lingula (Wedd.) Mathias et Constance N. ternata (Willd. ex Roemer et Schultes) Mathias et Constance var. ternata Noticastrum (Compositae) N. marginatum (H.B.K.) Cuatrec. Odontoglossum (Orchidaceae) 0. lindenii Lindley Ophioglossum (Ophioglossaceae) 0. orotalophoroides Walt. Oreobolus (Cyperaceae) 0. obtusangulus Gaudich. ssp. rubro-vaginatus (Kuk.)T.Koyama Oreomyrrhis (Umbelliferae) 0. andioola (Kunth) Hook. f. Oreopanax (Araliaceae) 0. mutisianum (H.B.K.) Decne. et Planchon Oritrophium (Compositae) 0. ooouyense (Cuatrec.) Cuatrec. 0. limnophilum (Schultz-Bip.) Cuatrec. ssp. mutisianum (Cuatrec.) Cuatrec. 0. limnophilum ssp. nevadanum Cuatrec. 0. limnophilum ssp. punae Cuatrec. 0. peruv~anum (Lam.) Cuatrec. a. vahlii (Gaudich.) Cuatrec. Orthrosanthus (Iridaceae) 0. ohimboracensis (H.B.K.) Baker var. ohimboraoensis attoa (Piperaceae) 0. oenanthioides H.B.K.

Ourisia (Scrophulariaceae) a. musoosa Benth. Oxalis (Oxalidaceae) o. oornuta L. 0. medioaginea H.B.K. Oxylobus (Compositae) 0. glanduliferus (Schultz-Bip.) A. Gray Paepalanthus (Eriocaulaceae) P. alpinus Koern. P. a:adi cola Koern. var. villosus Moldenke P. oolumbiensis Ruhl. P. orassicaulis Koern. P. karstenii Ruhl. P. lodiouloides Moldenke var. floooosus Moldenke P. paramensis Moldenke P. pilosus (H.B.K.) Kunth Parietaria (Urticaceae) P. debilis Forster Paspalum (Gramineae) P. bonplandianum Fluegge Peperorma (Piperaceae) P. hartwegiana Miq. P. hispidula (Sw.) A. Dietr. P. miorophylla H.B.K. Pernettya (Ericaceae) P. hirta (Willd.) Sleumer P. prostrata (Cav.) DC. var. prostrata P. prostrata var. purpurea (Don) Sleumer Phyllaotis (Valerianaceae) P. rigida Pers. Pilularia (Marsileaceae) P. mandoni A. Braun Pinguicula (Lentibulariaceae) P. elongata Benj. w 0

-.J

PZagiocheiZus (Compositae) P. soZivaeformis DC. ssp. muZtifZorus Cuatrec. PZantago (Plantaginaceae) P. austraZis Lam. ssp. oreades (Decne.) Rahn P. rigida H.B.K . P. sericea H.B.K. ssp. argyrophyZZa (Decne.) Rahn P. tubuZosa Decne. Poa (Gramineae) P. paucifZora Roemer et Schultes PoZyZepis (Rosaceae) P. quadrijuga Bitter PoZypodium (Polypodiaceae) P. angustifoZium Sw . PoZystichum (Polypodiaceae) P. poZyphyZZum (Presl) Presl Potamogeton (Haloragaceae) P. aspZundii Horn af Rantzien (ined.) P. berteroanus Phil . P. drepanocZadoides Horn af Rantzien (ined.) P. iZZinoensis Morang P. strictus Phil. PotentiZZa (Rosaceae) P. heterosepaZa Fritsch Pterichis (Orchidaceae) P. gaZeata Lindley Pteridium (Pteridiaceae) P. aquiZinum (L . ) Kuhn PurpureZZa (Melastomataceae) P. grossa (L. f.) Cogn. Puya (Bromeliaceae) P. aristiguietae Lyman B. Smith P. bicoZor Mez P. goudotiana Mez P. hamata Lyman B. Smith P. santosii Cuatrec.' P. trianae Baker

RanuncuZus (Ranunculaceae) R. fZageZZiformis J.E . Smith R. ZimoseZZoides Turcz. R. mandonianus Wedd. R. nubigenus H. B.K. ex DC. R. peruvianus Pers. R. spaniophyZZus Lourt. Rapanea (Myrsinaceae) R. dependens (Ruiz Lopez et Pavon) Mez ReZbunium (Rubiaceae) R. hypocarpium (L.) Hemsley RhizocephaZum (Campanulaceae) R. candoZZei Wedd. Rhynchospora (Cyperaceae) R. macrochaeta Steudel R. paramorum Mora R. ruiziana (Boeckeler) Macbr. Ribes (Saxifragaceae) R. coZumbianum Cuatrec . Rubus (Rosaceae) R. eriocarpus Liebm. Rumex (Polygonaceae) R. acetoseZZa L. R. toZimensis Wedd. SaZvia (Labiatae) S. kiZZipiana Epling Satureja (Labiatae) S. nubigena (Kunth) Briq . Scirpus (Cyperaceae) S. catifornicus Britton S. inundatus Sprengel Senecio (Compositae) S. adgZaciaZis Cuatrec. S. andicoZa Turcz . S. cacaosensis Cuatrec. S. canescens (Humb. et Bonpl.) Cuatrec. S. canescens var. boyacensis Cuatrec. S. cZeefii Cuatrec .

w 0 ro

S. S. S. S. S. S.

cocuyanus (Cuatrec.) Cuatrec. flos-fragans Cuatrec. fZos-fragans fma. frigidophilus Cuatrec. formosus Wedd. gelidus Wedd. guadalupe Cuatrec. S. guantivanus Cuatrec. S. guicanensis Cuatrec. S. la.tifZorus Cuatrec. S. ledifolius (H.B.K.) DC. S. nitidus (H.B.K.) DC. S. niv.eo-aureus Cuatrec. S. pascui-andinus Cuatrec. S. pulchellus (H.B.K.) DC. S. pungens (H.B.K.) DC. fma. pulchelZus Cuatrec. S. ramentosus Cuatre_c. S. reissianus Hieron. S. rep ens DC. S. santanderensis Cuatrec. S. subruncinnatus Greenman S. summus Cuatrec. S. supremus Cuatrec. S. vaccinioides (H.B.K.) Schultz-Bip. S. vernicosus Schultz-Bip. ex Wedd. Sericotheca (Rosaceae) S. argentea (Mutis) Raf. ÂŁibthorpia (Scrophulariaceae) S. repens (Mutis ex L.) Kuntze Sigesbeckia (Compositae) S. orientalis L. Siphocampylus (Campanulaceae) S. columnae (L. f.) G. Don Sisyrinchium (Iridaceae) S. pusillum H.B.K. S. tinctorum H.B.K. S. trinerve Baker Solanum (Solanaceae) S. bogotense Dunal

Spiranthes (Orchidaceae) S. coccinea Garray S. vaginata (H.B.K.) Lindley ex B.D. Jacson Sporobolus (Gramineae) S. lasiophyllus Pilger Stachys (Labiatae) S. eZliptica Benth. Stellaria (Campanulaceae) S. cuspidata Willd. Stevia (Compositae) S. luaida Lag. var. oaxana (DC.) Grashoff SWallenochloa (Gramineae) S. tesselata (Munro) McClure Symplocos (Simplocaceae) S. theiformis (L. f.) Oken Ternstroemia (Theaceae) T. meridionalis Mutis TiUaea (Crassulaceae) T. paludosa Schldl. Tofieldia (Liliaceae) T. sessilifZora Hook. (= T. falcata Pers.) Ugni (Myrtaceae) U. myricoides Berg Urtica (Urticaceae) U. ballotaefolia Wedd. Utricularia (Lentibulariaceae) U. obtusa Sw. Vaaainium (Ericaceae) V. fZoribundum H.B.K. var. marginatum (Dunal) Sleumer V. fZoribundum var. ramosissimum (Dunal) Sleumer Valeriana (Valerianaceae) V. arborea Killip et Cuatrec. V. longifolia H.B.K.

V. V. V. V.

pavonii Poeppig plantaginea H.B.K. stenophylla Kil~ip triphylla H.B.K. (= V. mutisiana (Wedd.) Hoeck) V. vetasana Killip Vallea (Elaeocarpaceae) V. stipularis Mutis ex 1. f . Verbesinea (Compositae) V. baccharidea Blake Veronica (Scrophulariaceae) V. serpyllifolia L. Vesicarex (Cyperaceae) V. collumanthus Steyerm. Vicia (Papilionaceae) V. andicola H.B . K. Viola (Violaceae) V. humilis H. B. K. Weinmannia (Cunoniaceae) W. fagaroides H. B.K. W. rollotii Killip Werneria (Compositae) W. crassa Blake ssp . orientalis Cuatrec . W. humilis H.B.K. var. angustifolia Cuatrec. (var . ined .) W. pygmaea Gillies Xyris (Xyridaceae) X. acutifolia (Heimerl) Malme X. subulata Ruiz Lopez et Pavon

w 0

APPENDIX

3 LOCALITY AND HABITAT DATA RELEVES

* * ~~1~~~~=~==~g~~========~~g~£~==1££g1~~~===~=======================g1~~~====~~g~===~£~g~~££11~~~~=~= Ia Jb JC 5 6a 8 9 10 II 13 13a 17 17a 24 27 31 39 41 51 55 59 63 65 67 80 81 95 97 99 100 101 102 105 106 109 I 10 Ill

Dec. 16 /71 Dec. II /71 Dec.ll /71 Dec.14 /71 Jan.22 /72 Jan.22 /72 Jan. 24 /72 Jan.24 /72 Jan. 24 /72 Jan.24 /72 Jan.26 /72 Jan. 26 /72 Jan. 29 /72 Jan.28 /72 Febr. 10 /72 Febr.12 /72 Febr.24 /72 Febr.28 / 72 Febr.29 /72 March 7 /72 March 23 /72 April 12 /72 April 22 /72 April 22 /72 April 26 /72 May II /72 May II /72 May 25 /72 May 25 /72 May 26 /72 May 26 /72 June 8 /72 June 8 /72 June 9 /72 June 9 /72 June II /72 June I I /72 June I I /72

Cund. II II

Pal.: Buitrago Sum. Chisaca II

Meta II

Lag. la Guitarra

Cund. II

Boy II

Andabobos

Belen: Alto de las Cruces II Q. Minas II

II ·

II II II

Boy II

Gua Belen, Alto de Cruces Chisaca c.v. La Viga II

Nevado

II II

Q. los Sitiales

Cund.

Chisaca II

Pal.: Buitrago II

Neusa: La Guargua II

Pisva: El Cadillal II

II II

Calarca II

3580 3700 3750 3400 3425 3450 3420 3465 3465 3465 3550 3500 3635 3635 3715 3800 3845 3780 3850 3765 3685 3480 3350 3355 3460 3700 3660 3575 3580 3605 3620 3480 3500 3535 3535 3580 3580 3580

NNE

s s WSW N NW

s sw SE NE

sw s NW

sw s NW SE SE

s NE SE SE

274-286 153 174 220 829-849 874 916-944 945-956 957-959 1041-1072 1032-1033 1211-1233 1228 1557-1572/1577, 1578 1654-1678, 1686 1776-1782 2027-2035 2058-2060 2259-2271, 2273 2574-2585 2841-2871 2993-3002 3032-3056 3152-3153 3605-3623 3635-3637 4084-4095 4112-4117 4129-4152 4156-4172 4218-4233 4234-4247 4278-4 282 4285- 4289 4390-4394 4401-4406 4409-4416 *) A.M.Cl ee f e t al.

:> '1:1 '1:1 tTJ

s H

:X:

116 127 134 137 138 139 142 143a 144 145 147 148 149 152 153 154 156 157 159 160 161 161a 162 168 169 171

172 179 180 183 184 185 186 187 189 190 19oa 193 194 195 J97

June 14/72 July 6 /72 July 12 /72 Aug . 17 /72 Aug . 22 /72 Aug . 22 /72 Aug . 25 /72 Aug . 25 /72 Aug . 25 /72 Aug . 25 /72 Aug . 30 /72 Aug. 30 /72 Sep . l /72 Sep. 19 /72 Sep . 19 /72 Sep . l9 /72 Sep.25 /72 Sep . 25 /72 Sep . 26 /72 Sep.26 /72 Sep . 26 /72 Sep . 26 /72 Sep . 27 /72 Sep. 30 /72 Oct. 2 /72 Oct.3 /72 Oct.4 /72 Oct . 5 /72 Oct . 5 /72 Oct.5 /72 Oct. 7 /72 Oct . ? /72 Oct. 7 /72 Nov . 9 /72 Nov . 9 /72 Nov . 9 /72 Nov . 9 /72 Nov . IO /72 Nov . IO /72 Nov . IO /72 Nov.ll /72

Boy . Cund.

" " "

Pisva : Calarc1i Sum. : Alto de las Sop as Chisaca Pal. : Q. Piedras Gordas Chisadi

" " " " " " " " " " "

Boy .

" "

" " "

Valle Sta. Rosa

" "

Pal. : Lag . Sec a " Chingaza " Chuza " Chingaza " Lag . Sec a

Coc .: Lag . la Pintada Lagunillas la Pintada " Alto Valle Lagunilla " Lag . Cuadrada "

" "

Valle Lagunillas

" " " "

" " "

Lag . Pint ada

" " " "

Cund .

" " "

" "

" " "

Valle Bocatoma

" " " " "

Valle Lagunillas

" "

Neusa : Lag . Sec a

" "

" " " " "

" " "

Lag . Verde

3620 3845 3630 3400 3660 3680 3625 3625 3620 3650 3730 3730 3700 3740 3640 3640 3985 3890 4065 4060 4060 4060 3960 4390 4005 3980 4310 4280 4280 4205 3915 3920 3925 3640 3685 3700 3700 3685 3690 3695 3655

E WSW E SSE

s SSE

sw NNW WSW NE

w w sw s WNW

w NW

w w N SE NE

4493-4515 4818-4823 4939-4946 5152-5162 5183-5196 5197-5214 5259-5272 5286, 5217 5287-5299 5301-5303 5332-5338 5341 5373-5396 5468-5472 5354-5360 5477-5491 5524-5526 5528-5532 5575-5576 5578-5585 5587-5589 5590 5596-5609 5703-5704 5723-5733 5778-5789 5792-5796 5862-5867 5868-5881 5901-5911 5925-5934 5939-5944 5949-5950 6100-6106 6122- 6140 6141-6142 6177-6180 6182 6188-6190 6201 - 6218

w ,_. N

197a 200 2ooa 204 206 207 207a 213 219 223 234 235 236 239 240 247 248 253 253a 254 255 257 257a 257b 261 262 262a 263 263a 264 264a 264b 265 26sd 266 267 267a 270 271 274

Nov . 12 /72 Nov . !! /72 Aug . 19 /72 Nov . 12 /72 Nov . 13 /72 Nov . 13 /72 Nov . 13 /72 Nov . IS /72 Nov.17 /72 Dec.6 /72 Dec . 9 /72 Dec . 9 /72 Dec.9 /72 Dec . 10 /72 Dec . 10 /72 Dec . 14 /72 Dec . 14 /72 Dec. IS /72 Dec . IS /72 Dec. 16 /72 Dec . 16 /72 Dec . 16 /72 Dec . 16 /72 Dec . 16 /72 Dec. 18 /72 Dec. 19 /72 Dec . 19 /72 Dec . 19 /72 Jan . 7 /73 Jan . 9 /73 Jan . 9 /73 Jan . 9 /73 Jan . 9 /73 Jan . 9 t73 Jan . 9 /73 Jan . 9 /73 Jan.9 /73 Jan . 13 /73 Jan . 13 /73 Jan . 16 /73

Cund .

Neusa : Lag . Verde

" " " "

Boy .

" " "

" "

" " "

" " " "

" " "

" " " "

" "

Cund . Meta

If If

II,

Sum .

" " " "

" " " " "

" " " "

Cogua

" "

Sec a Rusia: Aislada

" "

" " " "

" La Aislada Lag . Agua Clara Negra

Pena Blanca

Lag . Negra/Pena Blanca Pen a Negra II

Los Charcos Lag . Primavera

" " " "

" "

Nevado

" "

3650 3700 3625 3695 3670 3675 3675 3680 3660 3565 3505 3515 3520 3935 3845 3725 3745 3745 3745 3720 3730 3775 3775 3775 3820 3800 3800 3810 3925 3510 3510 3510 3515 3500 3535 3535 3535 4015 4090 4130

6252-6256 WNW

ssw ssw s SE

SE NNW ENE NW NW

s s

WSW WSW WS\<J NW

sw sw w

6300-6301 6314-6320 6323-6329 6322 6394-6419 6527-6540 6740-6744 6875-6886 6887-6890 6891-6906 6988-7017 6980 7203- 7219 7289-7301 7308 7309- 7327 7331-7346 7362-7365 7467-7481 7485-7502 7505-7516 7532 7555-7562 7564 - 7569 7572 7573-7580

sw NE

7734-7761 7766-7767 7922-7935

w ..... w

275 276 277 278 279 281 282 286 289 291 292 292a 293 294 295 296 297 298 300 3ooa 300b 300c 301 304 305 309 314 316 317 319 320 321 322 323 326 327 328 330a 331a 332 333

Jan . 16 /73 Jan . 16 /73 Jan.17 /73 Jan. 17 /73 Jan. 17 /73 Jan . 18 /73 Jan. 18 /73 Jan . 19 /73 Jan . 20 /73 Jan . 21 /73 Jan. 23 /73 Jan. 22 /73 Jan . 23 /73 Jan . 23 /73 Jan . 24 /73 Jan. 24 /73 Jan . 24 /73 Jan. 24 /73 Jan . 24 /73 Jan.24 /73 Jan . 24 /73 Jan . 24 /73 Jan.26 /73 Jan . 26 /73 Jan.27 /73 Jan . 28 /73 Febr.26 /73 Febr.26 /73 Febr. 26 /73 Febr . 27 /73 Febr . 27 /73 Febr.27 /73 Febr . 27 /73 Febr.27 /73 Febr . 28 /73 Febr . 28 /73 March 1 /73 March I /73 March 1 /73 March 3 /73 March 3 /73