Hostname: page-component-848d4c4894-ttngx Total loading time: 0 Render date: 2024-05-03T06:07:11.233Z Has data issue: false hasContentIssue false
  • English
  • Français

Do fungal pathogens drive density-dependent mortality in established seedlings of two dominant African rain-forest trees?

Published online by Cambridge University Press:  30 March 2010

Julian M. Norghauer ,
David M. Newbery ,
Leho Tedersoo  and
George B. Chuyong
Julian M. Norghauer*
Affiliation:
Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013, Bern, Switzerland
David M. Newbery
Affiliation:
Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013, Bern, Switzerland
Leho Tedersoo
Affiliation:
Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai Street, 51005 Tartu, Estonia
George B. Chuyong
Affiliation:
Department of Plant and Animal Sciences, University of Buea, P.O. Box 63, Buea, SW Province, Cameroon
*
1Corresponding author. Email: julian.norghauer@ips.unibe.ch
Get access Rights & Permissions [Opens in a new window]

Abstract:

Where one or a few tree species reach local high abundance, different ecological factors may variously facilitate or hinder their regeneration. Plant pathogens are thought to be one of those possible agents which drive intraspecific density-dependent mortality of tree seedlings in tropical forests. Experimental evidence for this is scarce, however. In an African rain forest at Korup, we manipulated the density of recently established seedlings (~5–8 wk old; low vs. high-density) of two dominant species of contrasting recruitment potential, and altered their exposure to pathogens using a broad-spectrum fungicide. Seedling mortality of the abundantly recruiting subcanopy tree Oubanguia alata was strongly density-dependent after 7 mo, yet fungicide-treated seedlings had slightly higher mortality than controls. By contrast, seedling mortality of the poorly recruiting large canopy-emergent tree Microberlinia bisulcata was unaffected by density or fungicide. Ectomycorrhizal colonization of M. bisulcata was not affected by density or fungicide either. For O. alata, adverse effects of fungicide on its vesicular arbuscular mycorrhizas may have offset any possible benefit of pathogen removal. We tentatively conclude that fungal pathogens are not a likely major cause of density dependence in O. alata, or of early post-establishment mortality in M. bisulcata. They do not explain the latter's currently very low recruitment rate at Korup.

Keywords

central Africadensity-dependencefungicideKorup National ParkMicroberlinia bisulcataOubanguia alataplant pathogensseedling mortalitytropical rain forest
Type
Research Article
Information
Journal of Tropical Ecology , Volume 26 , Issue 3 , May 2010 , pp. 293 - 301
Copyright
Copyright © Cambridge University Press 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

LITERATURE CITED

ARNOLD, A. E. 2008. Endophytic fungi: hidden components of tropical community ecology. Pp. 298–312 in Carson, W. P. & Schnitzer, S. A. (eds). Tropical forest community ecology. Wiley-Blackwell, Oxford.Google Scholar
AUBRÉVILLE, A. 1938. La Forêt Coloniale: Les forêts de l'Afrique occidentale française: Annales de l'Académie des Sciences Coloniales, v. IX. Société d'Editions Géographiques, Maritimes et Coloniales, Paris. 245 pp.Google Scholar
AUGSPURGER, C. K. 1983. Seed dispersal of the tropical tree, Platypodium elegans, and the escape of its seedlings from fungal pathogens. Journal of Ecology 71:759–771.CrossRefGoogle Scholar
AUGSPURGER, C. K. 1984. Seedling survival of tropical tree species – interactions of dispersal distance, light-gaps and pathogens. Ecology 65:1705–1712.CrossRefGoogle Scholar
AUGSPURGER, C. K. & KELLY, C. K. 1984. Pathogen mortality of tropical tree seedlings: experimental studies of the effects of dispersal distance, seedling density, and light conditions. Oecologia 61:211–217.CrossRefGoogle ScholarPubMed
AUGSPURGER, C. K. & WILKINSON, H. T. 2007. Host specificity of pathogenic Pythium species: implications for tree species diversity. Biotropica 39:702–708.CrossRefGoogle Scholar
BELL, T., FRECKLETON, R. P. & LEWIS, O. T. 2006. Plant pathogens drive density-dependent seedling mortality in a tropical tree. Ecology Letters 9:569–574.CrossRefGoogle Scholar
BRADLEY, D. J., GILBERT, G. S. & MARTINY, J. B. H. 2008. Pathogens promote plant diversity through a compensatory response. Ecology Letters 11:461–469.CrossRefGoogle ScholarPubMed
BURDON, J. J. & CHILVERS, G. A. 1982. Host density as a factor in plant disease ecology. Annual Review of Phytopathology 20:143–166.CrossRefGoogle Scholar
CONNELL, J. H. 1971. On the role of natural enemies in preventing competitive exclusion in some marine animals and in rain forest trees. Pp. 298–312 in den Boer, P. J. & Gradwell, G. (eds). Dynamics of populations. Centre for Agricultural Publication and Documentation, Wageningen.Google Scholar
DEMANOU, J., MONKIEDJE, A., NJINE, T., FOTO, S. M., NOLA, M., TOUGET, S. H. Z. & KEMKA, N. 2004. Changes in soil chemical properties and microbial activities response to the fungicide Ridomil Gold Plus Copper. International Journal of Environmental Research and Public Health 1:26–34.CrossRefGoogle Scholar
FRAZER, G. W, CANHAM, C. D. & LERTZMEN, K. P. 1999. Gap Light Analyzer (GLA) Version 2.0. Simon Fraser University, Burnaby, British Columbia and the Institute of Ecosystem Studies, Millbrook, New York. 36 pp.Google Scholar
FRECKLETON, R. P. & LEWIS, O. T. 2006. Pathogens, density-dependence and the coexistence of tropical trees. Proceedings of the Royal Society B 273:2909–2916.CrossRefGoogle ScholarPubMed
GALWEY, N. W. 2006. Introduction to mixed modeling: beyond regression and analysis of variance. John Wiley and Sons. Chichester. 366 pp.CrossRefGoogle Scholar
GILBERT, G. S. 2002. Evolutionary ecology of plant disease in natural ecosystems. Annual Review of Phytopathology 40:13–43.CrossRefGoogle ScholarPubMed
GILBERT, G. S. 2005. Dimensions of plant disease in tropical forests. Pp. 141–164 in Burslem, D. F. R. P., Hartley, S. E. & Pinard, M. A. (eds). Biotic interactions in the tropics: their role in the maintenance of species diversity. Cambridge University Press, Cambridge.CrossRefGoogle Scholar
GILBERT, G. S., HUBBELL, S. P. & FOSTER, R. B. 1994. Density and distance to adult effects of a canker disease of trees in a moist tropical forest. Oecologia 98:100–108.CrossRefGoogle Scholar
GIVNISH, T. J. 1999. On the causes of gradients in tropical tree diversity. Journal of Ecology 87:193–210.CrossRefGoogle Scholar
GREEN, J. J. & NEWBERY, D. M. 2001a. Shade and leaf loss affect establishment of grove-forming ectomycorrhizal rain forest tree species. New Phytologist 151:291–309.CrossRefGoogle ScholarPubMed
GREEN, J. J. & NEWBERY, D. M. 2001b. Light and seed size affect establishment of grove-forming ectomycorrhizal rain forest tree species. New Phytologist 151:271–289.CrossRefGoogle ScholarPubMed
GREEN, J. J. & NEWBERY, D. M. 2002. Reproductive investment and seedling survival of the mast-fruiting forest tree, Microberlinia bisulcata A. Chev. Plant Ecology 162:169–183.CrossRefGoogle Scholar
GROGAN, J. & GALVÃO, J. 2006. Factors limiting post-logging seedling regeneration by big-leaf mahogany (Swietenia macrophylla) in southeastern Amazonia, Brazil, and implications for sustainable management. Biotropica 38:219–228.CrossRefGoogle Scholar
HARMS, K. E., WRIGHT, S. J., CALDERON, O., HERNANDEZ, A. & HERRE, E. A. 2000. Pervasive density-dependent recruitment enhances seedling diversity in a tropical forest. Nature 404:493–495.CrossRefGoogle Scholar
HOOD, L. A., SWAINE, M. D. & MASON, P. A. 2004. The influence of spatial patterns of damping-off disease and arbuscular mycorrhizal colonization on tree seedling establishment in Ghanaian tropical forest soil. Journal of Ecology 92:816–823.CrossRefGoogle Scholar
JANZEN, D. H. 1970. Herbivores and the number of tree species in tropical forests. American Naturalist 104:501–528.CrossRefGoogle Scholar
JONES, E. W. 1956. Ecological studies on the rainforest in Nigeria: IV (Continued). The plateau forest of the Okumu Forest Reserve. Journal of Ecology 44:83–117.CrossRefGoogle Scholar
KARAGEORGOU, P., BUSCHMAN, P. & MANETAS, Y. 2008. Red leaf color as a warning signal against insect herbivory: honest or mimetic? Flora 203:648–652.CrossRefGoogle Scholar
LETOUZEY, R. 1968. Etude phytogéographique du Cameroun. P. LeChevalier, Paris. 508 pp.Google Scholar
MCCARTHY-NEUMANN, S. & KOBE, R. 2008. Tolerance of soil pathogens co-varies with shade tolerance of across species of tropical tree seedlings. Ecology 89:1883–1892.CrossRefGoogle ScholarPubMed
MONEY, N. P. 1998. Why oomycetes have not stopped being fungi. Mycological Research 102:767–768.CrossRefGoogle Scholar
MONKIEDJE, A., SPITELLER, M., MANIEPI, S. J. N. & SUKUL, P. 2007. Influence of metalaxyl- and mefenoxam-based fungicides on chemical and biochemical attributes of soil quality under field conditions in a southern humid forest zone of Cameroon. Soil Biology and Biochemistry 39:836–842.CrossRefGoogle Scholar
NEWBERY, D. M., ALEXANDER, I. J., THOMAS, D. W. & GARTLAN, J. S. 1988. Ectomycorrhizal rain-forest legumes and soil phosphorus in Korup National Park, Cameroon. New Phytologist 109:433–450.CrossRefGoogle Scholar
NEWBERY, D. M., SONGWE, N. C. & CHUYONG, G. B. 1998. Phenology and dynamics of an African rainforest at Korup, Cameroon. Pp. 267–308 in Newbery, D. M., Prins, H. H. T. & Brown, N. D. (eds). Dynamics of tropical communities. Blackwell Science, Oxford.Google Scholar
NEWBERY, D. M., ALEXANDER, I. J. & ROTHER, J. A. 2000. Does proximity to conspecific adults influence the establishment of ectomycorrhizal tree species in an African rain forest? New Phytologist 147:401–409.CrossRefGoogle Scholar
NEWBERY, D. M., CHUYONG, G. B., GREEN, J. J., SONGWE, N. C., TCHUENTEU, F. & ZIMMERMANN, L. 2002. Does low phosphorous supply limit seedling establishment and tree growth in groves of ectomycorrhizal trees in a central African forest? New Phytologist 156:297–311.CrossRefGoogle Scholar
NEWBERY, D. M., CHUYONG, G. B., ZIMMERMANN, L. & PRAZ, C. 2006a. Seedling survival and growth of three ectomycorrhizal caesalpiniaceous tree species in a Central African rain forest. Journal of Tropical Ecology 22:499–511.CrossRefGoogle Scholar
NEWBERY, D. M., CHUYONG, G. B. & ZIMMERMANN, L. 2006b. Mast fruiting of large ectomycorrhizal African rain forest trees: importance of dry season intensity, and the resource limitation hypothesis. New Phytologist 170:561–579.CrossRefGoogle ScholarPubMed
NEWBERY, D. M., PRAZ, C. J., VAN DER BURGT, X. M., NORGHAUER, J. M. & CHUYONG, G. 2010. Recruitment dynamics of the grove-dominant tree Microberlinia bisulcata in African rain forest: extending the light response versus adult longevity concept. Plant Ecology 206:151–172.CrossRefGoogle Scholar
NORGHAUER, J. M. & NEWBERY, D. M. (in press). Recruitment limitation after mast-seeding in two African rain forest trees. Ecology.Google Scholar
PETERMANN, J. S., FERGUS, A. J. F., TURNBULL, L. A. & SCHMID, B. 2008. Janzen–Connell effects are widespread and strong enough to maintain diversity in grasslands. Ecology 89:2399–2406.CrossRefGoogle ScholarPubMed
QUEENBOROUGH, S. A., BURSLEM, D. F. R. P., GARWOOD, N. C. & VALENCIA, R. 2007. Neighborhood and community interactions determine the spatial pattern of tropical tree seedling survival. Ecology 88:2248–2258.CrossRefGoogle ScholarPubMed
RICHARDS, P. W. 1996. The tropical rain forest. Cambridge University Press, Cambridge. 575 pp.Google Scholar
SONMEZ, S., KAPLAN, M., SONMEZ, N. K., KAYA, H. & UZ, I. 2007. Effect of both soil copper applications and foliar copper applications frequencies on macronutrients contents of tomato plants. Asian Journal of Chemistry 19:5372–5384.Google Scholar
TOSSELLI, M., BALDI, E., MARCOLONI, G., MALAGUTI, D., QUARTERIERI, M., SORRENTI, G. & MARANGONI, B. 2009. Response of potted pear trees to increasing copper concentration in sandy and clay-loam soils. Journal of Plant Nutrition 31:2089–2104.CrossRefGoogle Scholar
TURNER, I. M. 2001. The ecology of trees in the tropical rain forest. Cambridge University Press, Cambridge. 298 pp.CrossRefGoogle Scholar
WATT, A. S. 1919. On the causes of failure of natural regeneration in British oakwoods. Journal of Ecology 7:173–203.CrossRefGoogle Scholar
WATT, A. S. 1947. Pattern and process in the plant community. Journal of Ecology 35:1–22.CrossRefGoogle Scholar
WEBB, C. O. & PEART, D. R. 1999. Seedling density-dependence promotes co-existence of Bornean rain forest trees. Ecology 80:2006–2017.CrossRefGoogle Scholar
WENNY, D. G. 2000. Seed dispersal, seed predation and seedling recruitment of a neotropical montane tree. Ecological Monographs 70:331–351.CrossRefGoogle Scholar
WHITMORE, T. C., BROWN, N. D., SWAINE, M. D., KENNEDY, D., GOODWIN-BAILEY, C. I. & GONG, W. K. 1993. Use of hemispherical photographs in forest ecology: measurement of gap size and radiation totals in a Bornean tropical rain forest. Journal of Tropical Ecology 9:131–151.CrossRefGoogle Scholar
ZIMMERMAN, J. K, THOMPSON, J. & BROKAW, N. 2008. Large tropical forest dynamics plots: testing explanations for the maintenance of species diversity. Pp. 89–117 in Carson, W. P. & Schnitzer, S. A. (eds.). Tropical forest community ecology. Wiley-Blackwell, Oxford.Google Scholar