Abstract booklet - gtö – Society for Tropical Ecology

188 SCIENTIFIC POSTER SESSION | FOYERSCIENTIFIC POSTER SESSION | FOYER189Topic: Ecological networks and ecosystem functioningGEOLOGICAL SUBSTRATE DETERMINES TREE SPECIES AND TRAITDISTRIBUTIONS IN AFRICAN TROPICAL MOIST FORESTSAdeline Fayolle 2* , Delicia Pino 1 , Vincent Freycon 2 , Maxime Réjou-Méchain 3 ,Michael Swaine 4 , Jean-Louis Doucet 5 , Nicolas Fauvet 2 , Charles Doumenge 2 ,Sylvie Gourlet-Fleury 2 , Bettina M. J. Engelbrecht 1,6contributed to the observed patterns of species and trait distributions in theregion. Experiments will be required to disentangle the effects of speciesspecificresource requirements for nutrients and/or water, from that of pasthuman disturbances on patterns of species and trait distributions in Africanmoist forests.*communicating author: adeline.fayolle@cirad.fr | http://www.coforchange.eu/1Department of Plant Ecology, University of Bayreuth, Bayreuth, DE, 2 CIRAD, Research Unit‘Goods and Services of Tropical Forest Ecosystems’, Montpellier, FR, 3 Laboratoire Evolutionet Diversite´ Biologique, Toulouse, FR, 4 Department of Plant & Soil Science, CruickshankBuilding, School of Biological Sciences, University of Aberdeen, Aberdeen, UK, 5 Laboratoirede Foresterie des Régions tropicales et subtropicales, Université de Liège, Gembloux, BE,6Smithsonian Tropical Research Inst, Apartado 0843-03092, Balboa, PAPresenter: Delicia Rayda Pino GarayWEDNESDAY | FOYERThe EU-funded project CoForChange1 aims at predicting the fate of Africantropical moist forests under conditions of global change. A prerequisite forsuch predictions is understanding the factors shaping tree species distributionunder past and current conditions. In this study we aimed at identifying thedeterminants of species distribution patterns at large spatial scales in the semievergreenforests of Central Africa and at testing whether tree species withsimilar distribution patterns share similar functional traits due to environmentalfiltering. We analyzed the distribution patterns of 31 common tree species in anarea of more than 700,000 km² covering the Central African Republic, Cameroonand the Republic of Congo based on forest inventory data for trees ≥ 30 cmin diameter in 56,445 0.5-ha plots. Spatial variation of environmental factorspertaining to climate, geology, topography and disturbance were quantifiedfrom maps and satellite records. Four key functional traits of tropical treespecies were calculated or extracted from the literature: maximum growth rate,wood density, leaf phenology and shade tolerance. The geological substrateturned out to be of preeminent importance in shaping species distributionpatterns. Two contrasting species groups emerged: absent on sandstone,and those reaching high abundance on sandstone. Species associated withsandstone showed a suite of functional traits indicative of a strategy of efficientresource conservation: they had slower growth rates, higher wood density andmore evergreen leaf phenology, and higher shade tolerance than species onother substrates. These results are consistent with the hypothesis that treedistribution is determined by species tolerance to low soil resource availability(nutrients and/or water) on sandy soils. Additionally, past human disturbance(slash and burn agriculture) concentrating on resource-rich soils may haveWednesday WEDNESDAY 16:00 | FOYER | FoyergtöSociety for Tropical Ecology | Gesellschaft für Tropenökologie e.V. Status and future of tropical biodiversity | Frankfurt, 21 - 24 February 2011gtö