Abstract booklet - gtö – Society for Tropical Ecology

64 PARALLEL SESSION | H IV | RAIN FOREST STRUCTURE & DYNAMICSPLENARY | KEYNOTE | HALL H III 65SPECIALIZATION OR GENERALIZATION? FUNCTIONALITY OF WOO-DY AND PALM REGENERATION IN A MONTANE GUAYANAN RAIN-FOREST, SIERRA DE LEMA, VENEZUELACristabel Durán-Rangel 1 , Stefanie Stefanie Gaertner 3 , Albert Reif 1 , LionelHernández 2 , José Ayala 21 University of Freiburg, Freiburg, DE, cristabel.duran@waldbau.uni-freiburg.de, 2 GuayananCentre for Ecological Research, Universidad Nacional Experimental de Guayana., Ciudad Guayana,VE, 3 Department of Renewable Resources, University of Alberta, Albert, CATUESDAY 12:45 Hall H IVIn forests light constitutes a gradient which plant species partition. The resourcespartitioning is one of the explanation for species coexistence in the tropics.Species have been classified depending on their tolerance to shadow in functionalgroups (FG) and are thought to be specialized to an certain range of thelight gradient.We hypothesize that if species are specialists, they are found in a limited rangeof the light gradient. On the contrary if species are generalists, they are ableto germinate, survive and grow under all light conditions and being similarlyabundant along the light gradient.We ask how varies the abundance of FG along the light gradient and which arethe species regenerating only in gaps.The light gradient was stratified in gap, gap border and closed-canopy forestwith 39, 23 and 16 plots of 20m² respectively. Presence of trees, shrubs, palmsand fern-trees was recorded and individuals identified to family, genera or specieslevel when possible. Species were classified in FG (pioneers, long-lived pioneers,partial shade tolerant and shade tolerant) based on their wood density(WD). WD is a strong tool for categorizing species in FG since it provides anindicative trait of their shade tolerance. Palms were classified in partial shadetolerant and shade tolerant based on their maximal heights at adult stage.Shade tolerant species (including palms) where the most abundant FG (range:54-74% of all species) in all the light gradient followed by partial shade tolerantspecies (also palms) (range: 17-31% of all species). Pioneers and long-lived pioneersrepresented below 10% of the species even in gaps. Gap, border andforest do not differ on abundance of long lived pioneers, shade tolerant species(also palms). They do differ in abundance of pioneers and partial shade tolerantspecies (also palms), specifically gap and border differed in relation to forest.The majority of species growing only in gaps were shade tolerant or partial shadetolerant. The floristic composition of gap and border is similar and differ tothe forest.We conclude that forest regeneration is generalist prevailing shade tolerantand partial shade tolerant species. Even thought the floristic composition offorest regeneration changes along the light gradient, the majority of the speciesare generalists having competence to germinate, survive and grow under awide range of light conditions.Keynote: Tuesday, 22 February, 14:25 | Hall H IIIKeynote speaker: Miguel VencesChair: Eckhard HeymannDIVERSITY ASSESSMENT OF MADAGASCAR’S AMPHIBIANS ANDREPTILES: MICROENDEMISM OF SPECIES AND PHYLOGEOGRAPHICLINEAGES, AND PERSPECTIVES FOR THEIR CONSERVATIONMiguel Vences, TU Braunschweig, Braunschweig, DE, m.vences@tu-bs.deMadagascar harbors a unique fauna of amphibians and reptiles, characterizedespecially by an extreme degree of endemism of 100% among the ca. 275amphibian and >90% in the ca. 360 reptile species. Intensive application ofintegrative taxonomy have revealed an astonishing amount of undescribedcandidate species - especially in amphibians where an additional 200—300candidate species were discovered by combining DNA barcoding, bioacousticanalyses and morphology. While DNA barcoding alone should not be used assole argument for erecting new species it provides an extremely valuable toolto accelerate the erection of candidate species hypotheses that subsequentlycan be substantiated or rejected by other data sets. Many of the newlydiscovered species appear to be geographically very restricted whereas otherare widespread over most of Madagascar. Species diversity and microendemismappear to be related, on one hand, to extrinsic factors like elevationalheterogeneity in northern Madagascar, and on the other hand to intrinsicfactors such as life history and body size. Given that the true bottleneck atpresent is not species discovery but taxonomic species description of Malagasyamphibians and reptiles, and considering the extreme rate of ongoing habitatdestruction in Madagascar, it will be crucial to include undescribed candidatespecies and phylogeographic lineages to develop objective recommendationsfor spatial conservation priority assessments.TUESDAY 14:25 Hall H IIIgtöSociety for Tropical Ecology | Gesellschaft für Tropenökologie e.V. Status and future of tropical biodiversity | Frankfurt, 21 - 24 February 2011gtö