Abstract booklet - gtö – Society for Tropical Ecology

176 SCIENTIFIC POSTER SESSION | FOYERSCIENTIFIC POSTER SESSION | FOYER177Topic: Link for survival - Science and the conservation of tropicallandscapesTopic: Link for survival - Science and the conservation of tropicallandscapesDEPLETION OF FUNCTIONAL ATTRIBUTES IN TREESEEDLING ASSEMBLAGES IN A FRAGMENTED TROPICALRAIN FORESTINCREASED DOMINANCE OF PIONEER SPECIES ACROSSTREE ONTOGENETIC STAGES IN A FRAGMENTEDLANDSCAPE OF BRAZILIAN ATLANTIC FORESTSWEDNESDAY | FOYERWanessa Rejane Almeida 1 , Edgar Alberto do Espírito SantoSilva 1 , Felipe Pimentel Lopes de Melo 2 , Marcelo Tabarelli 21PPGBV, Dep. Botânica, UFPE, Recife, BR, wanereal@yahoo.com.br,2Departamento de Botânica, Universidade Federal de Pernambuco,Recife, BRForest fragmentation negatively affects tree regeneration in tropicalrain forests by reducing seed germination, altering seed rain andincreasing seedling mortality what leads to drastic changes intree seedling assemblages. We carried out a study in a severelyfragmented landscape of Brazilian northeast Atlantic forest to testif forest fragmentation can modified the structure, functional andtaxonomical composition of tree seedling assemblages. Speciesrichness and the proportion of species in nine functional groupswere analyzed by sampling 3900 seedlings (10-50 cm tall), 100 ineach of the 39 0.1-ha plots in two types of habitat: mature forestareas and small forest fragments (< 100 ha). The average and totalspecies richness was higher in mature forest than in small fragments.However, our results indicate that this loss of species is not random.In small fragments, pioneer, vertebrate-dispersed, and mediumsized-seededspecies showed an increase of 35.4%, 6.6%, and 27.1%in average proportion of species, respectively, and large-seededspecies a decrease of 59.7%. In addition, our results suggest thatthese changes in functional composition resulted in a taxonomicaldivergence between small fragments and mature forest. Weconclude that many old-growth forest species may not be able toregenerate in severely fragmented forest. Consequently, the futureflora of small fragments tends to diverge in terms of functional andtaxonomic composition in comparison with preserved mature forestareas.Wanessa Rejane Almeida 1 , Felipe Pimentel Lopes de Melo 2 ,Marcelo Tabarelli 21PPGBV, Dep. Botânica, UFPE, Recife, BR, wanereal@yahoo.com.br,2Departamento de Botânica, Universidade Federal de Pernambuco,Recife, BRForest fragmentation affects leads to a non-random loss of treespecies and forest remnants tend to retain only a limited subsetof their original flora. Our study compared the seedling, sapling,and adult communities in terms of richness, functional groupsand taxonomic composition. We aimed to evaluate whether theregenerating stand (i.e. seedling bank) is dominated by pioneers andsmall seeded species, and if there is any taxonomic differentiationamong seedlings, saplings, and adults. We sampled seedlings (allindividuals with less than 50 cm high, without evidence of vegetativepropagation) and both adults and saplings (individuals with DBH ≥ 2e ≤ 5 cm) were sampled in plots of 0.1 ha of 20 fragments between3.4 and 91.1 ha, in a severely fragmented landscape of Braziliannortheast Atlantic forest. In a set of pairwise comparisons we founddifferences on species richness between seedlings and adults withthe former being 27% lower than the later. We did not observeddifferences between seedlings and saplings, nor saplings and adults.Moreover, the seedling bank presented 10% more individuals and11% more small-seeded species than the sapling pool. An ordinationanalysis identified a significant taxonomic differentiation betweenontogenetic stages. Our results suggest that the regeneration poolpoints that this fragmented landscape tends to follow an alternativestate of succession, impoverished in number of species and biasedin functional and taxonomic composition when compared to laterontogenetic stages.Wednesday WEDNESDAY 16:00 | FOYER | FoyergtöSociety for Tropical Ecology | Gesellschaft für Tropenökologie e.V. Status and future of tropical biodiversity | Frankfurt, 21 - 24 February 2011gtö