DEcoupling Biodiversity dimensions In Tropical ecosystems – DEBIT

Global patterns of biodiversity are driven by a number of processes that can be analyzed by studying the turnover in species composition across sampled location (i.e. beta diversity). In theory, there are eight possible combinations of high versus low taxonomic ß-diversity, phylogenetic ß-diversity and functional ß-diversity, and a general predictive framework has only recently emerged to propose hypotheses linking the observed decoupling patterns to underlying mechanisms. In the DEBIT project, we aim at evaluating this predictive framework by testing spatially explicit hypotheses for the effect of geographical isolation and environmental dissimilarity on patterns of biodiversity. We will focus on analyzing biodiversity dimensions of aquatic ecosystems (river systems) in the tropical environment of French Guiana using two taxonomic groups: fishes and insects. We will use innovative community-level modeling to evaluate how human induced modifications affect different facets of biodiversity.