Biodiversity loss and fragmentation - matrix effects and ecosystem consequences using a hyperdiverse Malagasy amphibian assemblage as an example

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Fragmentation is a process that may lead to the loss of biodiversity, i.e. to species-depleted communities in fragments. However, the effects of the loss of species may well go beyond the change in community properties of the animal groups in question (e.g. community structure) but may affect various ecosystem properties as well as ecosystem functioning. Hence, a fragmented landscape represents an appropriate system to study general community-ecosystem dependencies. Trophic interactions and the trophic structure of animal communities play important roles in most of these processes, and its study can provide direct insights into ecosystem functioning. The present project aims at understanding how patterns of amphibian diversity in a fragmented landscape and local extinctions depend on functional components of diversity, food web properties, morphological traits and phylogenetic distance. Furthermore, it will be analyzed if the composition and structure of the matrix (i.e. the non-forest habitat in which the fragments are embedded) are important drivers of changes in community and food web properties. This will be done by testing a set of hypotheses related to diversity pattern changes at the level of species, function, communities, and ecosystems. The proposed project will be conducted on anuran (frog) communities in the Ranomafana area of Eastern Madagascar, a montane rainforest ecosystem. This is a highly suitable model region with an unique amphibian diversity, where anuran systematics are largely settled and large molecular, phylogenetic, distributional and bioacoustic databases on these organisms exist and will be incorporated in this study. A variety of established field methods will be combined with state-of-the-art laboratory analyses. Food web structure will be comparatively assessed using stable isotopes, a wellestablished technique which, however, has so far not been applied to amphibiancommunities in such a comprehensive approach.