Abstract
Destruction and fragmentation of natural habitats is predicted to cause unprecedented rates of species extinction in the near future. Here we will investigate the robustness of fragmented ecological communities, meta-communities, to local and global species losses. The response of ecological communities to species loss is most likely affected both by local processes (interactions among species coexisting within local communities) and regional processes (movement of species among local communities). Local processes are governed by the trophic structure (pattern of species interactions) of ecological communities and regional processes are governed by the spatial structure of the landscape (number and distance between habitat patches) and the dispersal abilities of species. The aim of the present project is to investigate how the trophic structure of local communities, spatial structure of landscapes and dispersal patterns of species affects the response of a meta-community to local and global losses of species. To accomplish this we develop a meta-community viability analysis that generates risk assessments: the probability that the number of species in an meta-community falls below some given level following the local or global loss of a species. We believe that the new approaches to be developed here hold great promise for identifying vulnerable ecosystems and keystone species.
Sweden