Abstract
The rapid and widespread loss of biodiversity caused by human disturbances on the ecosystems of the world is a matter of growing concern. Examples of such disturbances include climate change, overexploitation of natural resources, invasion of alien species and destruction and fragmentation of natural habitats. The aims of the present project are to provide a theoretical basis for the identification of fragile community structures and keystone species and to investigate the structure and robustness of the post-disturbance communities. To accomplish this task we will parameterise models of natural and microcosm communities and also generate theoretical communities using the cascade, niche, nested hierarchy and assembly algorithms. These model communities will then be subjected to small and large press perturbations. The effect of the perturbations on the trophic structure of the communities (including species abundances, species composition and distribution of links) will be investigated using the recently developed community viability analysis. We will then analyse how such structural changes affect the stability properties of the communities (including their resilience, reactivity and resistance) by developing and performing sensitivity and elasticity analysis at the community level. We believe that the new approaches to be used here hold great promise for community oriented conservation biology by identifying fragile ecosystem structures and keystone species.
Sweden