Movement strategies and population dynamics in heterogeneous environments

Abstract

The loss and fragmentation of natural habitats, often induced by human activities, have increasingly exposed species to environments consisting of mosaics of patches. The effects that such habitat changes will have on species and communities composition have become a central point in ecological research. Population dynamics in heterogeneous landscapes involve a complex interplay between movement and population growth. A vast wealth of empirical data have now shown the rich variety of movement strategies devised by species. It is not always clear, however, the long term effect of these strategies on the dynamics of ecological systems. In this project we planto investigate the population level consequences of individual movement strategies in heterogeneous environments. Mathematical modelling through reaction-dicussion equations and individual based simulations will be used. In particular, we initially plan to extend previous studies on a single and two species to communities modules of three species. The evolution of dispersal in non-homogeneous landscapes will also be analysed. Several techniques of analysis of partial dierential equations, both analytical and numerical, will be used in the study of the models. These include homogenization and reduction of a partial differential equation model to ordinary differential equations using mean occupancy times. The results obtained are expected to contribute to our understanding of the effects that modifications of natural habitats can have on species and help the development of strategies that can lessen the negative effect of habitat loss and fragmentation. (AU)