Population dynamics in highly fragmented landscapes

Human action fragments the natural habitat of several species all around the world. Understanding the effects of fragmentation to ecosystems is key to elaborate the best policies to avoid species extinctions. Therefore, it is important to study how the populations and ecosystems respond to these kinds of changes in landscapes. In this work, we use numerical methods to simulate reaction-diffusion equations in artificial landscapes generated with different structural distributions while keeping the total amount of habitat constant. This guarantees we are observing phenomena caused by fragmentation per se. We discuss the net effects of fragmentation into the steady total population. In order to do that correctly, we established the correlation between fragmentation metrics with fixed amount of habitat, to ensure that conclusions are not biased by interdependencies of metrics. We have also analytically calculated the critical size to allow population growth for bidimensional landscapes within our model, with given symmetries. These results prove that habitat area is not the only factor when it comes to population settling, and hence patch shape matters. Recent explorations on our model revel the presence of different movement scales, intra-patch and inter-patches. Future prospects of this project are studying how fragmentation affects features of population spatial distribution and investigations about regimes of fragmentation that allow non-interactive (or weakly interacting) subpopulations to form. We will also explore consequences of fragmentation to communities.