  The changes on abiotic features of ecosystems have rarely been taken into
account by population dynamics models, which typically focus on trophic and
competitive interactions between species. However, understanding the population
dynamics of organisms that must modify their habitats in order to survive, the
so-called ecosystem engineers, requires the explicit incorporation of abiotic
interactions in the models. Here we study a model of ecosystem engineers that
is discrete both in space and time, and where the engineers and their habitats
are arranged in patches fixed to the sites of regular lattices. The growth of
the engineer population is modeled by Ricker equation with a density-dependent
carrying capacity that is given by the number of modified habitats. A diffusive
dispersal stage ensures that a fraction of the engineers move from their birth
patches to neighboring patches. We find that dispersal influences the
metapopulation dynamics only in the case that the local or single-patch
dynamics exhibits chaotic behavior. In that case, it can suppress the chaotic
behavior and avoid extinctions in the regime of large intrinsic growth rate of
the population.

Populations and Evolution