Insular Biogeographic Theory and Diffusion Models in Population Dynamics

We examine a class of mathematical models describing the effects of habitat size and geometry on community structure. We deduce spatial effects at the community level from mechanistic models for the population dynamics and dispersal of individual populations together with some minimal hypotheses about the distribution of growth and dispersal rates among those populations. We use the models to deduce species-area curves, and in that sense they provide an alternative to the dynamic equilibrium theory of island biogeography introduced by MacArthur and Wilson. Since the models can explicitly incorporate various hypotheses about population dynamics and the nature and strength of interactions between species they permit a detailed analysis of how these hypotheses should affect community structure. We illustrate that point by contrasting the implications of different hypotheses in the context of refuge design.