Spatial dispersal of species.

With few exceptions, spatial heterogeneity in ecological models has been largely ignored until relatively recently. The current upsurge in interest is partly due to cross-fertilization with other disciplines, particularly mathematics. Models of species interaction in which the species disperse by diffusion are mathematically similar to those that arise in chemical reaction-diffusion systems which have been proposed as a basis for morphogenesis. Reaction/species interaction-diffusion systems have been increasingly studied mathematically in the last 15 years; this work has unearthed interesting new phenomena which have been proposed as explanations for many long-standing ecological problems involving spatial movement and heterogeneity of species. This is a very brief introduction to some of the basic results and how they impinge on ecology.