Spatial segregation of interacting species.

The distributional pattern formation of the populations of two competitive species in heterogeneous environments is analyzed. In the mathematical formulation, a non-linear dispersive force due to mutual interferences of individuals and an environmental potential function are introduced as a behavioral version of Morisita’s phenomenological theory of “Environmental density”. Mathematical analyses of effects of these forces give the result that the heterogeneity of the environment and the non-linear dispersive movements raise a spatial segregation of the populations of two similar and competing species and there is a possibility that this spatial segregation acts to stabilize the coexistence of two similar species, relaxing the interspecific competition.