Competition and evolutionary stability of plants in a spatially structured habitat.

摘要

The modelling of the population dynamics of 2 types of plants with limited dispersal living in a lattice structured habitat is described. Each site of the square lattice model was either occupied by an individual or vacant. Each individual reproduced to its neighbours. A criterion was derived for the invasion of a rare type into a resident type population, based on a pair-approximation method, in which the dynamics of average densities and the nearest neighbour correlations were considered. Based on this criterion, it was shown that, with a trade off between birth and death rates, the evolutionarily stable type was the one with the highest ratio of birth rate to mortality. If these types are different species, they form segregated spatial patternsin the lattice model in which intraspecific competitive interactions occurs more frequently than interspecific interactions. However, stable coexistence is not possible in the lattice model contrary to results from completely mixed population models.