Resource partitioning among competing individuals and population persistence: an individual-based model

Abstract

Using classical models of population dynamics, Łomnicki analysed the effects of different functions of resource partitioning. His main conclusion is that the monopolisation of resources ensures the highest population persistence. The objective of the present paper is to examine if it is possible to obtain similar results by using individual-based models for describing dynamics of a single population. Population dynamics was analysed when: (1) resources are evenly partitioned among individuals; (2) competition is of the scramble type; (3) competition is of the contest type and (4) resources are monopolised. It was shown that individual-based models do not support Łomnicki's simple and unequivocal conclusions derived from classical models. Different kinds of resource partitioning cannot be arranged on a linear scale that would represent an increasing population persistence as measured by the mean extinction time of the population. Łomnicki's conclusion that the population in which a part of individuals monopolises the resources is most persistent has not been confirmed. It is evident that models of population dynamics with different functions for resource partitioning vary in their properties, but these differences do not concern the mean extinction time of the population but, above all, the ranges of the parameters for which the longest extinction times of the population are observed.