Self-organizing in spatial competition systems

This chapter examines cellular automaton models of sessile colonial organisms that compete for space and demonstrate intransitivity in competitive interactions. Comparisons of spatial (cellular automata) and non-spatial (difference equation) models of 3-species intransitive network reveal qualitatively different dynamics and highlight the importance of including spatial context in community models. The cellular automata demonstrate emergence of a rich variety of spatial pattern, with the scale and topology of pattern being dependent on species richness, network structure, the exact nature of overgrowth interactions, and often on initial percentage cover and spatial arrangement of individuals. For many models, pattern topology is robust to various forms and levels of disturbance. Species co-existence is sensitive to symmetry in both network structure and growth rates of species, and to the area of habitat patches. The minimum habitat area for co-existence of species in stable networks depends strongly on the scale and topology of the self-organising spatial pattern.