We study a model ecosystem by means of dynamical techniques from disordered systems theory. The model describes a set of species subject to competitive interactions through a background of resources, which they feed upon. Additionally direct competitive or co-operative interaction between species may occur through a random coupling matrix. We compute the order parameters of the system in a fixed point regime, and identify the onset of instability and compute the phase diagram. We focus on the effects of variability of resources, direct interaction between species, co-operation pressure and dilution on the stability and the diversity of the ecosystem. It is shown that resources can be exploited optimally only in absence of co-operation pressure or direct interaction between species.
@article{arxiv.0705.1523,
title = {Statistical mechanics and stability of a model eco-system},
author = {Yoshimi Yoshino and Tobias Galla and Kei Tokita},
journal= {arXiv preprint arXiv:0705.1523},
year = {2009}
}
Comments
23 pages, 13 figures; text of paper modified, discussion extended, references added