Statistical mechanics and stability of a model eco-system

• Published in: arXiv.org
• Main Authors: Yoshino, Yoshimi, Galla, Tobias, Tokita, Kei
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 04.09.2007
• Subjects: Biodiversity; Dilution; Ecosystems; Order parameters; Parameter identification; Phase diagrams; Physics - Disordered Systems and Neural Networks; Physics - Statistical Mechanics; Quantitative Biology - Populations and Evolution; Stability; Statistical mechanics; System theory; Systems theory
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.0705.1523

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.