Population Dynamics on Complex Food Webs

TL;DR

This paper analyzes the structure and dynamics of complex food webs using the niche model, introducing weighted overlap graphs to assess competition and stability, revealing that increased complexity reduces stability.

Contribution

It introduces weighted overlap graphs for competition analysis and provides new tests for the realism of synthetic food web models.

Findings

Weighted overlap graphs reveal competition among species.

Stability of food webs decreases as ecological complexity increases.

New methods for evaluating synthetic food web models.

Abstract

In this work we analyse the topological and dynamical properties of a simple model of complex food webs, namely the niche model. In order to underline competition among species, we introduce "prey" and "predators" weighted overlap graphs derived from the niche model and compare synthetic food webs with real data. Doing so, we find new tests for the goodness of synthetic food web models and indicate a possible direction of improvement for existing ones. We then exploit the weighted overlap graphs to define a competition kernel for Lotka-Volterra population dynamics and find that for such a model the stability of food webs decreases with its ecological complexity.