Regensburg 2007 – scientific programme

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BP: Fachverband Biologische Physik

BP 1: Evolutionary and Population Dynamics

BP 1.6: Talk

Monday, March 26, 2007, 11:30–11:45, H43

The Stability and Structure of Model Food Webs with Adaptive Behavior — •Satoshi Uchida and Barbara Drossel — Institut für Festkörperphysik, Technische Universität Darmstadt, Hochschulstraße 6, D-64289, Darmstadt, Germany

We present results for the stability and structure of model food webs described by population dynamics and adaptive behavioural dynamics (adaptive foraging and predator avoidance). In particular the influence of the initial network topology (randomly connected or niche model), and the type of constraints on the adaptive behavior (linear or nonlinear) are investigated. We evaluated two kinds of stability, namely the proportion of species surviving after running population dynamics, and the species deletion stability, and we measured two types of network parameters - link density and trophic level structure. We show that the initial web structure does not have a large effect on the stability of food webs, but foraging behavior has a large stabilizing effect. It leads to a positive complexity-stability relationship whenever higher "complexity" implies more potential prey per species. The observed link density after population dynamics depends strongly on the presence or absence of adaptive foraging, and on the type of constraints used. We also show that the foraging behavior preserves the initial trophic level structure for random and niche webs, while the population dynamics destroys the initial trophic structure for random webs.