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BP: Fachverband Biologische Physik

BP 35: Posters: Statistical Physics, Evolution, and Networks

BP 35.15: Poster

Donnerstag, 25. März 2010, 17:15–20:00, Poster B2

The effect of body mass and adaptive foraging on food web robustness — •Lotta Heckmann, Christian Guill, and Barbara Drossel — Institut für Festkörperphysik, TU Darmstadt

Revealing the mechanisms promoting the stability of complex food webs remains a challenge for theoretical ecologists. One apparently stabilizing factor identified recently is the incorporation of allometric scaling, i.e., the influence of the body mass of a species on its metabolic rate, into the differential equations of population dynamics. By this, predator-prey interaction rates become body-mass dependent. Another mechanism contributing to the stability of food webs is adaptive foraging, that is, the capability of predators to focus on more profitable prey.

We numerically investigated the impact of the combined effects of allometric scaling and adaptive foraging on the robustness of food webs, considering different time scales of adaptation (evolutionary vs. behavioural changes) and different predator-prey body mass ratios. Our simulations include nonlinear population dynamics equations with Holling type II functional responses and intraspecific competition. The simulations were performed for different stochastic network structures, such as random graphs or the niche model. Additionally, we analyze in more detail the mechanisms by which adaptive foraging stabilizes food webs by using modules of a small number of interacting species.