Regensburg 2013 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 31: Statistical Physics in Biological Systems III (joint with DY)
BP 31.6: Vortrag
Donnerstag, 14. März 2013, 16:15–16:30, H46
The effect of predator limitation on the dynamics of simple food chains — •Christoph Schmitt1, Stefan Schulz1, Jonas Braun1, Christian Guill2, and Barbara Drossel1 — 1Physics Department, TU Darmstadt — 2Institute for Zoology and Anthropology, University of Göttingen
We investigate the influence of competition between predators on the dynamics of predator-prey systems and of tritrophic food chains. Competition between predators is implemented either as interference competition, or as a density-dependent mortality rate.
With interference competition, the paradox of enrichment is reduced or completely suppressed, but otherwise the dynamical behavior of the system is not fundamentally different from that of the Rosenzweig-MacArthur model, which contains no predator competition.
In contrast, with density-dependent predator mortality the predator-prey system shows a surprisingly rich dynamical behavior. In particular, decreasing the density regulation of the predator can induce catastrophic shifts from a stable fixed point to a large oscillation. Furthermore, the model shows several other types of nonlocal bifurcations, the coexistence of several attractors, and different types of regime shifts. In tritrophic food chains chaos can occur in both models.