Dresden 2003 – scientific programme
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DY: Dynamik und Statistische Physik
DY 12: Statistical physics of complex networks
DY 12.5: Invited Talk
Monday, March 24, 2003, 12:30–13:00, G\"OR/226
Modelling food webs — •Barbara Drossel1 and Alan McKane2 — 1Institut für Festkörperphysik, TU Darmstadt, 64289 Darmstadt — 2Condensed Matter Theory Group, University of Manchester, M13 9PL, England
The debate over what stabilizes complex food webs has been an active one since May showed a quarter of a century ago that randomly connected models with Lotka-Volterra type dynamics become less stable with increasing complexity. Recently, it has been recognized that the presence of many weak links and the use of nonlinear growth rates that prevent predators from feeding efficiently on many prey at the same time stabilizes the dynamics of complex webs by reducing population fluctuations. In this talk, I will show that the implementation of these and other biologically realistic requirements allows the stepwise construction of large complex model webs that share many features with real food webs. In particular, several trophic layers and a large proportion of weak links emerge naturally, and need not be put into the system by hand, as is usually done.