Why allometric scaling enhances stability in food web models
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It has recently been shown that the incorporation of allometric scaling into the dynamic equations of food web models enhances network stability if predators are assigned a higher body mass than their prey. We investigate the underlying mechanisms leading to this stability increase. The dynamic equations can be written such that allometric scaling influences these equations at three places: the time scales of predator and prey dynamics become separated, the energy outflow to the predators is decreased, and intraspecific competition is increased relative to metabolic rates. For five food web topologies and various network sizes (i.e., species richness), we study the effect of each of these modifications on the percentage of surviving species separately and find that the decreased interaction strengths and the increased intraspecific competition are responsible for the enhanced stability. We also investigate the range of parameter values for which an enhanced stability is observed.
KeywordsMetabolic theory Population dynamics Complexity–stability relation Time scale effect Interaction strength Intraspecific competition
C.G. is supported by the German Research Foundation (BR 2315/9-1). We are grateful for comments and help by Ulrich Brose.
- Cohen JE, Briand, EF, Newman, CM (1990) Community food webs: Data and theory. Springer, New YorkGoogle Scholar
- Dunne JA (2006) The network structure of food webs. In: Pascual M, Dunne JA (eds) Ecological networks: linking structure to dynamics in food webs. Oxford University Press, Oxford, pp 27–86Google Scholar
- Elton CS (1958) Ecology of invasions by animals and plants. Chapman & Hall, London.Google Scholar
- Koen-Alonso M (2007) A process-oriented approach to the multispecies functional response. In: Rooney N, McCann KS, Noakes DLG (eds) From energetics to ecosystems: the dynamics and structure of ecological systems. Springer, DordrechtGoogle Scholar
- Martinez ND, Williams, RJ, Dunne, JA (2006) Diversity, complexity, and persistence in large model ecosystems. In: Pascual M, Dunne JA (eds) Ecological networks: linking structure to dynamics in food webs. Oxford University Press, Oxford, pp 163–185Google Scholar
- Odum E (1953) Fundamentals of ecology. Saunders, PhiladelphiaGoogle Scholar
- Paine RT (1980) Food webs, linkage interaction strength, and community infrastructure. J Anim Ecol 49:667–685Google Scholar