Omnivory and the stability of food webs.
The ecological concept of omnivory, feeding at more than a single trophic level, is formulated as an intermediate stage between any two of three classical three-dimensional species interaction systems-tritrophic chain, competition, and polyphagy. It is shown that omnivory may be either stabilizing or destabilizing, depending, in part, on the conditions of the parent systems from which it derives. It is further conjectured that the tritrophic to competition gradient cannot be entirely stable, that there must be an instability at some level of intermediate omnivory.
Vandermeer
John
J
Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA. jvander@umich.edu
D000818:Animals; D003163:Competitive Behavior; D004463:Ecology; D005247:Feeding Behavior; D020387:Food Chain; D005523:Food Supply; D008954:Models, Biological; D009747:Nutritional Physiological Phenomena; D011235:Predatory Behavior