Disturbance, interspecific interaction and diversity in metapopulations |
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Authors: | HAL CASWELL JOEL E COHEN |
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Institution: | Biology Department, Woods Hole Oceanographic Institution, Woods Hole MA 02543, U.S.A.;The Rockefeller University, 1230 York Avenue, New York NY 10021, U.S.A. |
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Abstract: | Metapopulation diversity patterns depend on the relations among the timescales of local biological interactions (predation, competition), the rates of dispersal among local populations and the patterns of disturbance. We investigate these relationships using a family of simple non-linear Markov chain models. We consider three models for interspecific competition; if the species are identified with early and late successional species, the models describe the facilitation, inhibition and tolerance models of ecological succession. By adding a third competing species we also compare transitive competitive hierarchies and intransitive competitive networks. Finally, we examine the effects of predation in mediating coexistence among competing prey species. In each model we find circumstances in which biotic or abiotic disturbance can increase both local and regional diversity, but those circumstances depend on the various timescales in the model in ways that arc neither obvious nor trivial. |
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Keywords: | Competition succession competitive hierarchies and networks predator mediated coexistence patch occupancy models Markov chains |
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