Wednesday, August 5, 2009 - 8:40 AM

COS 63-3: Competition and coexistence in competitive metapopulations

Michael B. Bonsall, University of Oxford

Background/Question/Methods

The coexistence of competitors in heterogeneous landscapes depends on the processes of colonization, extinction and spatial scale. Rather than simply evaluating the outcome of interspecific competition in the traditional manner, the focus here is on both the local population dynamic and the regional metapopulation processes that might influence species coexistence. Using well-replicated time series of the interaction between two bruchid beetles (Callosbruchus maculatus, Callosbruchus chinensis) the qualitative and quantitative pattern of interspecific competition between the beetles is shown to be shaped by the structure of the metapopulations.

Results/Conclusions

In free-dispersal metapopulations, the global exclusion of the inferior competitor is  influenced more by the processes associated with extinction rather than low colonization ability. In limited-dispersal metapopulations, the coexistence of competitors is mediated by both Allee effects and life-history (colonization – competition) trade-offs.