Former Nason Lab PhD student Brad Duthie and colleagues have recently published a paper in American Naturalist investigating the mechanism of coexistence of multiple, ecologically similar fig wasp species coexisting on a single fig host. Here is a brief summary of the ecological issues addressed and the paper's findings.
Ecological communities in which organisms complete their life cycles on discrete ephemeral patches are common and often support an unusually large number of species. Explaining this diversity is challenging for communities of ecologically similar species undergoing preemptive competition, where classic coexistence mechanisms may not readily apply. Nonpollinating fig wasps develop within fig seeds and are community characterized by high diversity and preemptive competition. Because these nonpollinator species are often closely related, have similar life histories, and compete for the same discrete resources, understanding their coexistence is challenging given competitive exclusion is expected.
Empirical observations suggest that nonpollinating fig wasp species may face a trade-off between egg loads and dispersal abilities. Further, variation in interpatch distance between figs generates temporal variability in the relative benefit of fecundity versus dispersal. We use mathematical and individual-based modeling to show how a fecundity-dispersal trade-off can lead to coexistence. We discuss the implications of this coexistence mechanism for ephemeral patch systems wherein competition is strongly preemptive.
A. B. Duthie, Abbott, K. C., and Nason, J. D., “Trade-offs and coexistence: a lottery model applied to fig wasp communities.”, American Naturalist, vol. 183, pp. 826-841, 2014.