9623928 Morris Patchy and ephemeral resources such as rotting fruit are used by many species. Individuals that live in the same patch often compete very strongly, yet competitors may coexist regionally. Insects that live in rotting fruit frequently have highly aggregated intraspecific distributions, which may prevent competitive exclusion and maintain high species diversity. An aggregated distribution increases the frequency of intraspecific competition and leaves empty patches that may be colonized by other species. However the effect of aggregation has not been tested in the field, and may be swamped by other mechanisms. Pilot studies have found many species of insects with larvae that live in the rotting fruit of the tree Apeiba membranacae, and have aggregated distributions. These insects can be aggregated at three nested spatial scales: individual fruit, whole trees, and forest fragments. This research will experimentally test the importance of aggregation for coexistence in this system by documenting spatial patterns, measuring the strength and structure of competition, manipulating distributions of larvae, and investigating the interaction between predation and aggregation. This research will provide one of the first field tests of the importance of aggregation in promoting species coexistence in patchy and ephemeral resources. This research will also extend the existing theoretical models of coexistence due to aggregation to include multiple spatial scales.
