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Harvard Forest REU Symposium Abstract 2011
- Title: The Role of Competition in Shaping Local Ant Biodiversity and Community Dynamics
- Author: Kevin M Towle (University of Notre Dame)
- Abstract:
Patterns of global biodiversity follow a latitudinal gradient, with higher species richness being correlated with lower, tropical latitudes. A recent ant biodiversity study determined that forested sites follow this latitudinal trend, while open habitats do not. The goal of this study is to examine competition as a potential driver of local biodiversity, as interspecific competitive interactions have been shown to influence the community composition and species distribution within different habitats. We hand sampled ant species richness and nest abundance at 10 forest and 10 open habitat 5x5 m plots at the Harvard Forest LTER (Petersham, MA) and Myles Standish State Forest (Plymouth, MA). To evaluate competition strength, we conducted a behavioral assay of naturally occurring interactions using tuna baiting, and recorded the number of aggressive and neutral interspecific interactions. We found that open sites have a significantly higher species richness than forest sites, as estimated by the CHAO I Index. We also found that open sites have a significantly higher amount of aggressive competition than forest sites, despite there being no significant difference in relative ant nest abundance between sites. These results suggest that a higher degree of competition in local habitat types facilitates species coexistence and can increase species richness. Additionally, we suggest that community assembly is likely influenced by the level of competition between aggressive and neutral species.
- Research Category: Biodiversity Studies; Physiological Ecology, Population Dynamics, and Species Interactions
