The effects of plant species composition and habitat architecture on the organization of spider communities

Substantial empirical evidence in the ecological literature has demonstrated the importance of habitat structure in organizing animal communities. Species abundance and distributions have been shown to respond to a number of habitat structure parameters, including architectural complexity and structural heterogeneity (e.g.patchiness). Previous work in spider communities has indicated that spiders are no exception to this general pattern. Habitat structure is associated with spider species diversity, and different species within a community exhibit varying degrees of preference for specific habitat configurations. At the community level however, few, if any, studies have addressed the relationship between spider communities and plant species composition. This study assesses the relative influences of both habitat structure and plant species composition in three spider communities in East Tennessee.

Data from the current study suggest that the species composition of the vegetation plays a prominent role in spider community organization. Results from Mantel tests indicate a stronger relationship between spider and plant species assemblages than between spider assemblages and habitat configurations. While species diversity and densities in these communities were significantly predicted by habitat structure, six of the twelve abundant species considered individually were significantly associated with plant species composition. Only three species were associated with habitat. The plant species may have reflected variations in habitat structure at a finer scale than that captured by the specific habitat measurements made in this study.