Urbanites Meet Urban Ants: Ant Species Distributions across the Urban Matrix in Ann Arbor, Michigan

Abstract

Urban Ecology is an increasingly important field as we look to preserve biodiversity and ecosystem services in urban spaces. In this thesis, I review the literature on diversity, abundance and species composition of ants in urban areas and through ant surveys examine questions of ant species richness and composition in the urban landscape. This study examines the effects of various urban matrix features at the habitat, local, and landscape levels on ant species richness and community composition. I surveyed ant richness at both the landscape and local scales by baiting and searching at twenty-seven equidistant sites within Ann Arbor city limits (landscape scale), and thirty sites within six city blocks northeast of Ann Arbor’s urban core (local scale). Ant species richness and ant species community composition were compared to landscape features (site proximity to rivers, parks, or urban core), local features (site proportion of vegetation, streets, or buildings) and habitat features (observed substrate or street direction). Local and landscape features were identified with various tools in ARC Geographic Information Systems Desktop and habitat feature were identified on site. A positive relationship was found between canopy cover and ant species richness. The composition of ant species within a sample site was more highly related to local habitat factors (such as bark or trash) than overall site composition, or proximity to urban or natural features. Furthermore, at the local scale species richness was associated with the nearest street city block. Our data suggest that small local changes in the habitat and block scale in urban landscapes are likely to alter ant species community composition. Specifically, changes in vegetation may increase species richness of ants and mediate the interaction between arboreal species and tramp species in the urban environments.