Habitat associations of ant species (Hymenoptera: Formicidae) in a heterogeneous Mississippi landscape.

Community assembly and the factors that influence it have long been a topic of interest to ecologists, but theory has yet to produce unequivocal evidence that communities assemble in predictable ways. The goal of this study was to document the relationship between ant communities and environmental variation between four habitat types. To accomplish this, ant communities and 16 environmental variables were sampled across four different habitat types in the Black Belt Prairie and Flatwoods regions in Mississippi. Furthermore, ant species were placed into functional groups for an analysis of the relationship between the assembly of ecological communities and variation in ecosystem function. A total of 20,916 ants representing 68 species was collected across the four habitat types. Nonmetric multidimensional scaling and analysis of covariance analyses both revealed three distinct ant communities, which can be characterized by habitat type: pasture, prairie, and woodland. Principle components analysis (PCA) simplified the 16 environmental variables into four principle components that explained 78% of the variation among sites. Results of multiple regression using the four PCA axes as predictor variables suggest that regional variation in soil structure, land cover type, and the presence of grazing have had major influences on ant community composition. Variation in flora and habitat architecture had smaller but significant effects on ant species diversity and functional group composition. Our results imply that restoration of native ant communities in disturbed habitats must consider how current disturbance regimens likely interact with the presence of Solenopsis to lower ant biodiversity.