Ant Diversity in Pitcher-plant Bogs of Massachusetts

We conducted the first systematic inventory of ant species richness in pitcher-plant bogs of Massachusetts. Twenty-six species were collected in 18 bogs during 1999 and 2000. We collected the bog-specialist Myrmica lobifrons for the first time in Massachusetts and found that it occurred in bogs from the Berkshire Mountains to Nantucket. Ant species composition in bogs displayed a nested subsets pattern, in which the species composition of a bog with few species was generally a subset of the species composition of bogs with more species. This pattern appears to result from different colonization histories of the different bogs. We tested whether ant species richness differed among bog types, ecological subregions, or geographic regions of the state (mainland, Cape Cod, Islands), and whether ant species richness was correlated with variables measured at each bog including: latitude, longitude, elevation, bog mat area; vegetation composition and the density of the carnivorous plant Sarracenia purpurea; and nutrient availability. Among Massachusetts bogs, species richness of ants was predicted best by tree species richness within bogs and by the concentration of ammonium in bog pore-water. Ant species richness was highest in bogs of the Connecticut River Valley and the Massachusetts-Rhode Island border. These are also areas identified by the Massachusetts BioMap project as core areas for biodiversity in the state.