Ants play an instrumental role in the forests of New England by aerating the soil and promoting habitat biodiversity. These essential services are not carried out by one genus alone; it takes a collection of colonies of various species functioning together to sustain a healthy forest. In order to expand our understanding of the variety and distribution of ant species and their relative contributions to the local ecosystem, the population density, biodiversity, and habitat preferences of ant species in the secondary growth deciduous forest of Harvard Forest in Central Massachusetts were examined. Ant colonies were surveyed in five plots of thirty-six square meters each using an intensive forest floor disturbance method and identified all colonies according to species and habitat type. Colonies were mapped to illustrate their relation to one another within the area of study.
The mapping and analysis of these plots showed the presence of four genera and six main species, among which their prevalence varied greatly. Lasius nearticus was found most commonly (representing approximately 60% of the total sample, n=149 colonies) with a population density of 0.51 colonies of per square meter. Apheanagaster picea was identified at a density of 0.23/m2 (27% of the total). Lasius umbratus and Myrmica punctiventris were both present at a density of 0.4/m2 (5% each of the total), with very few occurrences of Lasius alienus at 0.02/m2 and Formica neogagates at 0.01/m2 (2% and 1% respectively). Lasius nearticus was found almost exclusively in surface soil (87% of the specie specific sample), while all other species of substantial sample size were found in a more diverse range of habitat with minor preferences. These findings suggest that there may be a combination of factors specific to individual specie preferences, including habitat type and availability, which shape the population density and biodiversity of ants present on the forest floor.