Arboreal ant community of a pine forest in northern Florida

The arboreal ant fauna of the longleaf and slash pine forests of the Apalac hicola National Forest in northern Florida was studied using baits placed o n trunks 1 m above ground level. Crematogaster ashmeadi Mayr was by far the most abundant ant attracted to the baits, occurring on approximate to 50% of all the trees. In addition to C. ashmeadi, another 10 species of ants, b oth ground-nesting and arboreal-nesting, were commonly captured. There was a strong relationship between the identity and abundance of species of ants on Dines and the mean tree diameter, indicating that the ant fauna changed as trees grew. In young, recently regenerated stands, baits attracted most ly ground-nesting species of ants. Newly mated C. ashmeadi queens colonize the dead branches of pine saplings. As tree size increased, tree occupancy by C. ashmeadi rose to a maximum of 60% in middle-sized trees and fell to 5 0% in the largest trees. Parallel to these changes, the proportion of trees occupied by ground-nesting ants fell fi om 33% in the smallest Dines to ap proximate to 15% in the largest, whereas those occupied by arboreal ants ot her than C. ashmeadi rose from 2 to 25%. The data suggested that C. ashmead i is a dominant ant species with which other species do not easily coexist. Coexistence of arboreal ants increased with tree size such that the propor tion of trees with >1 species increased steadily from approximate to 4% in the smallest pines to approximate to 19% in the largest. The total number o f species was about the same in small, medium, and large trees, but the ide ntity of these species changed. As in other ant communities, the assembly o f the arboreal ant community in this pine for est is probably an example of the nested-subset phenomenon. That is, the occurrence of species is determ ined by their ability to coexist with the dominant, aggressive, large-colon ied species, in this case, C, ashmeadi.