Impacts of Forestry on Ant Species Richness and Composition in Warm-Temperature Forests of Japan

Ants, which are exceedingly important in forest ecosystems, are very sensitive to various types of forest disturbance. In this study, the long-term impacts of forestry on the species richness and species composition of ant assemblages were investigated in a warm-temperature forestry area in southwestern Japan. Ant assemblages from old-growth native forests, second-growth native forests, and conifer plantations were compared. Ants were samples during 15-min time units in five old-growth native forests, four second-growth native forests, and three conifer plantations, and the ants were identified to specie. Ant species composition was analyzed by correspondence analysis. The mean number of ant species was not significantly different between the three forest types, and species richness was not correlated with altitude, the number of woody plant species, or the maximum diameter at breast height of conifers or broad-leaved trees. However, the number of ant species at each site was significantly different between old-growth and converted forests for each group of ants. In second-growth native forests and conifer plantations, some woodland specialists had disappeared, but open-habitat specialists had appeared, and more species of habitat generalists were found than in old-growth forests.