Impacts of forestry on ant species richness and composition in warm-temperate forests of Japan

To understand the long-term impacts of forestry, i.e., the conversion of old-growth native forests to second-growth native forests or conifer plantations, on ant species richness (i.e., the number of species) and species composition, ant assemblages from five old-growth forests (more than 120 years), four second-growth forests (30-70 years) and three conifer plantations (30-40 years) were compared in the Shimanto River Basin, Shikoku, southwest Japan. The number of ant species collected totaled 39. The number of ant species from the old-growth native forests, second-growth native forests and conifer plantations was 10-20, 15-20 and 11-15, respectively. The overall ant species richness had not been affected by forest conversion. However, correspondence analysis (CA) showed that the ant species composition was markedly different between old-growth forests and converted forests (second-growth forests and conifer plantations). The species richness of woodland specialists was greater in the old-growth forests, and open-habitat specialists and habitat generalists dominated the converted forests. The impacts of forestry on ant assemblages were of a long duration. Ant assemblages of the second-growth forests under regeneration for 40-70 years after logging were still distinct from those of old-growth forests. Careful management of second-growth forests bordering old-growth remnants would be essential to prevent the invasion of open-habitat species of ants into the interior of old-growth forests. (C) 2003 Elsevier B.V. All rights reserved.