Using ground foraging ant (Hymenoptera: Formicidae) functional groups as bioindicators of forest health in Northern Arizona ponderosa pine forests.

摘要

Reintroduction of fire and thinning have been suggested as the main practices to regain forest health in ponderosa pine forests of northern Arizona. Recent silvicultural programs and the occurrence of catastrophic wildfires have created a range of disturbance severities and a mosaic of forest conditions. Sixteen stands were randomly selected to create a completely randomized experimental design with four treatments, (1) unmanaged, (2) thinned, (3) thinned and burned, and (4) wildfire, with four replicates of each treatment. We assessed changes occurring in ground foraging ant functional groups at the stand scale as related to these treatments. A pitfall trapping scheme was implemented during the summer months of 2002 and 2003. A total of 18 009 specimens were collected representing 20 species from 10 genera. We found that traditional biodiversity measures, such as species richness, diversity, and dominance were a less satisfactory measure of treatment impact on ants than functional group analysis, which allowed us to consider the ecosystem role of each species. We found that different functional groups were dominant under different levels of disturbance severity and suppressed or excluded other functional groups that were less suited to the disturbance intensity. Maintaining a diversity of habitat types is suggested for supporting ecologically diverse ant functional groups and improve forest health..