Effects of group selection silviculture in bottomland hardwoods on the spatial activity patterns of bats

• Published in: Forest ecology and management 2002-06, Vol.162 (2), p.209-218
• Main Authors: Menzel, Michael A., Carter, Timothy C., Menzel, Jennifer M., Mark Ford, W., Chapman, Brian R.
• Format: Article
• Language: English
• Subjects: Anabat; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Biological and medical sciences; Bottomland hardwoods; Demecology; Foraging; Forestry; Fundamental and applied biological sciences. Psychology; General forest ecology; Generalities. Production, biomass. Quality of wood and forest products. General forest ecology; Group selection silviculture; Habitat use; Mammalia; Vertebrata
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/S0378-1127(01)00516-3

The effects of forest management practices on the spatial activity patterns of bats are poorly understood. We determined the effect of group selection timber harvests on the spatial activity patterns of bats below the forest canopy at the Savannah River Site, Aiken, SC, using the Anabat system. We monitored the effect of group selection timber harvests on feeding and foraging activity of bats at three spatial scales: among habitats within a landscape, among harvested and unharvested areas in the stand where patches were harvested, and within an individual gap. Habitats examined included Carolina bays, unharvested bottomland hardwoods, bottomland hardwoods in which a group selection harvest occurred, and upland stands containing a hardwood/pine mix. Within the harvested stand, we compared the level of foraging and feeding activity among large patch cuts (gaps), small gaps, skidder trails, and forested areas. Within the large gaps, we compared activity among the center of the gap, the edge of the gap, and the forest surrounding the gap. Levels of bat activity differed among stands. More activity occurred in the bottomland stand in which patches had been harvested and around Carolina bays than in unharvested stands of bottomland hardwoods and upland hardwoods and pines. Levels of bat activity also differed among harvested and unharvested areas within the stand and among different positions within gaps and the surrounding forest. Activity was concentrated in forest gaps and along skidder trails. Within gaps, activity was concentrated along the edge between the gap and forest. Spatial activity patterns also depended on the species of bat. These results suggest that the inclusion of gaps in bottomland hardwoods increases the total level of foraging and feeding activity of bats below the canopy. They also suggest differences in the size and shape of the harvest affect the total amount of bat activity recorded in the gap and that these effects may be species specific.