Response of reptile and amphibian communities to canopy gaps created by wind disturbance in the Southern Appalachians
Reptile and amphibian communities were sampled in intact gaps created by wind disturbance, salvage-logged gaps, and closed canopy mature forest (controls). Sampling was conducted during June–October in 1997 and 1998 using drift fences with pitfall and funnel traps. Basal area of live trees, shade, leaf litter coverage, and litter depth was highest in controls and lowest in salvaged gaps. Percent cover, length, and diameter of coarse woody debris (CWD) were significantly greater in intact gaps than in salvaged gaps or controls. Coarse woody debris was more decayed and had less bark in controls than gaps. The relative abundance of salamanders and American toads, and species richness and diversity of amphibians did not differ among treatments. In contrast, relative abundance of two lizard species and (marginally) snakes, and species richness and diversity of reptiles was higher in both gap treatments than in controls. Results suggest that higher light in gaps positively influenced reptile abundance, but CWD at the tested levels was not an important determinant of habitat quality. The presence of a partial canopy and other forest features in both gap treatments may have adequately retained the microclimatic conditions required by moisture-sensitive amphibians. Xeric study sites and an associated assemblage of species that are pre-adapted to relatively warm, dry conditions also might partially explain the absence of any significant response by amphibians. In the closed canopy forests of the Southern Appalachians, I suggest that salamanders were historically dominant, whereas many reptile species occurred at low densities and depended upon infrequent natural disturbance to create ephemeral patches of suitable habitat. Further study is required to determine what parameters of disturbance influence reptile and amphibian communities, and how these effects might differ along a moisture gradient and among species.