- Strojny, Carol
University of Maine Graduate School
Amphibians that inhabit upland forests are in constant contact with the forest floor, relying on moist conditions for respiration. Timber harvesting can have a negative effect on amphibian populations by altering forest floor microhabitats. We tested the hypothosis that creating small -scale canopy gaps modeled after natural disturbance patterns may retain adequate habitat structure for amphibians, thus facilitating the maitenance of amphibian diversity and abundance in managed forests. From spring-fall 2002 and 2003, we used pitfalls with drift fences to sample 2930 and 9060 amphibians, respectively, in closed-canopy forest plots located in the Penobscot Experimental Forest of central Maine. Location within large harvest gaps (north vs. south aspect, gap center vs. edge) did not influence capture rates for Ambystoma maculatum, Notophthalmus viridescens, plethodon cinerus, Rana catesbeiana, or Ranasylvatica, but higher capture rates at gap edges than gap centers were detected for Rana clamitans. Responses among gap types (large harvest, small harvest, and natural) varied by amphibian species and age-class. Metamorphs (young of the year) had relatively lower capture rates in large harvest gaps for A. maculatum, R. catesbeiana, R. clamitans, R. sylvatica. In some cases (R. clamitans juveniles, R sylvatica juvenile-adults and metamorphs), capture rates in small harvest gaps were similar to natural gaps.