SREL Reprint #1852

 Changes in amphibian biodiversity associated with 25 years of pine forest regeneration: implications for biodiversity management

Bruce W. Grant1,2, Kent L. Brown3, Gary W. Ferguson3, and J. Whitfield Gibbons1

1University of Georgia, Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802
2Department of Biology, Widener University, Chester, PA 19013
3Department of Biology, Texas Christian University, Fort Worth, Texas 76129

Abstract: Global biodiversity decline, especially for amphibians, is presently of international concern. Data are critically lacking on the effects of human impacts on biodiversity, especially regarding silvicultural management of public and private land. In response to this need, we present data on variation in amphibian biodiversity in replicated stands of one-, three-, eight- and twenty-six-year old loblolly pine trees managed by the USFS on the Savannah River Site in South Carolina. According to censusing using terrestrial drift fences and pitfall traps, from March to November, 1979, intermediate-aged stages of regeneration had higher amphibian species diversity than did either the youngest or oldest stand. Neither the total number of amphibians nor an estimate of total amphibian biomass were correlated with regeneration age.
During the process of even-aged pine forest regeneration, forest structural diversity is initially low after clearcutting and replanting, followed by a decade or more of dense foliage and high habitat structural diversity. As the pine monoculture matures, periodic burning and thinning clears understory vegetation and reduces structural diversity at ground level where most amphibians occur. Thus, we suggest that in our study plots amphibian biodiversity might have been greater in more structurally diverse stages of regeneration, especially near ground level, although the precise mechanisms remain unknown.
Studies are needed to elucidate determinants of diversity within managed landscapes. In particular, field studies of the mechanisms underlying amphibian population dynamics in response to forest structural diversity would enable land managers to refine existing and develop new management techniques that minimize biodiversity loss while maximizing economic yield.

Keywords: biodiversity, amphibian decline, forest regeneration

SREL Reprint #1852

Grant, B.W., K.L. Brown, G.W. Ferguson, and J.W. Gibbons. 1994. Changes in amphibian biodiversity associated with 25 years of pine forest regeneration: implications for biodiversity management. pp. 355-367 In: S. K. Majumdar, F. J. Brenner, J. E. Lovich, J. F. Schalles, and E. W. Miller. (Eds.). Biological Diversity: Problems and Challenges. The Pennsylvania Academy of Science. 

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).