CHANGES IN AMPHIBIAN BIODIVERSITY
ASSOCIATED WITH 25 YEARS OF PINE FOREST
Implications for Biodiversity Management
BRUCE W. GRANT1,2, KENT L. BROWN3, GARY W. FERGUSON3, and J. WHITFIELD
1Univesity of Georgia, Savannah River Ecology Laboratory, Drawer E, Aiken, SC
2Department of Biology, Widener University, Chester, PA 19013
3Department of Biology, Texas Christian University, Fort Worth, Tom 76129
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
lobloily 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 need 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
manage" to refine existing and develop new management techniques that
minimize biodiversity loss while maximizing economic yield.
Key words: 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. In Biological Diversity: Problems and
Challenges, edited by S.K. Majumdar, F.J. Brenner, J.E. Lovich, J.F. Schalles,
and E.W. Miller. p. 355-367. The Pennsylvania Academy of Science.
To request a reprint