Amphibian Biomass Export from Geographically Isolated Wetlands: Temporal Variability, Species Composition, and Potential Implications for Terrestrial Ecosystems
Julia E. Earl,
Sean M. Blomquist,
Elizabeth B. Harper,
Daniel J. Hocking,
Malcolm L. Hunter,
Jarrett R. Johnson,
Michael S. Osbourn,
David A. Patrick,
Viorel D. Popescu,
Tracy A. G. Rittenhouse,
Betsie B. Rothermel
Affiliations
Julia E. Earl
School of Biological Sciences, Louisiana Tech University, Ruston, LA 71272, USA
Sean M. Blomquist
Branch of SSA Science Support, US Fish and Wildlife Service, MS: ES, 5725 Leesburg Pike, Falls Church, VA 22041, USA
Elizabeth B. Harper
Division of Science, Health and Education, New England College, Henniker, NH 03242, USA
Daniel J. Hocking
Greater Atlantic Regional Fisheries Office, NOAA National Marine Fisheries Service, 55 Great Republic Drive, Gloucester, MA 01930, USA
Malcolm L. Hunter
Department of Wildlife, Fisheries, and Conservation Biology, University of Maine, Orono, ME 04469, USA
Jarrett R. Johnson
Department of Biology, Western Kentucky University, Bowling Green, KY 42103, USA
Michael S. Osbourn
Wildlife Biology Program, Lees-McRae College, Banner Elk, NC 28604, USA
David A. Patrick
Chief Conservation Office, The Nature Conservancy, 4245 Fairfax Dr. #100, Arlington, VA 22203, USA
Viorel D. Popescu
Department of Biological Sciences, Ohio University, 107 Irvine Hall, Athens, OH 45701, USA
Tracy A. G. Rittenhouse
Department of Natural Resources and the Environment, University of Connecticut, 1376 Storrs Rd, Storrs, CT 06269, USA
Recently metamorphosed amphibians transport substantial biomass and nutrients from wetlands to terrestrial ecosystems. Previous estimates (except 1) were limited to either a subset of the community or a single year. Our goal was to examine temporal variability in biomass export of all amphibians within breeding ponds and the composition of that export. We completely encircled ponds with drift fences to capture, count, and weigh emerging recently metamorphosed individuals in Maine (four wetlands, six years) and Missouri (eight wetlands, 2–4 years). We estimated total amphibian biomass export, export scaled by pond surface area, species diversity, and percentage of biomass from anurans. Biomass export and export composition varied greatly among ponds and years. Our estimates were of similar magnitude to previous studies. Amphibian biomass export was higher when species diversity was low and the proportion of anurans was higher. Biomass estimates tended to be highest for juvenile cohorts dominated by a single ranid species: green frogs (Missouri) or wood frogs (Maine). Ranid frogs made up a substantial proportion of amphibian biomass export, suggesting that terrestrial impacts will likely occur in the leaf litter of forests. Future studies should examine the impacts of ranid juveniles on terrestrial ecosystem dynamics.
