SREL Reprint #2438

Relationships among isolated wetland size, hydroperiod, and amphibian species richness: implications for wetland regulations

Joel W. Snodgrass1,2, Mark J. Komoroski2, A. Lawrence Bryan Jr.2, and Joanna Burger1

1Division of Life Sciences, and Consortium for Risk Evaluation with Stakeholder Participation,
Environmental and Occupational Health Sciences Institute, Rutgers University,
Piscataway, NJ 08854, USA
2Savannah River Ecology Laboratory, University of Georgia, Drawer E, Aiken, SC 29802, USA

Abstract: Wetland development within the United States is regulated primarily by size. Decisions concerning wetland destruction or conservation are therefore based in part on three inherent assumptions: (1) small wetlands contain water for short portions of the year; (2) small wetlands support few species; and (3) species found in smaller wetlands are also found in larger wetlands. We tested these assumptions using data on wetland size, relative hydroperiod (drying scores), and relative species richness of amphibians in depression wetlands of the southeastern United States. We found a significant (p=0.03) but weak (r2=0.05) relationship between hydroperiod and wetland size and no relationship (p=0.48) between amphibian species richness and wetland size. Furthermore, synthetic models of lentic communities predict that short-hydroperiod wetlands support a unique group of species. Empirical investigations support this prediction. Our results indicate that hydroperiod length should be included as a primary criterion in wetlands regulations. We advocate a landscape approach to wetlands regulation, focused in part on conserving a diversity of wetlands that represent the entire hydroperiod gradient.

SREL Reprint #2438

Snodgrass, J. W., M. J. Komoroski, A. L. Bryan, Jr., and J. Burger. 2000. Relationships among isolated wetland size, hydroperiod, and amphibian species richness: implications for wetland regulations. Conservation Biology 14:414-419.

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