SREL Reprint #2359

An introduction to freshwater wetlands in North America and their invertebrates

Rebecca R. Sharitz and Darold P. Batzer

Introduction: North America has an abundance and diversity of wetlands. The ecological values of these systems, their complexity, the ecosystem services they provide, and their connection with the surrounding landscape are still not well understood. The wetlands that now occur in North America may represent only a fraction of those existing 200 or more years ago. Although estimates of the extent of wetlands in the United States vary widely, most studies indicate a rapid rate of loss, at least prior to the mid-1970s. The most accurate estimate of present wetland area in the conterminous United States is 42 million hectares (Dahl and Johnson 1991), of which 80 percent are inland wetlands and 20 percent are coastal (Frayer et al. 1983). In Alaska there are about 69 million hectares (Dahl 1990) and in Canada about 127 million hectares of wetland area (Zoltai 1989). Historically, policies of the United States government were intended to encourage or subsidize the conversion of wetlands to filled or drained lands that could be used for agriculture or other purposes. Only recently have the unique properties and multiple values of wetlands become better appreciated, especially ecosystem services such as improving water quality, reducing effects of floodwaters, and providing habitat for many groups of animals and plants (Daily 1997). Wetland protection is now a common objective of laws, regulations, and management plans.

SREL Reprint #2359

Sharitz, R.S. and D.P. Batzer. 1999. An introduction to freshwater wetlands in North America and their invertebrates. pp. 1-22 In: Batzer, D.P., R.B. Rader, and S.A. Wissinger (Eds.). Invertebrates in Freshwater Wetlands of North America: Ecology and Management. John Wiley & Sons, Inc.

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