United States Office of Water EPA 843-F-01-002b Environmental Protection Office of Wetlands, September 2001 Agency Oceans and Watersheds (4502T)

Do you think all wetlands are the same? Think again. Each wetland differs due to variations in soils, landscape, climate, water regime and chemistry, vegetation, and human disturbance. Below are brief descriptions of the major types of wetlands found in the United States

eddish egret R organized into four general categories: marshes, swamps, bogs, and fens.

ARSHES are periodically saturated, M flooded, or ponded with water and charac- terized by herbaceous (non-woody) vegetation adapted to wet soil conditions. Marshes are further characterized as tidal marshes and non-tidal marshes. ! Freshwater marshes are characterized by Tidal (coastal) marshes occur along periodic or permanent shallow water, little coastlines and are influenced by tides or no peat deposition, and mineral soils. and often by freshwater from runoff, They typically derive most of their water rivers, or ground water. Salt marshes from surface waters, including floodwater are the most prevalent types of tidal and runoff, but do receive ground water

The Vernal Pool Association Pool The Vernal marshes and are characterized by salt- inputs. Many vernal pools fill with water in tolerant plants such as smooth cord- fall or spring. grass, saltgrass, and glasswort. Salt ! Wet meadows commonly occur in poorly marshes have one of the highest rates of drained areas such as shallow lake basins, primary productivity associated with low-lying depressions, and the land wetland ecosystems because of the between shallow marshes and upland areas. inflow of nutrients and organics Precipitation serves as their primary water from surface and/or tidal water. supply, so they are often dry in the summer. Tidal freshwater marshes are located ! Wet prairies are similar to wet meadows upstream of estuaries. Tides influence but remain saturated longer. Wet prairies water levels but the water is fresh. may receive water from intermittent The lack of salt stress allows a streams as well as ground water and

Leigh Dunkelberger greater diversity of plants to thrive. precipitation. Freshwater marshes, like this one in Cattail, wild rice, pickerelweed, Sequoia National Park, are dependent ! Prairie potholes develop when snowmelt on rainfall, runoff, and seasonal and arrowhead are common and flooding for their water supplies. help support a large and diverse and rain fill the pockmarks left on the range of bird and fish species, landscape by glaciers. Ground water input among other wildlife. is also important. Nontidal (inland) marshes are ! Playas are small basins that collect rainfall dominated by herbaceous plants and runoff from the surrounding land. and frequently occur in poorly These low-lying areas are found in the drained depressions, floodplains, Southern High Plains of the United States. and shallow water areas along the ! Vernal pools have either bedrock or a hard edges of lakes and rivers. Major clay layer in the soil that helps keep water Dave Davis regions of the United States that in the pool. They are covered by shallow Farmland surrounds these prairie support inland marshes include the potholes in Nebraska. water for variable periods from winter to Great Lakes coastal marshes, the spring, but may be completely dry for most prairie pothole region, and the of the summer and fall. Florida Everglades. WAMPS are fed primarily by surface water These tropical and subtropical systems have a Sinputs and are dominated by trees and North American range that extends from the south- shrubs. Swamps occur in either freshwater or ern tip of Florida along the Gulf Coast to Texas. saltwater floodplains. They are characterized by very wet soils during the growing season and OGS are freshwater wetlands characterized standing water during certain times of the year. Bby spongy peat deposits, a growth of ever- Well-known swamps include Georgia’s Oke- green trees and shrubs, and a floor covered by a

U.S. Army Corps of Engineers fenokee Swamp and Virginia’s Great Dismal thick carpet of sphagnum moss. These systems, Trees found in Swamp. Swamps are classified as forested, whose only water source is rainwater, are swamps are some- shrub, or mangrove. usually found in glaciated areas of the northern times buttressed at United States. One type of bog, called a the base, which Forested swamps are found in broad helps anchor them in pocosin, is found only in the the saturated soils. floodplains of the northeast, southeast, and Southeastern Coastal Plain. south-central United States and receive floodwater from nearby ENS are ground rivers and streams. Common Fwater-fed peat- deciduous trees found in these areas forming wetlands include bald cypress, water tupelo, covered by grasses, swamp white oak, and red maple. sedges, reeds, and Shrub swamps are similar to wildflowers. Willow forested swamps except that and birch are also common. Fens, like Dave Davis shrubby species like buttonbush and Bog ecosystems Forested swamps serve a swamp rose dominate. bogs, tend to occur in support critical role in the water- glaciated areas of the cranberries, shed by reducing the risk Mangrove swamps are coastal wetlands char- northern United blueberries, and and severity of flooding carnivorous to downstream areas. acterized by salt-tolerant trees, shrubs, and other States. plants like the plants growing in brackish to saline tidal waters. pitcher plant.

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For more information, visit www.epa.gov/owow/wetlands.

On the Internet EPA’s Wetland Home Page contains information and pictures on several types of wetlands ...... www.epa.gov/owow/wetlands/types Types of Wetlands and Their Roles in the Watershed, part of North Carolina State University’s WATERSHEDSS ...... h2osparc.wq.ncsu.edu/info/wetlands/types3.html Wetlands of the United States from the USGS Northern Prairie Wildlife Research Center ...... www.npwrc.usgs.gov/resource/1998/uswetlan/types.htm Prairie Potholes ...... www.greatplains.org/resource/1999/ppjv/ppjv.htm In Print Wetlands. 3rd Edition. W.J. Mitsch, and J.G. Gosselink. 2000. John Wiley & Sons, Inc. New York, NY. In Search of Swampland: A Wetland Sourcebook and Field Guide. R.W. Tiner, 1998. Rutgers University Press, Piscataway, NJ. Adopting a Wetland—A Northwest Guide. S. Yates. 1989.