A third of all species of birds, 190 species of amphibians, and all of America's wild ducks and geese depend on wetlands for their survival. Wetlands are alive with plants, too. Buttonbush, pitcher plants, wild rice, and water oaks are among the nearly 5,000 species of plants found in our Nation's wetlands.

Wetlands are some of the most productive and dynamic habitats in the world. The physical, chemical, and biological interactions within wetlands include surface and subsurface water storage, nutrient cycling, particulate removal, maintenance of plant and animal communities, water filtration or purification, and groundwater recharge. Wetlands reduce damage from flooding, provide water quality improvement, and fish and wildlife habitat enhancement.

It is important to maintain and restore wetland functions and values because wetlands contribute to the overall health of the environment.

Surface water storage

Subsurface water storage

Wetlands are reservoirs for rainwater and runoff. As this water is released into the ground, it recharges water tables and aquifers, and extends the period of stream flows in many parts of the United States.

Nutrient cycling

Wetlands enhance the decomposition of organic matter, incorporating nutrients back into the food chain.

Retention of particles

By filtering out sediments and particles suspended in runoff water, wetlands help prevent lakes, reservoirs, and other resources from being affected by downstream sediment loading. This improves water quality by reducing sedimentation rates.

Values to Society

There are a number of other values society receives from wetlands. Some of these values are providing sites for hunting, fishing, trapping, photography, outdoor classrooms or environmental education, and the enjoyment of open spaces. The ecological diversity and high productivity of wetlands make them one of the most scenic features on any landscape.

Types of Wetlands

Tidal and Freshwater Marshes

Tidal and freshwater marshes are characterized by herbaceous plants and ponded water that varies in depth with the season. Some marshes, such as coastal marine wetlands, may be flooded year-round. Other types, such as prairie potholes, may be completely dry for much of the year. During dry years, some are farmed. Most prairie pothole wetlands were formed in depressions left by retreating glaciers; however, some were created by wind or other geological process. Prairie pothole wetlands furnish much of our waterfowl habitat. They are commonly found in north-central North America.

Swamps and floodplain forests

Swamps and floodplain forests are dominated by trees, shrubs, and other woody plants adapted to flooding, ponds, or saturated soil conditions. They develop along floodplains, ox-bows, and backwater reaches of rivers and streams. Swamps and floodplain forests are particularly prevalent in the   Southeastern United States. They are important for wildlife habitat, floodwater storage, and trapping sediment.

Bogs

Bogs are typically found in formerly glaciated parts of the Northeast and the Appalachian Mountains. They are characterized by a peaty substrate, evergreen trees, shrubs, and sphagnum moss.