Wetlands 101

What is a wetland?

Basin Wetland
Basin Wetland (Photo provided by Kristie Gianopulos)

A wetland is any place where there is shallow water or very soggy soil. The soil could be either permanently or seasonally saturated or inudated (flooded) with water.  Because of the presence of water, the wetland will develop “hydric” or wet soils and  provide habitat for plants that thrive in a wetter environment.  Wetlands are the link between dry land and bodies of water, making them unique ecosystems that support many important processes that do not occur elsewhere.

Why should we care about wetlands? 

Wetlands are often described as the “kidneys of the landscape” because of the important natural benefits they provide:

Wetlands store water and provide important habitat. (Photo provide by Rick Trone)
  1. Wetlands act like a giant sponge, holding water for a variety of services across the landscape.
  2. Wetland protect our communities from flooding.
  3. Wetlands protect lake and estuarine shorelines from erosion.
  4. Wetlands provide critical habitat for endangered species, and a wide variety of other wildlife.
  5. Wetlands clean and filter water for drinking, swimming, boating, and fishing.
  6. Wetlands help regulate stream flow and recharge our groundwater.
  7. Wetlands provide food for fish and shellfish (like oysters) that we eat.
  8. Wetlands provide places for outdoor education, recreation, and relaxation.

Without wetlands, many animals and plants would become extinct, and flooding and pollution would be much worse.

Lakes are wet, are they wetlands too?

No – they are too wet. Remember wetland plants? Lakes are mostly too deep for wetland plants to take hold. But, wetlands can develop along the edges of lakes.

Wetlands are found between lakes and adjacent uplands and protect the shoreline from erosion. (Photo from Seminole Audubon).

Where do wetlands develop?

Wetlands can form anywhere that water may sit long enough for a saturated soil to develop. Wetlands are typically found by rivers, streams, lakes, and the ocean, but they can also develop in upland depressions or at the base of a hillslope.

How do wetlands get wet? 

Rainfall, groundwater, and floodwaters provide water to wetlands (photo by Rick Trone)

Rain and snow melt feed water to wetlands. Wetlands also receive water from beneath the ground, from surface runoff, and floodwaters from rivers, streams, or ocean tides.

What are the types of wetlands and how are they define? 

Wetland scientists have developed “classification systems” to organize wetlands with similar characteristics. Two of the most common systems are known as “Cowardin” and “Hydrogeomorphic” (HGM) classification systems and can be used anywhere in the United Stations. The “North Carolina Wetland Assessment Method” (NCWAM) was developed specifically for North Carolina and is useable in South Carolina and Virginia.

What wetland characteristics are used by the NCWAM classification system?

Hydrology – Does the water source seep from underground, or does it flow overland from rivers, streams, or ocean tides? Is the wetland flooded for most of the year or is the soil saturated for a few months?

Landscape position – Is the wetland near a lake, river, or stream or is it higher up in the watershed and surrounded by upland?

Soil type – Does the wetland have mineral soil like sand or silt, or is the soil organic like the muck or peat found in a bog?

Vegetation structure – Is the wetland forested, shrub covered, or herbaceous?

Dominant vegetation species – What types of trees, shrubs, or herbaceous plants are most prevalent in the wetland community?


Click here to learn more about wetland communities in the Carolinas, 


References

Brinson. M.M. 1993. A hydrogeomorphic classification for wetlands, Technical Report WRP-DE-4, U.S. Army Corps of Engineers Engineer Waterways Experiment Station, Vicksburg, MS.

Cowardin, L. M., V. Carter, F. C. Golet, and E. T. LaRoe. 1979. Classification of Wetlands and Deep Water Habitats of the United States.

Wisconsin Wetlands Association website: wisconsinwetlands.org, 214 N. Hamilton St. #201 Madison, WI 53703.

Mitsch, W.J. and J.G. Gosselink. Wetlands, 2nd Edition. Van Nostrand Reinhold Publishing. 1995. National Wildlife Federation. 2016.

Nelson, John B. The Natural Communities of South Carolina. 1986. South Carolina Wildlife & Marine Resources Department.

North Carolina Wetland Functional Assessment Team. 2010. North Carolina Wetland Assessment Method (NCWAM) Version 4.1.

Schafale, Michael P. Guide to the Natural Communities of N. C., Fourth Approximation. 2012. North Carolina Natural Heritage Program, NC Department of Environment and Natural Resources.

US Environmental Protection Agency. 2016. National Wetland Condition Assessment 2011: A Collaborative Survey of the Nation’s Wetlands.