Chapter 4 Habitats
4.3.8 Freshwater Herbaceous Marsh 4.3.8.1 Ecosystem Description
Freshwater herbaceous marsh communities are non-tidal or supratidal (above the spring high tide line) wetland systems dominated by a variety of grasses, sedges, rushes, cattails, cane, and forbs without woody shrubs or trees. They can be classified as peatland canebrakes, Beaver marshes, impoundments and herbaceous marshes in the supratidal-zone that only receive tidal flooding during storm surge events. They occur along streams in poorly drained depressions and in the shallow water along the boundaries of lakes, ponds, and rivers and can be flooded for extended periods during the growing season. In the Coastal Plain, they can also be delineated as supratidal high marsh located in slightly higher elevations transitional between brackish marsh and wetland forest or non-wetland upland communities. The examples of supratidal herbaceous marshes on the upland side near brackish marsh can be dominated by sawgrass ( Cladium spp. ) . Freshwater marshes are known by many names, including emergent wetlands, wet meadows, fens, and sloughs (FGDC 2013) . Water levels in these systems can fluctuate from moist soil to a couple of inches depending on landscape location, hydrologic sources, and seasonal precipitation (USEPA 2024) . Different SGCN can tolerate different water levels. For example, Black Rails require less than one inch of water during the breeding season, while other SGCN can tolerate deeper water depths. As with other wetlands, they mitigate flood damage and filter excess nutrients from surface runoff. They can have highly organic, mineral rich soils of sand, silt, and clay that sustain a vast array of plant communities that in turn provide considerable habitat value and support a wide variety of wildlife. For example, herbaceous communities provide excellent habitat for songbirds, waterbirds, and waterfowl such as Red-winged Blackbirds, Black Rails, American Bitterns, Black Ducks, and Great Blue Herons as well as small mammals such as American Otters and Muskrats (USEPA 2024) . The freshwater marsh natural community is a new wetland description added to the SWAP during the 2025 revision process. 4.3.8.2 Location of Habitat These habitats occur in small pockets throughout the state. Today they are found mostly in the Coastal Plain, are mainly rain or freshwater fed and are located beyond normal tidal influences adjacent to and at slightly higher elevations than brackish and salt marshes. They occur in smaller occurrences statewide, primarily along slow-moving rivers and streams, in Beaver dam marshes, old oxbows and overflow channels, in ditched areas, impoundments, around the edges of ponds and lakes, or in relatively flat areas or shallow depressions that intercept the groundwater table ( NCDWR 2024a, NatureServe 2024) . These wetlands can be identified through GIS
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2025 NC Wildlife Action Plan
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