Chapter 4 Habitats
4.3.7 Freshwater Tidal Wetlands 4.3.7.1 Ecosystem Description
Freshwater tidal wetlands occur in sites where flooding occurs in response to lunar or wind tides, but where the water has less than the 0.5 parts per thousand (ppt) salt content used to define freshwater. Tidal freshwaters occur in rivers, where freshwater flow keeps out saltwater, and along the large sounds where distance from seawater inlets keeps the water fresh. Components of this habitat include tidal cypress-gum swamps and tidal freshwater marshes: Tidal cypress-gum swamps occupy vast areas at the mouths of large rivers and occur at the mouths of smaller creeks and occasionally along the sound shoreline. They are dominated by Swamp Black Gum, Water Tupelo, and Bald Cypress. Understory tree, shrub, and herb layers are generally sparse and low in diversity. Tidal freshwater marshes occur in the lowermost parts of some tidal rivers and creeks and, more commonly, in large flats along the shorelines of freshwater sounds. The vegetation is generally strongly zoned and often very diverse in at least some zones. Two distinct variants are recognized, one with very slightly salty (oligohaline) water, the other completely fresh. 4.3.7.2 Location of Habitat These habitats occur along rivers or coastal sounds in areas where flooding is influenced by lunar or wind tides. Fresh water input may heavily influence the salt content. Tidal cypress-gum swamps are extensive along shorelines and along drowned river valleys (e.g . Cape Fear, Neuse, and Chowan rivers). The most extensive examples can be found around Albemarle Sound areas, Alligator River, and at the mouths of the Cape Fear, Neuse, Tar, and Roanoke rivers. Tidal freshwater marshes are common around the margins of Currituck Sound, and occur in smaller areas, such as in the Cape Fear River just west of Wilmington. 4.3.7.3 Problems Affecting Habitats Chapter 5 Threats provides more information about 11 categories of threats most likely to impact North Carolina’s wildlife and natural communities. The list of threats is based on definitions and classifications published by Salafsky et al. (2008, 2024) . The following information focuses on current and anticipated threats for this habitat. Erosion . Erosion control measures may help protect these communities, but measures that alter the shoreline, whether sea walls, “soft” structures, or planting off-site species, are potentially destructive to these communities. Shoreline armoring and hardening to protect infrastructure will prevent ecosystems such as tidal marshes from migrating inland (DeWan et al. 2010) . As development continues inland, water demands in the Piedmont will affect freshwater flows from the major rivers that feed this system through water removals.
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2025 NC Wildlife Action Plan
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