Freshwater Systems

In our area of interest, freshwater systems include the upper waters of coastal rivers or estuaries, tidal freshwater marshes, hardwood swamps, pocosins, Carolina bays and those lands which are closely interconnected with these water bodies. Tidal freshwater marshes are those wetlands that are close enough to the coast to experience tidal influence, but have much lower salinity, and consequently can support a much more diverse array of plant and animal species (Mitsch & Gosselink, 2000). Hardwood swamps are a kind of freshwater wetland under a very slight tidal influence that are forested with large hardwood tree species, in North Carolina this includes Sweet Gum, Bald Cypress and other water loving tree species, and generally border riparian, or river, systems. Pocosins are freshwater upland bog systems unique to the coastal plain of the southeastern United States, and are rainfall dependent systems that evolve over time as peat accumulates. The word pocosin is and Algonquin term meaning “swamp on a hill”, and in NC refers to a broad spectrum of wetlands on the coast, including all shrub and forested bogs ( Richardson, 2003). Carolina bays are unusual elliptical shaped hollows in the sedimentary soils only found in North and South Carolina and small areas in Georgia (Richardson & Gibbons, 1993). These depressions, formed by some unknown force, receive freshwater from precipitation and groundwater recharge, forming isolated freshwater wetlands that dapple the coastal landscape.

Freshwater Wetland Systems in North Carolina

Overall, freshwater systems receive less legal protection than do saltwater systems, and being subject to similar pressures of global change, are more susceptible to degradation and destruction (Mitsch & Gosselink, 2000). Rivers in NC are charged with the unpleasant job of transporting much of the states’ pollution into the ocean, a large amount of which is caused by hog farms and their associated practices. Pollution of rivers in NC has caused the eutrophication of both fresh and salt water systems, causing harmful algael blooms and oxygen depleted waters in important nursery areas. Agriculture plays a dual role in impacts, contributing to pollution in addition to encouraging draining much of the freshwater wetlands to utilize the productive, nutrient rich soils and peat underneath the water. As coastal populations in NC rapidly increase, development encroaches onto the shoreline of rivers, dramatically increasing erosion as well as hugely increasing the pressure to drain these unprotected isolated freshwater areas.

Bald Cypress Swamp

In addition to the direct human impacts of development, agriculture and pollution, NC’s freshwater systems are also at risk from and indirect effect of anthropogenic activities; climate change. Although the response of all the wetlands is uncertain, it is generally believed that as the climate warms and the sea level rises, much of the freshwater wetlands in NC will be reduced greatly in size, as it is unlikely that peat will accumulate fast enough to keep pace (Moorhead & Brinson, 1995). The wetlands that do not disappear under the water will likely change in distribution and vegetative coverage, potentially extirpating many of the species that previously called these areas home.

Major Forest Types in North Carolina