Middle Atlantic Coastal forests

• Category: Forest Biomes.
• Geographic Location: North America.
• Summary: The Middle Atlantic coastal forest is among the most diverse landscapes in North America, harboring unique and rare ecosystems that are under increasing pressure from a growing human population.

Stretching from the eastern shore of Delaware and Maryland to Georgia, the Middle Atlantic coastal forest is sandwiched between the Atlantic Ocean to the east and the uplands of the Piedmont region to the west. This region cannot be defined by a single land use type or ecosystem. It is a patchwork of wild lands mixed with various forms of human development. Unique in many ways, this landscape harbors some of the richest ecosystems in North America, in terms of number of species and biological productivity. Forbidding swamps are among its most well-known habitats, although various types of forests and wetlands cover this vast coastal lowland. At the same time, humans have altered this landscape in a variety of ways, fragmenting much of the original habitat into isolated blocks of wilderness. As a result, many of the species and ecosystems characteristic of this region are considered endangered in the twenty-first century.

Water is a defining feature of this biome, fostering a diverse array of habitats dependent on the amount of water and the timing of flows. Slow-moving rivers flowing from the Appalachian highlands create vast bottomland swamps before they reach the Atlantic Ocean. Rivers such as the Roanoke, Cape Fear, James, and Savannah generate expansive floodplains that have mostly avoided human development. Deep swamps are dominated by bald cypress, water tupelo, and Atlantic white cedar trees which flank the riverbanks. Thick mats of Spanish moss blanket many of these trees, creating an image many people associate with the southern United States. Many of these bottomland forests are constantly covered in water, although there is seasonal variability. The flow of water brings with it sediments and organic matter from the upper regions of the watershed, which feeds plant communities. Even areas away from rivers are governed by water, since this region harbors the greatest diversity of wetland communities in North America.

The push and pull of fire and water reveal two of the forces most responsible for shaping the ecology of this region. The Atlantic Ocean provides a temperature buffer across the region, generating a warm, temperate climate. Winters are mild and are followed by wet, warm springs that send a flood of water into coastal areas. Summers are hot and humid, and these conditions can extend into the fall. Fire frequency is at its greatest during late summer and early fall. Species in this region are adapted to the effects of both flooding and fire. Hurricanes are another important force in this coastal region, capable of causing widespread disturbance and dispensing drenching rains.

Wetland Vegetation

Pine trees dominate in drier, sandy areas, whereas hardwood tree species are found in the moister environments. Unique ecosystems include the longleaf pine savannas and pocosin wetlands. Longleaf pine savannas consist of open expanses of grasses sparsely populated by longleaf pine trees. This habitat harbors an incredible array of flora, including several species of carnivorous plants, such as Venus flytraps, sundew, and pitcher plants. These ecosystems would not exist if not for fire, as periodic burning reduces the density of trees and shrubs, and allows grasses and other low-growing plants to thrive. Fire also returns nutrients to the soil. Some plants' seeds will not germinate until they have been exposed to high temperatures. Full-grown longleaf pines are mostly resistant to small fires, allowing them to compose the upper canopy of these savannas.

Pocosin is an Algonquin word for “swamp on a hill,” which reflects the unusual elevated nature of these thick evergreen wetlands. Occurring on damp soils, pocosin habitats develop in poorly drained locations away from rivers in which water is provided from underground seeps. Vegetation in these areas is very thick, usually dominated by pond pine and evergreen shrubs such as gallberry. Again, this ecosystem is dependent on fire. For example, pond pines are serotinous, meaning that their cones will not open and disperse seeds unless they are burned. Given the thick vegetation and dense organic soil, fires in pocosins can burn underground, potentially for long periods.

Wildlife Species

Due to the foreboding nature of this swampy biome, much of the region has escaped human development, allowing it to serve as a sanctuary for robust wildlife populations such as white-tailed deer, coyotes, foxes, bobcats, and black bears. Aquatic areas are patrolled by beavers, muskrats, otters, and invasive nutria, which were introduced to the southeastern United States for the fur trade. Because of its remoteness, this region was selected as a reintroduction site for the critically endangered red wolf, first introduced in 1987. While in 2005–2006, the red wolf population in northeastern North Carolina was 130, it had plummeted to only seven wolves by 2021. To rebuild it, four adult red wolves were released in the area and four pups were being fostered by a female in the wild. In 2024, the US Fish & Wildlife Service data showed there were sixteen confirmed red wolves in the wild, with an estimated seventeen to nineteen wolves present in the wild. Additionally, there were 290 red wolves successfully living in captivity. Future release plans in North Carolina's coastal forest habitat included pairing two wild red wolves of breeding age, or one wild wolf and one captive wold of breeding age before releasing into the wild, with the intention of the red wolf pairs breeding in the wild to further perpetuate the population over time.

Wetlands sustain tremendous levels of bird diversity, and areas such as northeastern North Carolina support large concentrations of migratory geese and swans. Alligators roam many of the waterways, along with an assortment of turtles and frogs. Venomous snakes are common, including copperheads, water moccasins, and rattlesnakes. Warm-water game fish such as largemouth bass, catfish, panfish, and gar are popular species sought by anglers and are plentiful in many of the waterways. Many of the larger rivers are important spawning areas for anadromous marine fish, such as striped bass, American shad, shortnose sturgeon, and Atlantic sturgeon. In the twenty-first century, groups such as the National Oceanic and Atmospheric Administration (NOAA) are working to increase the populations of these migratory species. A variety of strategies such as removing barriers like dams to improve access to spawning grounds, habitat restoration projects, captive breeding programs, implementing fishing regulations, and increasing public education about these species and their conservation needs help to protect and restore these species' migratory pathways.

Protected Areas

Many of the areas spared from human development are now protected, creating a patchwork of protected lands mixed throughout the landscape. The Roanoke River National Wildlife Refuge shelters one of the largest remaining bottomland swamps in the eastern United States. Alligator River and Pocosin Lakes National Wildlife Refuges in eastern North Carolina harbor remaining pockets of pocosin habitat and concentrations of migratory waterfowl and red wolves. The Great Dismal Swamp along the Virginia–North Carolina border is rumored to have been a stopover area for the notorious pirate captain Blackbeard. The Croatoan National Forest, Holly Shelter Game Lands, and Green Swamp in eastern North Carolina contain some of region's remaining longleaf pine savannas and are sanctuaries for carnivorous plants. The Francis Marion National Forest in South Carolina contains diverse blackwater swamps. The Savannah River, although developed in several areas, still contains several isolated pockets of natural habitat. The Savannah National Wildlife Refuge stretches across 30,000 acres of wildlife habitat including tidal freshwater marshes and bottomland hardwood forests, spanning across parts of South Carolina and Georgia. This is an important area for native and migratory songbirds and shorebirds, and is just one of seven wildlife refuges in this region known as the Savannah Coastal Refuges Complex. This area is a popular tourist destination and within just a few hours' drive of millions of people.

Ecoregion Threats

Despite the presence of these remaining wildernesses, this ecoregion is considered by many conservation groups to be endangered. Human development has expanded over the last decades of the twentieth century into the twenty-first century, pushing people and communities closer to wild areas. Many of the swamps have been drained to make way for farming operations. The area is crisscrossed by canals that shuttle water area from natural wetlands, creating drier areas suitable for farming. Commercial timber harvesting is also prevalent, with monotypic stands of loblolly pine covering thousands of acres. Pockets of urbanization continue to expand and encroach on natural areas.

The resulting landscape is a diverse mix of cities, suburbs, timber plantations, farms, woodlands, wetlands, and protected areas. Many ecosystems—such as longleaf pine savannas, cypress forests, and cedar swamps—have been reduced to a fraction of their former range. Both forest cover and wetland area have been reduced since the late twentieth century, whereas the amount of developed land has rapdily increased.

Although forestry and agriculture have converted much of the native habitat, many generalist wildlife species manage to thrive in these areas. Habitat destruction has led to the endangerment of several species, however, especially those that are dependent on specific habitat types. Destruction of river environments and construction of dams have reduced the populations of many anadromous fish species and altered natural water flows that feed coastal swamps.

Climate change may pose additional risks in the future, not only to wild species, but also to human populations, given that much of this area lies at or near sea level. More violent storms and hurricanes can lead to stream dislocation and advanced erosion. Higher temperatures and drier conditions that studies suggest may result here from global warming will also open the door to population booms among tree-damaging insects. These threats will be met in some cases by determined human foes, as efforts are underway to restore native habitats return to natural processes, and otherwise defend this diverse and unique ecosystem.

Bibliography

Conner, William H., et al. Ecology of Tidal Freshwater Forested Wetlands of the Southeastern United States. Springer, 2007.

Davis, Donald E. Southern United States: An Environmental History. ABC-CLIO, 2006.

Dickson, James G. Wildlife of Southern Forests: Habitat and Management. Hancock House Publishers, 2006.

"Eastern North Carolina Red Wold Population: Release Plan: Release Plan." U.S. Fish & Wildlife Service, Dec. 2024, fws.gov/sites/default/files/documents/2024-11/20241121‗enc-rwp‗release-plan‗2024-2025.pdf. Accessed 19 Dec. 2024.

Jose, Shibu, et al. The Longleaf Pine Ecosystem: Ecology, Silviculture, and Restoration. Springer Science+Business Media, 2006.

Messina, Michael G., and William H. Conner. Southern Forested Wetlands: Ecology and Management. CRC Press, 1998.

"Red Wolf Recovery Program." U.S. Fish & Wildlife Service, Sept. 2024, fws.gov/project/red-wolf-recovery-program. Accessed 19 Dec. 2024.

"Reopening Rivers for Migratory Fish." National Oceanic and Atmospheric Administration, fisheries.noaa.gov/national/habitat-conservation/reopening-rivers-migratory-fish. Accessed 19 Dec. 2024.

"Savannah National Wildlife Refuge." U.S. Fish & Wildlife Service, fws.gov/refuge/savannah/about-us#:~:text=The%20entire%20refuge%20was%20designated,birds%20and%20nursery%20habitat...&text=Tybee%20National%20Wildlife%20Refuge%2C%20located,and%20migratory%20songbirds%20and%20shorebirds. Accessed 19 Dec. 2024.

Sorg, Lisa. "Eight Red Wolves Released into the Wild in Eastern North Carolina in Hopes of Keeping the Species Intact." The Pulse, 17 May 2021, pulse.ncpolicywatch.org/2021/05/17/eight-red-wolves-released-into-the-wild-in-eastern-north-carolina-in-hopes-of-keeping-the-species-from-going-extinct/#sthash.HQQUK7fH.dpbs. Accessed 19 Dec. 2024.