Great Dismal Swamp Ecology

• Category: Inland Aquatic Biomes.
• Geographic Location: North America.

Summary: The Great Dismal Swamp is a large wetlands area in the southeastern United States, located along the border between Virginia and North Carolina. Comprised of more than 100,000 acres (40,500 hectares) of forested wetlands, it also holds the largest natural lake in Virginia. Centuries of logging and drainage operations devastated the swamp's rich ecosystems, but the Great Dismal Swamp National Wildlife Refuge was established in 1974 to restore and protect its biodiversity. The swamp is also notable for its historical use as a refuge for American Indians and formerly enslaved people.

Geography and Climate

The Great Dismal Swamp is both beautiful and hazardous, and unique in many ways. While most swamps exist in the lowest elevations of a region, where water accumulates faster than it drains, the Great Dismal Swamp is on a hillside 20 feet (6 meters) above sea level. Lake Drummond, a 3,100-acre (1,250-hectare) natural lake, is situated in the center, and seven rivers flow outward from it.

In most swamps, water, heat, and darkness combine to cause the rapid decay of vegetation. In the Great Dismal, the water is so acidic from leaching of juniper and cypress trees that there is little bacterial growth to cause decay. Debris continues to accumulate every year, making this one of the few places in the southern United States where peat forms. Dense vegetation and an abundance of food make the Great Dismal Swamp an ideal home for a wide variety of wildlife.

The area generally has mild winters and warm humid summers. Winter temperatures average above 36 degrees F (two degrees C); summer temperatures typically average above 78 degrees F (26 degrees C), with high humidity.

History and Human Impact

Human occupation of the area dates back about 13,000 years, but by 1650, only a few Native American and European settlers could be found inhabiting the edges of the swamp. In 1665, William Drummond, the first governor of North Carolina, discovered the lake that was eventually named for him. William Byrd II led a surveying party through the swamp while calculating the dividing line between Virginia and North Carolina in 1728, and is credited with naming it the Dismal Swamp.

George Washington visited the area in 1763 and had a very different opinion. He saw great opportunity, and organized the Dismal Swamp Land Company to drain the swamp and clear it for settlement. Later, the group turned to the more profitable venture of logging enormous stands of cypress, juniper, and cedar trees. A 5-mile (8-kilometer) canal was dug through the western side of the swamp to Lake Drummond for shipping shingles and other wood products. By 1795, more than 1.5 million cedar shingles were being cut per year. Additional canals followed, and a railroad was laid through part of the swamp in 1830.

Washington and other developers used slave labor and also hired poor White people to work in the swamp. It was hard and dangerous work, done in muddy ooze while coping with mosquitoes, yellow flies, and poisonous snakes. Some enslaved people were able to gain their freedom by working as bondsmen for the loggers; others escaped captivity and took refuge in the swamp. Eventually, the area became part the Underground Railroad. Some islands in the swamp also became home to permanent or semi-permanent communities of self-liberated African Americans and their descendants (often known as "maroons") until after the American Civil War. The isolated, secretive nature of these settlements contributed to the mysterious, almost mythic reputation of the swamp, which inspired many poems and books; its role as a refuge for freedom-seekers was featured in Harriet Beecher Stowe's novel Dred: A Tale of the Great Dismal Swamp, (1865), for example. In 2021, a group called the Great Dismal Swamp Stakeholders Collaborative, representing descendants of those who had lived cut off from the world in the swamp, lobbied Congress to grant the swamp recognition in honor of their ancestors' pursuit of freedom.

While early efforts to drain the swamp were often in vain, logging operations were far more successful. Timber was harvested continually from the 1700s through 1973. More than 200 years of exploitation drastically altered the wetland. Agricultural and commercial development encroached on the swamp's boundaries, reducing it to half of its original size. The entire swamp has been logged at least once, and many areas have been burned regularly by wildfires. Roads and canals also disrupted the natural hydrology of the area.

In the mid-20th century, conservation groups demanded that something be done to preserve the remainder of the Great Dismal Swamp. In 1973, Union Camp Corporation, a large landowner since the early 1900s, donated more than 49,000 acres (19,800 hectares) of swamp to the Nature Conservancy. The land was transferred to the U.S. Fish and Wildlife Service the following year, and the Great Dismal Swamp National Wildlife Refuge was officially established.

The primary purpose of the refuge resource management program is to restore and maintain the natural biological diversity that existed before commercial exploitation. Water, native vegetation, and diverse wildlife are essential to the swamp ecosystem. Water levels and water movement are being returned to their natural states. Plant diversity is being enhanced by careful forest management activities, including selective cutting and prescribed burns to reestablish native species. Wildlife management includes monitoring required habitats, with selective hunting used as a tool to balance some animal populations with available food supplies.

Wildlife

Today, the Great Dismal Swamp lies entirely within the Middle Atlantic coastal forests ecoregion. Eight major plant communities compose the swamp vegetation; the forested types include Atlantic white cedar, tupelo bald cypress, sweetgum-oak poplar, maple blackgum, and pine. The nonforested types include remnant marsh, sphagnum bog, and evergreen shrub communities. Tupelo bald cypress and Atlantic white cedar, formerly predominant forest types in the swamp, today account for less than 20 percent of the total cover. Three rare plants that thrive in the swamp are the dwarf trillium, the log fern, and silky camellia.

The swamp is still home to many mammal species, including whitetail deer, black bear, bobcat, otter, and weasel. More than 200 bird species and 70 reptiles and amphibians can also be found here. Although the Great Dismal Swamp can never be returned to its condition prior to European exploration and settlement, it is considered on the rebound. The wildlife refuge supports important populations of native flora and fauna, while also being maintained for recreational purposes such as camping, boating, fishing, and hunting.

Bibliography

Badger, Curtis J. A Natural History of Quiet Waters: Swamps and Wetlands of the Mid-Atlantic Coast. Charlottesville: University of Virginia Press, 2007.

Blackburn, Marion. “Letter from Virginia: American Refugees.” Archaeology 64, no. 5 (2011).

Davis, Hubert J. The Great Dismal Swamp: Its History, Folklore, and Science. Murfreesboro, NC: Johnson Publishing, 1971.

Flynn, Meagan. "The Great Dismal Swamp Was a Refuge for the Enslaved. Their Descendants Want to Preserve It." The Washington Post, 11 Apr. 2021, www.washingtonpost.com/history/2021/04/11/great-dismal-swamp-slavery-descendants/. Accessed 22 Nov. 2024.

Grant, Richard. “Deep in the Swamps, Archaeologists Are Finding How Fugitive Slaves Kept Their Freedom.” Smithsonian Magazine, Sep. 2016, www.smithsonianmag.com/history/deep-swamps-archaeologists-fugitive-slaves-kept-freedom-180960122/. Accessed 21 Nov. 2024.

Levy, Gerald F. “The Vegetation of the Great Dismal Swamp: A Review and an Overview.” Virginia Journal of Science 42, no. 4 (1991).

Simpson, Bland. The Great Dismal: A Carolinian's Swamp Memoir. Chapel Hill: University of North Carolina Press, 1990.

U.S. Fish and Wildlife Service, Region 5. Great Dismal Swamp National Wildlife Refuge and Nansemond National Wildlife Refuge. Suffolk, VA: U.S. Fish & Wildlife Service, 2006.