The next generation of biological carbon sequestration work is taking place at three national wildlife refuges near Albemarle Sound in North Carolina and Virginia with help from almost a dozen partners.
The refuges—Alligator River, Great Dismal Swamp and Pocosin Lakes— are bound by an ancient ecosystem called pocosin, the Algonquin Indian word for “swamp on a hill.” The refuges comprise 375,000 acres, the largest ownership of pocosin wetlands in the eastern United States.
Beneath forests of pond pines, white cedars and a dense shrub understory, the chocolate–colored soils are layered with thousands of years of slowly decaying organic material. The most precious ingredient in these pocosins, or peatlands, is the carbon–rich peat soil.
Despite comprising only three percent of Earth’s land area in places that include Alaska, Canada and Russia, “peatlands hold one–third of the world’s carbon,” Curtis Richardson of the Duke University Wetland Center said at a partner meeting this spring at Pocosin Lakes National Wildlife Refuge. Richardson is leading cutting–edge research at the refuge to quantify peat soil carbon storage.
The goal of keeping that carbon locked away has rallied a long list of U.S. Fish and Wildlife Service partners playing important science or funding roles. They include The Nature Conservancy (TNC), The Conservation Fund, the states of North Carolina and Virginia, the National Oceanic and Atmospheric Administration, the U.S. Geological Survey, the Environmental Protection Agency, and Duke, Christopher Newport and North Carolina State universities.
Sara Ward, an ecologist with the Service’s Environmental Contaminants Program in the Raleigh ecological services field office, compared the effort to an old–fashioned barn–raising. “With limited budgets, we’re pulling together lots of different resources, looking for help and ways to help our partners.”
Under natural conditions, the peat soaks up rainfall and the carbon remains stable, locked away in the deep soils that reach 12 feet or more below the surface.
But starting in the 1700s, swaths of Albemarle Sound were ditched and drained for farms and pine plantations. George Washington was a famous early proponent of the practice to harvest Atlantic white cedar and bald cypress from Great Dismal Swamp.
Without enough water, the peat dries up, releases carbon (a climate–changing greenhouse gas) and becomes a fire hazard. While healthy pocosins need periodic fire, drainage makes them vulnerable to severe fires that burn underground, particularly during drought years. Last year, fires ignited in Alligator River and the Great Dismal Swamp Refuges burned about 52,000 acres combined. In addition to the ecological and greenhouse gas impact, the fires are costly: Fire suppression at the three refuges has cost more than $50 million since 2008. Furthermore, the loss of soil and associated elevation makes these low–lying coastal refuges more susceptible to sea–level rise.
The solution is to return the water to the peatlands and mimic natural seasonal fluctuations by installing water control structures in some of the thousands of ditches. In addition to storing carbon, re–wetting the pocosins is good for wildlife, water quality, nearby human communities and increased resiliency to climate change.
TNC is attracting donors and recently matched a $250,000 investment by the Service to restore the hydrology at Alligator River and Great Dismal Swamp Refuges. Pocosin Lakes Refuge has already restored 20,000 acres of pocosin wetlands, which are retaining an estimated 130 million pounds of carbon annually. That’s equivalent to 11,000 cars’ emissions. Restoration of 15,000 more acres is planned.
Katherine D. Skinner, executive director of TNC’s North Carolina chapter, said “understanding and restoring the hydrology on [Alligator River and Great Dismal Swamp Refuges], in addition to the work in place at Pocosin Lakes Refuge, is monumental to advance good conservation and minimize the effects of climate change as much as possible.”
Stacy Shelton is a public affairs specialist in the Southeast Region office in Atlanta.
