All about Atlantic white cedar

Atlantic White Cedar, [Chamaecyparis thyoides (AWC)] is native to the Atlantic coast of North America from Maine to Georgia with a separate population on the Gulf of Mexico coast from Florida to Mississippi (Laderman 1989). It is a coniferous, evergreen tree species that exists in pure stands as a consequence of major disturbance, such as fire or weather-related blow-down.

Atlantic white cedar is an obligate wetland species (Natural Resources Conservation Center 2012) that grows best when the water table is within 4 to 8 inches of the soil surface during the growing season (Little 1950). It can tolerate short-term flooding during the growing season (Golet and Lowry 1967), but unlike baldcypress, is intolerant of long-term, deep water flooding. Drainage of wetlands in the 19th and 20th centuries played an important role in the decline of Atlantic white cedar and cypress (Frost 1987; Krinbill 1956). Even today, excessive drainage appears to be the likely cause of high Atlantic white cedar mortality in some stands (Laderman 2012); in other situations, impeded water movement, most often by road beds, can also have negative effects. Drainage of swamps for agriculture greatly contributed to the demise of Atlantic white cedar and cypress by permanently altering the hydrology of large areas, and by changing the frequency and severity of wildfires (Frost 1987; Lilly 1981).

Pure AWC stands owe much of their existence to fire, but fire at too frequent intervals will destroy them (Frost 1987). In Atlantic white cedar stands, good forest management practices, combined with appropriate management of soil water table levels, alter the frequency and severity of fires to achieve desired objectives while minimizing the risk of catastrophic loss. A high water table, however, does not guarantee immunity from fire; head-fires can travel through tree crowns, resulting in complete destruction (Little 1946). If water tables can be maintained near or just above the soil surface, fires that do occur likely will burn small blocks of trees, depending on the micro-topography, resulting in a patchwork mosaic of stands in the landscape. These groups, in turn, can subsequently provide seed to regenerate adjacent areas. Alternatively, when the peat is dry to considerable depth, fires tend to wipe out the forest over large areas, leaving no seed source for regeneration.

When settlers arrived along the eastern coast, there was an estimated 0.5 million acres of the AWC type (Kuser and Zimmermann 1995). The greatest concentrations of AWC were in The Great Dismal Swamp (NC/VA), eastern North Carolina, and southern New Jersey. In the late 1990s, the acreage of pure AWC (more than 50% of the stems = AWC) was estimated to be less than 50,000 (Sheffield et al. 1998). Since 2003, hurricanes (Isabelle and Sandie) struck eastern North Carolina and southern New Jersey, resulted in major losses in the acreage of AWC stands (Lowie et al. 2009). Extensive losses following Hurricane Isabelle have occurred in southern New Jersey as a result of what is believed to be salt injury. Compounding these losses were two large fires in the Great Dismal Swamp during efforts to salvage AWC damaged or destroyed by Hurricane Isabelle (Lowie et al. 2009). No recent inventory is available, but the current acreage of the AWC type is believed to be well below estimates for the late 1990s.

Revised 28 October 2013
Eric Hinesley

For more information about this species, its habitat, range, natural history and wood qualities, please visit the For Researchers section of this website.

Atlantic White Cedar Initiative
Campus Box 8008, Raleigh, NC 27695-8008
919-515-9563, 919-515-7793
info@atlantic-white-cedar.org