Ohoopee Dunes: A study in nature, sand
By Mincy Moffett
Ohoopee Dunes Natural Area is one of Georgia's most significant natural communities and floristic areas. The natural area comprises three tracts in southwestern Emanuel County. The Georgia Department of Natural Resources also cooperates in managing an adjacent tract owned by The Nature Conservancy and another nearby tract owned by the U.S. Fish and Wildlife Service. Together, these five conservation lands, arranged in an archipelago-like fashion along the eastern boundary of the upper Little Ohoopee River, encompass nearly 3,000 acres.
The central topographic feature of all the tracts is a spine or ridge of Kershaw sand dunes. In Georgia, sand dunes or sandhills can be found at the seashore, the fall line and along the eastern banks of Coastal Plain rivers and streams. The dunes along riverbanks and streams are also known as riverine sandhills.
The sandhills along the seashore mark current coastlines, while those found along the fall line show where ancient coastlines were. Unlike coastal areas and the fall line, riverine sandhills were created over time as strong westerly winds deposited exposed river bottom sand along the eastern shore of certain rivers. The most extensive riverine sandhill formation in Georgia is the Ohoopee River dunes system. It includes more than 65 linear miles of oval-shaped dunes along the Little Ohoopee and Ohoopee rivers, extending from just northwest of Swainsboro to the junction with the Altamaha River and encompassing approximately 22,000 acres.
Ohoopee Dunes Natural Area has several natural communities, ranging from dry (xeric) dunes and longleaf pine forests to moist hardwood hammocks and river floodplains. The visually dominant natural community is the xeric dune system dominated by longleaf pine (Pinus palustris), wiregrass (Aristida beyrichiana) and turkey oak (Quercus laevis). Turkey oak, the signature plant species of the dunes, is a sandy soil generalist adapted to a variety of dry sandy habitats. The rare few-flower gayfeather (Liatris pauciflora) found at Ohoopee Dunes is also a generalist.
Some species found at this natural area are sandhill specialists and are, therefore, found only on dunes and sandhills. Such is the case with the sandhill milk-vetch (Astragalus michauxii), state-listed as threatened. Perhaps the most interesting plants are those species found at Ohoopee Dunes and on the coasts of other southern states, but which are absent from the coast of Georgia. This group includes scarlet sage (Calamintha coccinea), woody goldenrod (Chrysoma pauciflosculosa) and the sandhill rosemary (Ceratiola ericoides), state-listed as threatened.
The sandhill rosemary is a fragrant wood shrub that is highly flammable and depends on fire for successful reproduction. Fire plays an important role in the health of sandhill communities. Burns are typically patchy, because fuels on the ground (leaves, litter and branches) are sparse and fire does not carry across bare sand. Fire leaves a patchy appearance, with many islands of vegetation remaining unburned.
Many of the unique and rare species on sandhills and in the ecotones, or habitat transition zones, need fire to live. The Indian olive (Nestronia umbellula), state-listed as rare, is found in the ecotones between sandhill and hammock forests, and may benefit from periodic fire. The green-fly orchid (Epidendrum conopseum), state-listed as unusual, is likely unaffected by most fires as it inhabits the shaded branches of trees in moist forest hammocks.
Sandhills are also home to many highly specialized animals, including the eastern indigo snake (Drymarchon corais couperi), federally-listed as threatened; the gopher tortoise (Gophermus polyphemus), state-listed as threatened; and an insect endemic to this area, the Ohoopee Dunes moth (Narraga georgiana).
Rare and interesting animal species are also associated with wetland and aquatic habitats at Ohoopee Dunes Natural Area, including the striped newt (Notophthalmus perstriatus), state-listed as threatened, and the ironcolor shiner (Notropsis chalybaeus).
This area has been the subject of scholarly research by the Canadian Museum of Nature (Ottawa), the Florida Department of Agriculture, Georgia Southern University, Mississippi State University and the University of Georgia.
The primary management objective for this property is the protection of rare species populations and natural communities of plants and animals. Public access is also provided for hunting, fishing, hiking, wildlife observation, scientific research and environmental education.
Caution: The trail system, consisting of un-maintained primitive roads, provides a limited hiking network. If hiking off-trail, please take a map and compass. It is easy to lose your bearings in the thick bottomlands and stunted turkey-oak forests.
Mincy Moffett, who has a doctorate in plant ecology, is a botanist and wildlife biologist with the Wildlife Resources Division's Nongame Conservation Section.