Throughout South Carolina as well as in
the ACE Basin study area, significant natural areas
are designated using The
Heritage Trust Program. Nationally, the Heritage Trust Program was developed by
The Nature Conservancy (TNC) in the early 1970's. The South Carolina Department
of Natural Resources initiated a Heritage Trust Program in South Carolina in
1976. The program uses common, standards-based methodologies to collect,
maintain, and share information about endangered, threatened, or rare plants,
animals, and ecological communities. For more information, refer to
The Heritage
Trust Program's web site
.
Over the years, the staff of
South Carolina's Heritage Trust Program have recognized two hundred and
forty-six sites in the ACE Basin study area as significant natural areas
(Heritage Trust Database 1997). By definition, these are natural areas that
contain endangered or threatened animal and plant species; outstanding remnants
of an undisturbed plant community or ecosystem; unusual or outstanding
scientific, education, aesthetic, or recreational characteristics; or unique
landforms. Significant natural areas in the ACE Basin study area and throughout
South Carolina are selected through a process that involves a systematic search
for sites of high natural value (i.e., containing endangered or threatened
species), an evaluation of the sites' value, and the application of various
legal mechanisms for protecting the most highly valued sites. The first step of
the process is to identify and characterize the natural communities. Heritage
Trust staff and other professionals, including the staff of The Nature
Conservancy, naturalists, and botanists, employ aerial photo interpretation, as
well as aerial and ground survey techniques, to locate and characterize
potential natural areas. During aerial and ground surveys, the size, natural
quality (i.e., lack of disturbance), and unique character of the species or
community type are recorded. Additional information that the scientists compile
includes the total number of occurrences of the species or community type
range-wide, and the status of the species population or community types
throughout its range (i.e., increasing or declining in numbers).
Next, this information is used to evaluate the significance of the natural areas. Criteria used to rank the areas include the uniqueness of the elements (i.e., species or plant communities) and the natural quality (i.e., level of disturbance) of the sites. Sites that contain elements that are rare, threatened, or endangered throughout their range and have a high natural quality (undisturbed maritime forest) receive the highest priority. In contrast, sites that contain elements that are only rare in part of its range and have a low natural quality (i.e., ditches) are ranked as low priority sites, or not significant (Rayner 1984, TNC 1994). Other factors considered during the evaluation process include the availability of the sites and the ability of Heritage Trust to protect the sites.
Finally, various mechanisms
are employed to protect the areas that have high priority (SCDNR undated). If
possible, the State of South Carolina either buys or acquires an easement on
the high priority sites. These protected
properties
are dedicated as Heritage Preserves in perpetuity to SCDNR under
the terms of the Heritage Trust Act. Some sites are further protected by
placing them in the SC Heritage Trust. This protection specifies the public as
the beneficiary and SCDNR as the trustee. For sites that are unavailable for
purchase or a permanent conservation
easement, the State attempts to obtain a
Registration agreement in which the Heritage Trust Program and the property
owner agree to protect the natural area by appropriate management. However,
these agreements are voluntary and may be canceled with a thirty-day notice
(SCDNR undated). In addition, the Heritage Trust staff employs the Threatened
and Endangered Species Act to protect the habitat of endangered and threatened
species.
Sites of Significance in the ACE Basin
- Sites with Endangered and Threatened Species Habitat
- Sites with Species of Concern Habitat
- Sites with Outstanding Remnants of Plant Communities
- Sites with Outstanding Scientific Characteristics
The two hundred and forty-six significant natural areas in the ACE Basin study area differ in size, natural quality, and uniqueness in regard to species and community type. Some of these natural areas are as small as a few square feet (i.e., a bald eagle nesting site). Others are larger than a thousand acres (i.e., Snuggedy Swamp). The quality of the natural areas in the Basin varies from highly disturbed to pristine (e.g. Otter Island). Some areas contain federally or state endangered or threatened species. Other sites include species that may be threatened or endangered in their range. Consequently, the priority ranking of ACE Basin study area's natural areas ranges from national to local significance.
Sites with Endangered and Threatened Species Habitat
Eighty-three of the two hundred and
forty-six significant natural areas
harbor five federally endangered or
threatened species
and twelve sites provide habitat for two state threatened
species. Ten natural areas serve as nesting, roosting and feeding habitats for
the wood stork
(Mycteria
americana), a federally endangered species, and three are active rookeries
(See wading birds
). The
rookery
near Jacksonboro, was the first known wood stork nesting colony in
South Carolina (Dodd and Murphy 1997). Since 1981, the average colony size has
increased from twenty to one hundred and two nests. By 1996, the number of
colonies in the ACE Basin study area had increased to three. Roosting and
feeding habitats are primarily located near impoundments
and shallow creeks of
the ACE Basin study area where the birds feed on fish. One natural area within
the ACE Basin study area harbors the federally endangered
Canby's dropwort
(Oxypolis
canbyi), one of twenty-five populations of this species remaining in the
United States (Murdock and Rayner 1989). The plant grows in wet depressions
within the Cowbane Heritage Preserve, a state-owned property in Colleton County
(Rayner 1984). The depressions are scattered throughout the swamp communities
that dominate the Preserve. Shortnose
sturgeon
(Acipenser brevirostrum), the third federally endangered
species, utilizes the South Edisto River as a feeding habitat.
In 1996, twenty-eight nesting
pairs of federally threatened bald eagle (Haliaeetus leucocephalus) were
utilizing sixty-six sites as nesting, roosting, and feeding habitats.
Bald eagles
usually nest within a
mile of estuarine rivers and impoundments of the ACE Basin NERR, and the nest areas
are less than 0.4 hectares (one acre) in size (USFWS 1987,
Charlotte Hope, SCDNR Wildlife and Freshwater Fisheries Division, pers. comm.).
Nests are found in the tops of the tallest and largest loblolly pines in pine
and mixed hardwood-pine forests of the ACE Basin study area. Most of the
roosting trees and feeding habitats are within the watersheds of the Combahee
and South Edisto Rivers. The federally threatened
loggerhead sea turtles
(Caretta caretta) use several natural areas.
Nesting sites
for this species in South Carolina are on the beaches of Edisto,
Otter and Harbor islands.
Two statewide threatened species, Wilson=s plover (Charadrius wilsonia) and the least tern (Sterna antillarum), reside in the ACE Basin study area. Both species nest on Edisto Beach, and least terns have also been found nesting on a bird key (small island in St. Helena Sound) near Harbor Island. (See related sections: Birds: Beach Community and Bird Keys .)
Sites with Species of Concern
Habitat
Sixty significant natural areas
within
the ACE Basin study area harbor species of concern (Species of concern
). The twenty-seven species of plants and
animals may be threatened or endangered on a national, regional or state level.
Current data suggest that their populations in the may be declining due to
habitat loss, alteration, or pollution. Seventeen species inhabit shallow
freshwater wetlands; each year, acres of shallow wetlands are drained for crop
production, timber production, and mosquito control (The Governor's Office
1990). Another six species inhabit maritime communities on coastal islands,
where residential development is increasing (Water Resources Division 1996).
Five of the species (eastern creekshell, barred pygmy sunfish, Cooper's hawk,
green-fly orchid, and crested-fringed orchid) are included because few data
exist to adequately evaluate their status. Although their numbers are
increasing in the state, the brown
pelican
is still a species of concern (Williams 1976). To date, the only
known pelican colony in the ACE Basin study area is on Deveaux Bank, a
multi-colony site that large number of shorebirds, including black skimmers,
royal terns, least terns, and laughing gulls also use (Tom Murphy, SCDNR
Wildlife and Freshwater Fisheries Division, pers. comm.).
Sites with Outstanding Remnants of Plant Communities
Thirty-three natural areas
are recognized as outstanding examples of coastal plant communities (Plant communities
in the ACE Basin study area. The Nature
Conservancy initially characterized the communities within the ACE Basin
watershed
(TNC 1993). Twelve of these significant natural areas are maritime
and upland communities, and the remaining sites are estuarine
and freshwater
wetlands. The maritime and estuarine communities are within the ACE Basin
National Estuarine Research Reserve (NERR), which contains some of the largest
undeveloped estuarine wetlands on the East Coast. A diverse group of
representative outer coastal plain plant communities characterizes the Reserve,
including the full array of communities typically associated with barrier
islands, marsh islands, and estuarine rivers. Especially well represented are
estuarine and maritime communities. Many freshwater wetlands are found in a
relatively undisturbed region of Snuggedy Swamp which is near the
saltwater-freshwater transition zone on the South Edisto River. This
930-hectare (2,300-acre) parcel of swamp represents the largest
grass-sedge-marsh/loblolly-bay complex in South Carolina. Aerial surveys show
that most of Snuggedy Swamp is a mosaic of freshwater marsh and swamp
communities with a few small ponds and 'islands' scattered throughout the area.
Other representative sites of coastal plain communities are on the large
plantations (more than 400 hectares in size) that border the rivers and creeks
of the ACE Basin study area.
One natural area in the study area is the relatively undisturbed Otter Island, a 1,300-hectare (3,232-acre) barrier island. The island encompasses a full array of maritime estuarine, and palustrine communities, including dunes, maritime forests, Spartina marshes, and fresh to brackish ponds. The island has several nesting colonies of rare birds and populations of rare plants.
Sites with Outstanding Scientific Characteristics
Fifty-seven of the natural areas
have outstanding scientific
characteristics. They include rookeries and feeding habitats of colonial
waterbirds such as the great blue heron and its allies (i.e., great egret,
little blue heron, tri-colored heron, glossy ibis, white ibis). The U.S. Fish
and Wildlife Service conducted a survey of these birds in 1975 to determine
their status and distribution along the Atlantic Coast (Custer and Osborn
1978). Previous studies suggested a correlation between nesting success and
environmental conditions such as water quality. Therefore, the birds are a good
biological indicator
(a population or assemblage of populations that reflects
the ecological health of the environment). A more extensive survey was
initiated in 1988, by the South Carolina Department of Natural Resources,
Freshwater Fisheries and Wildlife Diversity Division, to quantify normal
fluctuations in colony location and species abundance and to characterize
habitat and reproductive successes (Dodd and Murphy 1997). These data will be
used to determine the relationship between nesting success of
waterbirds
and environmental conditions.
Heritage Trust staff continuously updates information about natural areas as new occurrences are found, existing populations change, and the status of species or plant communities are reclassified. The Heritage Trust Program relies on the assistance of professionals that can track and document the occurrences of rare species and communities. The staff will provide technical guidance and appropriate forms and maps to all who are interested in helping with this process.
Author
S. Upchurch, SCDNR Marine Resources Research Institute
Custer, T.W. and R.G. Osborn. 1978. Wading birds as biological indicators: 1975 colony survey. United States Department of Interior, Fish and Wildlife Service. Special Scientific Report - Wildlife No. 206. Washington, DC.
Dodd, M.G. and T.M. Murphy. 1997. The status and distribution of wading birds in South Carolina, 1988-1996. The Chat 61(3): 129-181.
Heritage Trust Database. 1997. List of threatened and endangered species. South Carolina Department of Natural Resources, Freshwater Fisheries and Wildlife Diversity Division.
Martof, B.S., W.M. Palmer, J.R. Bailey, and J.R. Harrison III. 1980. Amphibians and reptiles of the Carolinas and Virginia. University of North Carolina Press, Chapel Hill.
Murdock, N. and D. Raynor. 1989. Agency draft recovery plan for Canby=s dropwort (Oxypolis canbyi [Coulter and Rose] Fernald). U.S. Department of the Interior, Fish and Wildlife Service. Atlanta, Georgia.
Porcher, R.D. 1995. Wildflowers of the Carolina Lowcountry and lower Pee Dee. University of South Carolina Press, Columbia.
Potter, E.F., J.F. Parnell, and R.T. Teulings. 1980. Birds of the Carolinas. University of North Carolina Press, Chapel Hill.
Radford, A.E., H.E. Ahles, and C.R. Bell. 1968. Manual of the vascular flora of the Carolinas. The University of North Carolina Press, Chapel Hill.
Rayner, D.A. 1984. Inventory of botanical natural areas in Colleton County, South Carolina. In Inventory of botanical natural areas in Colleton, Dorchester, Horry, and Jasper counties, South Carolina. South Carolina Wildlife and Marine Resources Department, Division of Wildlife and Freshwater Fisheries, Heritage Trust Section, Columbia, SC.
Rohde, F.C. and R.G. Arndt. 1987. Two new species of pygmy sunfishes (Elassomatidae, Elassoma) from the Carolinas. Proceedings of The Academy of Natural Sciences of Philadelphia 139: 65-85.
The Governor=s Office. 1990. Report of the Governor=s Freshwater Wetlands Forum. The Governor=s Office, Division of Energy, Agriculture and Natural Resources. 1205 Pendleton Street, Columbia, South Carolina.
[NOAA] National Oceanic and Atmospheric Administration. 1992. Ashepoo-Combahee-Edisto (ACE) Basin National Estuarine Research Reserve in South Carolina, Final Management Plan. U.S. Department of Commerce, NOAA, National Ocean Service, S.C. Coastal Council, and S.C. Wildlife and Marine Resources Department.
SCDNR. undated. South Carolina Heritage Trust brochure. Published by SC Wildlife and Marine Resources Dept (currently SCDNR).
TNC. 1993. ACE Basin biological inventory report, 1990-1992. The Nature Conservancy. Charleston, South Carolina.
TNC. 1994. Rare plant communities of the conterminous United States. Prepared by The Nature Conservancy, Arlington, South Carolina. Prepared for the U.S. Fish and Wildlife Service.
USFWS. 1987. Habitat management guidelines for the bald eagle in the southeast region. U.S. Department of the Interior, Fish and Wildlife Service. Atlanta, Georgia.
Water Resources Division. 1996. Managing resources for a sustainable, the Edisto River Basin project report. Sponsored by the United States Department of Commerce, National Oceanic and Atmospheric Administration. Published by the South Carolina Department of Natural Resources, Columbia.
Webster, W.D., J.F. Parnell, and W.C. Biggs, Jr. 1985. Mammals of the Carolinas, Virginia, and Maryland. University of North Carolina Press, Chapel Hill.
Williams, L.E. 1976. Recovery plan for the eastern brown pelican (preliminary draft). U.S. Department of the Interior, Fish and Wildlife Service. Atlanta, Georgia.