North Carolina
This site is one of the best remaining examples of a Southern Appalachian Bog, a group of communities that are somewhat different from either bogs or fens in the glaciated north. They are fens in the sense that ground water is a major hydrological influence, but the acidic rocks that make up most of the southern Appalachians combined with the deep weathering of the substrate make for highly acidic ground water. The flora is more bog-like than fen-like.
McClures Bog is located on the edge of the bottomland of a low gradient stream, with a muck soil that has developed over older alluvium. Ground water seepage comes from the adjacent upland, and a natural levee cuts off flood influences from the creek. The natural levee probably also blocks outflow of both rain water and seepage from the wetland. A small creek brings in some surface water. The vegetation is a fine mosaic of tree clumps, shrub thickets and open herb-dominated areas, with extensive sphagnum beds beneath the other vegetation. Herb areas are dominated primarily by sedges and ferns, but a variety of characteristic forbs and grasses are present. The flora includes Southern Appalachian endemics, species characteristic of northern bogs, species disjunct from bogs of the Coastal Plain of Southeast, as well as widespread species of acidic wetlands.
The site is located in the southeastern part of the North Carolina Blue Ridge, in the broad, flat valley of the upper French Broad River, near Hendersonville. It is a remnant of the once largest collection of Southern Appalachian Bogs in existence, now largely destroyed by urban development and drainage.
4 rare plants and one rare animal species. 2 of the plants are federally listed, one is a G1.
Major Threats: Succession, Maintaining the hydrologic system, Water quality
The major known threats are succession to more woody vegetation, input of sediment and nutrients from adjacent uplands, and disruption of ground water input by activities on adjacent uplands. Exotic plants, including Chinese privet (Ligustrum sinense), Japanese honeysuckle (Lonicera japonica), and microstegium (Microstegium vimineum) are established in the buffer zone and have encroached into the bog in places.
The rare plants and animal, as well as the character of the community, are highly threatened by the expansion of cover of the native shrubs, which are species that are widespread in southern Blue Ridge wetlands. This process resembles natural succession, but likely is driven by reduction of wetness and by excess nutrient input. It is most severe in areas with sediment input in surface water. The site was pastured before being acquired by the Nature Conservancy, and it is not known what lasting effect that may have had. It has been hypothesized that trampling by cattle may have stirred underlying mineral soil into the shallow organic layer and increased its nutrient content.
Major Science and Stewardship Activities
Hydrologic restoration: Drainage tiles in an adjacent old field have been removed, in hopes of restoring wetland conditions there. Silt fences and check dams below an existing farm pond have had limited success in blocking sediment input. Creation of meanders in the small stream above the pond is being considered.
Shrub cutting to reclaim openings: Invaded trees in the interior are being girdled to increase sunlight without increasing nutrient load.
Sphagnum planting: Lack of spahgnum may be a limiting factor in reproduction of the most significant rare plant. A sphagnum nursery is being considered.
Ongoing hydrologic monitoring
For more information, please contact:
TNC of North Carolina
P.O. Box 397
Saluda, NC
28773
(828) 749-1700
or email at: estifel@tnc.org