Blue Ridge Low-Elevation Quartzite Outcrop
Southern Appalachian Rocky Summit (NatureServe 2014)
Low-Elevation Acidic Outcrop Barrens (Fleming 2015)
Eastern Tennessee (Carter, Greene and Unicoi counties), in seams along side-slopes and ridges at mid-elevation.
Blue Ridge quartz outcrops occur as thin, linear strip communities. Sparsely vegetated, they are likely dominated by a combination of low-growing, xerophytic forbs and graminoids as well as a suite of lithophytic lichens. Oak woodland and forest surrounds, with shrubs occupying the interface of woodland and outcrop. Vegetation typically reaches less than a meter in the outcrop proper.
This system occurs in the Southern Sedimentary Ridges level IV ecoregion of the Blue Ridge Mountains (Griffith et. al 1998). Outcrops occur on moderately steep slopes (>20°) at mid-elevation, 700 to 850 meters (2300 to 2750 feet), and mostly run to the northeast along with the mountain chains they associate. Highly erosive resistant, the Cambrian age, metamorphic quartzite rock (Erwin and Chilhowee Formations) (Hardeman 1966) protrudes in relief from associating geologies of the landscape, forming long chains that run along side-slopes. Soils are acidic, very thin and likely derive from the parent quartzite or the more erosive surrounding sandstones. They occur in a soil matrix of Ramsey Stoney Loam, Ditney Loam, and Unicoi-Rock outcrop (Web Soil Survey, 2015).
Edaphic conditions are largely responsible for the maintenance of this system. Surrounding woodland and forest are likely fire-dependent.
Potential rare species include:
Diervilla sessilifolia var. rivularis (mountain bush honeysuckle)
Woodsia appalachiana (Appalachian cliff fern)
Carex argyrantha (hay sedge)
Community Variation and Subtypes
1) forest-outcrop edge: dominated by ericaceous shrubs, otherwise barren species in thinner soil; 2) deep-soil fissures: may be occupied by stunted tree species; 3) pavement outcrop: dominated by lithophytic lichens and scattered or patchy mats of xerophytic herbs (Fleming 2015).
Associated Natural Communities
Blue Ridge Low-Elevation Quartzite Blockfield, , Blue Ridge Quartzite Cliff, Blue Ridge Dry/Xeric Acidic Shale Woodland, Blue Ridge Low-Elevation Rocky Sandstone Shrubland, Blue Ridge Dry/Xeric Acidic Sandstone Woodland
Blue Ridge Low-Elevation Quartzite Blockfield, Blue Ridge Low-Elevation Sandstone Outcrop
Presettlement Distribution and Size
Habitat distribution and total size for this system has likely remained fairly stable.
These outcrops appear to be fairly scattered, limited in size and few in number. Less than 10 sites were located using aerial imagery.
Carter Co.: Hampton (36°17'8.91"N, 82°11'12.54"W)
Because of their location and scenic value, residential development poses a potential threat to these outcrops.
Prescribed burns of the woodlands and forest may help open up habitat.
Future Research Needs
Baseline floristic inventories and plot work are required for this unknown system.
To our knowledge, no studies of this system exist.
Fleming, G.P. "The Natural Communities Of Virginia Classification Of Ecological Community Groups: Appalachian Shale Barrens" Virginia Department of Conservation and Recreation. http://www.dcr.virginia.gov/natural_heritage/natural_communities/ncTIVf.shtml 12 Jan 2015.
Griffith G, Omernik J, Azevedo S. 1998. Ecoregions of Tennessee (color poster with map, descriptive text, summary tables, and photographs): Reston, VA., U.S. Geological Survey (map scale 1:1,000,000).
Hardeman, W.D., and others, 1966, Geologic map of Tennessee: Division of Geology, Tennessee Department of Environment and Conservation, scale 1:250,000
NatureServe. 2015. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org. (Accessed: March 27, 2015 ).
Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Web Soil Survey. Available online at http://websoilsurvey.nrcs.usda.gov/. Accessed [05/4/2015].
Checklist of Plant Species known from this community