releve Virginia Division of Natural Heritage, see http://www.dcr.virginia.gov/natural_heritage/documents/nh_plotform_instructions.pdf
Overall Taxon Cover Values are Automatically Calculated?
no
Stem Observation Area
400
m²
Plot Quality Fields:
Plot Validation Level
(2) classification plot: sufficient for inclusion in a classification revision
Overall Plot Vegetation Fields:
Tree Height
9
m
Shrub Height
6
m
Field Height
8
m
Tree Cover
55
%
Shrub Cover
45
%
Field Cover
45
%
Nonvascular Cover
50
%
Misc Fields:
Observation Narrative
The plot captures the very open woodland / barren vegetation on a steeply dipping sandstone outcrop on the upper SE flank of Bald Mountain above Barbours Creek. This barren is large, covering ca. 5.5 ha (13.7 acres), and in nearly pristine condition; the only signs of disturbance noted were several very old, cut cedar stumps. The underlying Ridgely Formation sandstone is well exposed at this site and distinctly calcareous; however, despite the substrate and the presence of several pronounced calciphiles, soil collected from a plot had very low calcium, along with very high manganese and aluminum levels (bases were perhaps leached from the thin veneer sampled). Stunted trees (< 10 m tall) are mostly Juniperus virginiana, Quercus stellata, Carya glabra, Fraxinus americana, Pinus virginiana, and Quercus montana. Shrubs are scattered and include Cercis canadensis, Celtis tenuifolia, Rosa carolina, and Chionanthus virginicus. The herb layer varies from sparse in outcrop areas to dense in areas where thin soils have accumulated. Herbaceous dominants are Schizachyrium scoparium, Carex pensylvanica, and Danthonia spicata. Also present are Andropogon gerardii, Sporobolus clandestinus, Elymus hystrix, Aristida dichotoma, Houstonia longifolia, Helianthus divaricatus, Ambrosia artemisiifolia, Packera anonyma, Agalinis tenuifolia, Dodecatheon meadia, Allium cernuum, Solidago ulmifolia, Commelina erecta, and Phacelia dubia. Lithophytic herbs more strongly associated with pavements and outcrop crevices include Talinum teretifolium, Polygonum tenue, Cheilanthes lanosa, Selaginella rupestris, Hypericum gentianoides, Bulbostylis capillaris, Cyperus lupulinus, Pellaea atropurpurea, Trifolium virginicum, Sedum glaucophyllum, and Woodsia obtusa. Bryophytes and lichens are abundant on both soil and rock outcroppings.
