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
Plot Quality Fields:
Plot Validation Level
(2) classification plot: sufficient for inclusion in a classification revision
Overall Plot Vegetation Fields:
Field Height
5
m
Field Cover
20
%
Nonvascular Cover
50
%
Misc Fields:
Observation Narrative
An impressive but very disturbed "flatrock" of Triassic diabase, located on a small hill or knob by Elklick Run in the Culpeper Basin of Fairfax County. The west end of the outcrop was quarried long ago; although the main portion remained unaltered, it must have been heavily impacted by equipment and trampling during the quarrying operation. Later this area was used for grazing livestock, which had unrestricted access to the flatrock. As a result, this habitat has probably lost much of its native perennial flora, and now supports a weedy mix of mostly annual natives and exotics. Some characteristic plants of mafic barrens are present (e.g., Polygonum tenue, Isanthus brachiatus, Bulbostylis capillaris, Cyperus lupulinus, Krigia virginica) but others (e.g., Talinum teretifolium, Opuntia humifusa) are conspicuously absent. Plants are rooted in cracks, crevices, moss mats, and superficial mats of humus. No mineral soil could be located in this habitat.