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
24
m
Shrub Height
6
m
Field Height
5
m
Tree Cover
80
%
Shrub Cover
20
%
Field Cover
40
%
Nonvascular Cover
1
%
Misc Fields:
Observation Narrative
Plot is situated on a steep, north-facing slope above a very steep dolomitic limestone bluff subtending the North Fork Shenandoah River at the lower end of Brocks Gap. Despite the limestone substrate, soils here are only moderately calcareous, perhaps because of a local chert layer or because of leaching on the convex brow of the bluff. This site supports an exceptionally large stand of medium-age mixed forest with Thuja occidentalis the leading overstory and understory dominant throughout. The portion sampled by this plot has Pinus strobus and Fraxinus americana as the main associates of Thuja, with occasional Liriodendron tulipifera present and some Tsuga canadensis and other hardwoods in the understory. The herb layer is fairly diverse with a variety of nutrient-demanding forbs and sedges. Upslope, the stand abruptly transitions to an area that was once cleared for pastures and now supports nearly pure, small-diameter Thuja with a nearly continuous ground layer of dense Carex eburnea.