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
25
m
Shrub Height
4
m
Field Height
5
m
Tree Cover
90
%
Shrub Cover
30
%
Field Cover
10
%
Nonvascular Cover
35
%
Misc Fields:
Observation Narrative
Plot captures a convex, north-facing talus slope bordering the Potomac River floodplain. There are many downfalls on this unstable slope, which is covered with fine, flat fragments of metagrawacke. The extremely rocky substrate limits herbaceous cover, vigor, and diversity. Soils collected from this site have very high calcium content, equivalent to that of soils weathered from limestone. This cannot be explained by the mapped geological unit (Mather Gorge metagrawacke), a rather acidic rock, and may be the result of undetected intrusive bodies of mafic material.