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
29
m
Shrub Height
5.5
m
Field Height
5
m
Tree Cover
75
%
Shrub Cover
20
%
Field Cover
70
%
Nonvascular Cover
4
%
Misc Fields:
Observation Narrative
Along with plots GFNP054 and GFNP056, this plot was sampled to explore the relationship between vegetation just above Great Falls on the Virginia side of the Potomac River with enigmatic vegetation documented by Chris Lea at a similar topographic position on the Maryland side. The three plots capture a habitat and vegetation gradient, from the upstream end of an "island" formed by the river, an old canal, and Mine Run to the downstream end just above the falls. The topography in this area transitions from a well-drained floodplain to the bedrock terrace that develops as the river drops precipitously through the falls. The floodplain in this plot is rocky and clearly beginning to transition to the bedrock terrace. The sample area contains irregular microtopography of cobbley channels which carry infrequent flood waters, but much of the vegetation resembles an oak-hickory forest. The site was flood-scoured during late June or early July of 2006.
0 - 10 cm: fine reddish-yellow sand
Composite sample collected from three locations.
Disturbance Data:
Disturbance Type
Disturbance Intensity
Disturbance Comment
unknown
Although exotics have significant cover in this plot, they are much worse in adjacent parts of the stand. The plot is adjacent to an old canal dug by George Washington to bypass the falls.