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
200
m²
Plot Quality Fields:
Plot Validation Level
(2) classification plot: sufficient for inclusion in a classification revision
Overall Plot Vegetation Fields:
Tree Height
7
m
Shrub Height
5
m
Field Height
5
m
Tree Cover
3
%
Shrub Cover
20
%
Field Cover
85
%
Nonvascular Cover
3
%
Misc Fields:
Observation Narrative
This plot documents the only known Shenandoah Valley sinkhole pond in Rockbridge County (most are in Augusta and Rockingham counties to the north). It is a relatively small pond that is seasonally flooded to a maximum depth of 75 cm near the center. The plot is located in the western half of the pond, which floods to depths of 25 to 55 cm as measured by water marks on trees. On the sampling date, the pond was covered by a dense growth of Panicum rigidulum var. rigidulum, with scattered associates of Panicum dichotomiflorum, Paspalum laeve, Viola lanceolata, and Phyllanthus caroliniensis. A few additional low-cover herbs were confined to organic mats on the rim of the pond. An open stand of 4 to 6m tall Diospyros virginiana occupies about half the plot, giving it the appearance of a short "savanna." Despite its proximity to a highway, old Forest Service roads, and adjacent past clearcuts, this wetland appears surprisingly undisturbed.
