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
38
m
Shrub Height
6
m
Field Height
8
m
Tree Cover
80
%
Shrub Cover
20
%
Field Cover
50
%
Misc Fields:
Observation Narrative
Resample of 11-year old permanent plot. A deer exclosure was constructed around the quadrat a short time before the resampling was conducted. Conditions have changed considerably since 2001. Two blowdowns have created slight light gaps and tip-up mound soil disturbances that have led to the establishment of the exotic vines Rubus phoenocolasius and Celastrus orbiculatus. However, it is remarkable that only three exotics occur in the plot, all at low cover (only one occurred in 2001). The most obvious change is in the herbaceous flora, which has lower overall cover and differs from the 2001 sample in the relative abundance of some species. In 2001, Adiantum pedatum (25-50% cover), Actaea racemosa, and Oxalis violacea (both 10-25% cover) had the highest herbaceous cover. In 2012, these species had been reduced to 5-10%, 1-2%, and 0% (absent), while the unpalatable species Amphicarpaea bracteata (<1% in 2001) and Athyrium asplenioides (2-5% in 2001) had increased to 10-25% and 5-10% respectively. The only possible explanation for such pronounced changes is a dramatic increase in deer herbivory and selective grazing pressure, which has been evident over the entire northern Virginia region in the last decade.
See chemistry and profile data of original plot BULL007P.
Disturbance Data:
Disturbance Type
Disturbance Intensity
Disturbance Comment
unknown
Two large blow-downs, including the big Quercus rubra, since 2001. Two small snags (Liriodendron and Quercus alba) present in plot. The herb layer is less lush than in 2001, presumably because of heavy deer herbivory.
