Definitions Used Throughout the Site
From the Community Summary Slides:
NOVA Plots: DCR-DNH plots that were selected from the statewide DCR-DNH plots to create the fine filter views of Natural Communities in Northern Virginia
Statewide Plots: The full set of plots collected by the DCR-DNH and available on their website
Mean Species Richness per 1/10 acre: This is the average of the number of species which were found in each plot in the DCR-DNH data. It gives a relative sense of the richness of the species found in any one area. The plots were mostly 400 square meters, which translates almost exactly into 1/10 acre.
Total # species: This is the total number of species which are found in the plots for Northern Virginia, also a measure of the richness of the species diversity found in Northern Virginia plots.
Comments at the bottom of the slides that list the Dominant, Common, Sparse, and Restricted Species:
A: (ARMN) Not documented as native in Arlington County or City of Alexandria: For work in Arlington County, do not add species if they are marked with an “A”
B: Species found in widely differing amounts throughout a forest: Lots of natural variation in the quantity of these species is expected. This measure was created by aggregating NOVA plots into 4 categories of cover when the species was present—Up to 1%, 1-5%, 5-25%, and over 25%. The plot count was converted to percentages by category and the maximum was defined. High variability was defined as the Maximum Percentage less than 45%.
C: Generally not recommended to add due to overabundance: These species are generally now over-represented as they are not favored species by deer. Generally no need to add more.
D: Species likely under-represented now due to invasive pathogens or insects: Observers are likely to find these species under-represented in communities, sometimes making community identification more difficult. Note that while harmed by invasive pathogens, Flowering Dogwoods are still encouraged to be planted in Arlington County. However Green Ash, White Ash, and Eastern Hemlock are not recommended to be planted due to likely not surviving given current conditions with the Emerald Ash Borer and the Woody Adelgid.
E: Species likely under-represented now due to deer browse: This is a highly limited list, primarily focused on shrubs and trees that are highly desired by hungry deer. The actual list could be much longer depending on the intensity of deer browse.