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1 <br /> <br /> <br />1 <br />1 <br />1 <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />1 <br /> <br /> <br />Sampling Results <br />Total vegetation cover in the sagebrush community averaged 26.3X with <br />grasses, forbs, and shrubs contributing 6.gX, 8.4X, and 84.7X, respectively <br />(see Table 1). Four samples were needed to attain sample adequacy at an SOX <br />confidence level; ten samples were taken. <br />As is evident from the data, the sagebrush community has been heavily <br />Impacted in the past by grazing activities. Two shrub species, biq <br />sagebrush (Artemisia tridentata) and shadscale (Atriplex confertifolia) <br />dominate the community, with 84.5X relative cover. The remaining vegetative <br />cover is derived primarily from annual forbs, such as alyssum (Alyssum <br />desertorum) and pinnate tansymustard (Descurainia ip'nnata), and cheatgrass <br />(Bromus tectorum), There are few herbaceous perennials and these occur <br />infrequently. Consequently species diversity, as measured by the <br />Shannon-Wiener index, is extremely low (H' = 0.40). Only four species -- <br />big sagebrush, shadscale, cheatgrass, and alyssum -- exceed 1X relative <br />cover (see Table 2). <br />Cover and Diversity Standards <br />The revegetation success standard for cover has been obtained from the <br />baseline survey conducted in 1983, ,~e~i,at:ive.•CdY•er. eXtTu#iAg <br />ceni:#E~guSf~M6 #eem annuals and biennials was-estimated to be approximately <br />23X...7he value of 23X will therefore be used as the cover standard on <br />re4laimed areas., <br />Since there were four species with relative cover values exceeding 3X, <br />the proposed diversity standard will also be four species, with relative <br />cover values exceeding 1X. These four species will contain at least two <br />different life forms (i.e., grass, forb, or shrub). This standard is <br />proposed in light of the history of mining-related disturbance in the area <br />of Lhe mine site and of the present lack of diversity in the sagebrush <br />community. <br /> <br />