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<br />Daub & Associates, Inc. Page 3-50 2015 NS Mine Plan Modification <br />1/5/2016 Section 3 General Site Conditions <br />Big Sagebrush Shrubland <br />The Big Sagebrush Shrubland type is a shrub dominated community found in <br />drainages and gentle slopes usually on Yamac or Piceance fine sandy loams. The <br />type is generally characterized by a shrub overstory of big sagebrush (Artemisia <br />tridentata), ranging from 42 to 6 percent cover with an average of 25.6 percent cover <br />(Table 3-12). Lesser amounts of winterfat (Ceratoides lanata), rubber and Douglas <br />rabbitbrush (Chrysothamnus nauseosus and c. viscidiflorus), and snakeweed <br />(Guiterrezia sarothrae) are also found; these species never comprised more than six <br />percent of the shrub cover. Total shrub cover ranged from 46 to 8 percent with an <br />average of 31 percent. <br />Forbs were uncommon in the Big Sagebrush type, comprising 4.6 percent of the <br />total cover. Common forbs included: northern sweetvetch (Hedysarum boreale); <br />hood phlox (Phlox hoodii), scarlet globemallow (Sphaeralcea coccinea), narrow- <br />leaved aster (Machaeranthera linearis), silvery lupine (Lupinus argenteus), and <br />Wyoming painted-cup (Castilleja linariaefolia). In disturbed areas, weedy species <br />such as pinnate tansy mustard (Descurinia pinnata), tumble mustard (Sisymbrium <br />altissimum), Russian thistle (Salsola kali), and yellow sweetclover (Melilotus <br />officinalis) are commonly found. Grasses are an important component of this type <br />comprising 26 percent of the cover. Dominance varied between sample sites but <br />generally prairie junegrass (Koeleria macrantha) is the most important species, with <br />western and bluebunch wheatgrass (Agropyron smithii and A. spicatum), also being <br />found. However, in some areas, possibly due to grazing related disturbance <br />cheatgrass (Bromus tectorum) and needle-and-threadgrass were the dominant <br />species. Also important were Sandberg bluegrass (Poa secunda) and Indian <br />ricegrass (Oryzopsis hymenoides). <br />Saline soils are found in a few swales and other areas, which are dominated by <br />black greasewood (Sarcobatus vermiculatus), big sagebrush, and scattered <br />shadscale (Atriplex confertifolia) shrubs, comprising about 28 percent cover (Table <br />3-12; transect SB-2). Forbs were poorly represented, although grasses, especially