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• Within the surface disturbance area, seven vegetation types were delineated (Alkali Sagebrush / <br />Western Wheatgrass, Aspen, Improved Pasture / CRP, Mixed Conifer, Mesic Drainage / Riparian, <br />Mountain Brush, and Sagebrush) of which three (Sagebrush, Mountain Brush, and Improved <br />Pasture / CRP) accounted for 96% of the area. These latter three were deemed to be the major <br />types for which detailed quantitative sampling would be appropriate. All but Mined and <br />Reclaimed Land were documented from 2008 sampling; Mined and Reclaimed Land <br />documentation was fully accomplished in 2006 as part of bond release testing and those <br />quantitative data are used here. <br />Vegetation Descriptions — Quantitatively Sampled Types <br />IMPROVED PASTURE / CRP LANDS <br />Photographs 21 through 30 (Quantitative Study Area), Photographs 42 and 43 (General Study <br />Area) <br />This vegetation is present in areas that were likely cultivated for the production of small grains but <br />later were converted to grasslands through planting of domesticated grasses, mostly intermediate <br />wheatgrass (Thinopyrum intermedium) and smooth brome (Bromopsis inermis). The conversion <br />• of some of these lands occurred under provisions of the U.S. Department of Agriculture <br />sponsored "Conservation Reserve Program" (CRP) that encourages stabilization of marginal <br />cropland through planting of perennial grasses and other plants that would control erosion on <br />these often highly erodible fields. The areas of CRP land in the area are apparently planted to a <br />relatively simple mix of exotic grasses. This vegetation unit is found on sites that were formerly <br />occupied by Sagebrush or Mountain Brush vegetation types. <br />Within the quantitative study area in 2008, these domesticated forage grasses account for 77.5 <br />percent of total vegetation cover (Table 5). The major two contributors to this are smooth brome <br />and intermediate wheatgrass. Some native perennial cool season grasses are also present <br />including Agassiz bluegrass (Poa agassizensis) as well as a few native and introduced annual <br />and biennial forbs which each accounted for 2.4 percent of vegetation cover. A total of twenty - <br />four species of native perennial forbs were observed in the affected area samples. <br />Total vegetation cover in the affected Improved Pasture vegetation type was 43.8 percent (Table <br />5), while standing dead, litter, bare soil, and rock 1.1, 32.3, 22.7 and 0.1 percents, respectively. <br />By comparison, in the Improved Pasture Reference Area, total vegetation cover was 43.0 percent <br />(Table 15), while standing dead, litter, bare soil, and rock 1.9, 34.7, 20.3 and 0.1 percents, <br />0 12 <br />