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A total of 35 plant taxa were observed in this reference area evaluated in 2008 (see Table A-1). <br />Current annual herbaceous production across the area averaged 584.6 pounds per acre in 2008 with <br />perennial grasses the dominant category (see Table 3). Ground cover in the Mountain Shrub Reference <br />Area (Table 1) consisted of 63.0% live vegetation, 0.5% rock, 31.3% litter, and bare soil exposure of <br />5.2%. Perennial cover across the unit averaged 55.1% with annual and biennial cover averaging 7.8% <br />and noxious weed cover with 0.1%. Dominant taxa were big sagebrush, mountain snowberry, <br />cheatgrass, bluegrass (Poa agasizensis), and Letterman's needlegrass (Stipa iettermanii), with 12.3%, <br />6.6%, 6.2%, 4.9%, and 4.7% average cover, respectively. With regard to diversity, the Mountain Shrub <br />Reference Area exhibited 6 perennial grasses and 1 perennial forb with between 3% and 50% relative <br />cover. Total relative cover for all perennial forbs in the Mountain Shrub reference area was 12.2%. <br />3.2.2 Sagebrush Reference Area <br />The Sagebrush Reference Area is comprised of approximately 4.7 acres of gently to moderately <br />sloping vegetation that has a predominately northerly aspect (see Plates 7 and 8). This reference area is <br />located on a gently sloping ridge north of the Administration / Facilities Area (see Maps 5 and 6). <br />A total of 45 plant taxa were observed in this reference area evaluated in 2007 (see Table A-1). <br />Current annual herbaceous production across the area averaged 588.1 pounds per acre in 2007 with <br />perennial grasses the dominant category (see Table 3). Ground cover in the Sagebrush Reference Area <br />(Table 1) consisted of 57.3% live vegetation, 3.0% rock, 29.0% litter, and bare soil exposure of 10.8%. <br />Perennial cover across the unit averaged 42.0% with annual and biennial cover averaging 15.3%. <br />Dominant taxa were Japanese brome, Mountain big sagebrush, Sandberg's bluegrass (Poa secunda), <br />western wheatgrass, and prairie junegrass (Koeieria macrantha) with 10.5%, 10.0%, 6.0%, 4.7%, and <br />2.9% average cover, respectively. With regard to diversity, the Sagebrush Reference Area exhibited 5 <br />perennial grasses and 1 perennial forb with between 3% and 50% relative cover. Total relative cover for <br />all perennial forbs in the Sagebrush reference area was 8.1%. <br />A total of 30 plant taxa were observed in this reference area evaluated in 2008 (see Table A-1). <br />Current annual herbaceous production across the area averaged 608.2 pounds per acre in 2008 with <br />perennial grasses and annual grasses the dominant categories (see Table 3). Ground cover in the <br />Sagebrush Reference Area (Table 1) consisted of 57.9% live vegetation, 2.4% rock, 25.6% litter, and <br />bare soil exposure of 14.2%. Perennial cover across the unit averaged 34.7% with annual and biennial <br />cover averaging 22.8% and noxious weed cover with 0.1%. Dominant taxa were cheatgrass, big <br />sagebrush, Japanese brome, prairie junegrass (Koeieria macrantha), and western wheatgrass, with <br />CEDAR CREEK ASSOCIATES, Inc. Page 11 Colowyo Coal Company <br />2008 Phase III Bond Release Evaluation