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cover). Dominant taxa were big sagebrush (Artemisia tridentata), mountain snowberry (Symphoricarpos <br />oreophi/us), cheatgrass, bluegrass (Poa agasizensis), and Letterman's needlegrass (Stipa /ettermanii), <br />with 12.3%, 6.6%, 6.2%, 4.9%, and 4.7% average cover, respectively. With regard to diversity, the <br />Mountain Shrub Reference Area exhibited six perennial grasses with between 3% and 50% relative cover <br />(Table 2). Total relative cover for all (orbs excluding noxious weeds in the Mountain Shrub reference <br />r- 'I <br />LJ <br />• <br />Ah <br />area was 14.8%. <br />A total of 28 plant taxa were observed in this reference area (Table Al). Current annual herbaceous <br />production across the area averaged 630.0 pounds per acre in 2009 with perennial grasses the dominant <br />category (Table 3). Ground cover in the Mountain Shrub Reference Area (Table 1 and Chart 1) consisted <br />of 61.3% live vegetation, 0.7% rock, 33.2% litter, and bare soil exposure of 4.9%. Perennial cover <br />across the unit averaged 54.7% (89.2% relative cover) with annual and biennial cover averaging 6.7% <br />(10.8% relative cover). Dominant taxa were big sagebrush, bluegrass, mountain snowberry, and slender <br />wheatgrass (Agropyron trachycau/um), with 10.6%, 8.6%, 7.5%, and 6.3% average cover, respectively. <br />With regard to diversity, the Mountain Shrub Reference Area exhibited five perennial grasses with <br />between 3% and 50% relative cover (Table 2). Total relative cover for all forbs excluding noxious weeds <br />in the Mountain Shrub reference area was 9.1%. <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. Plates 7 and 8 show site conditions <br />observed in 2008 and 2009, respectively. This reference area is located on a gently sloping ridge north <br />of the Administration / Facilities Area (Maps 5 and 6). Current annual herbaceous production across the <br />area averaged 608.2 pounds per acre in 2008 with the dominant categories being perennial grasses and <br />annual grasses (Table 3). Ground cover in the Sagebrush Reference Area (Table 1 and Chart 1) <br />consisted of 57.9% live vegetation, 2.4% rock, 25.6% litter, and bare soil exposure of 14.2%. Perennial <br />cover across the unit averaged 34.7% (60% relative cover) with annual and biennial cover averaging <br />23.2% (40% relative cover). Dominant taxa were cheatgrass, big sagebrush, Japanese brome (Bromus <br />japonicas), prairie junegrass (Koeieria macrantha), and western wheatgrass, with 14.1%, 9.6%, 8.0%, <br />4.9%, and 4.3% average cover, respectively. With regard to diversity, the Sagebrush Reference Area <br />exhibited four perennial grasses with between 3% and 50% relative cover (Table 2). Total relative cover <br />for all forbs excluding noxious weeds in the Sagebrush Reference Area was 6.9%. <br />CEDAR CREEK ASSOCIATES, Inc. Page it <br />'qW <br />lm1W <br />Colowyo Coal Company <br />2009 Phase III Bond Release Evaluation