2010-12-27_REVISION - C1981019 (3)

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3.0 RESULTS 3.1 Phase II Summary A total of 44 plant species were observed within the Phase II Bond Release area (all or part of 28 revegetated units) evaluated in 2007 (See Plates 1 & 2). These consisted of 23 grass taxa, 15 forbs, and 5 shrubs (see Table 3 in Appendix A). Table A -1 indicates all taxa observed during fieldwork. Among these taxa is the invasive weed cheatgrass (including Japanese brome), existing as notable patches. Ground cover in the Phase II Bond Release area (Table 1 and Chart 1) consisted of 66.0% live vegetation, 0.6% rock, 20.5% litter, and bare soil exposure of 12.9 %. Perennial cover across the unit averaged 56.3% (85.3% relative cover) with annual and biennial cover averaging 9.7% absolute cover (14.7% relative cover). Dominant taxa were thickspike wheatgrass (Agropyron dasystachyum), Kentucky bluegrass (Poa pratensis), and intermediate wheatgrass (Agropyron intermedium), with 11.4 %, 7.7 %, 5.9% average cover, respectively. Sub - dominant taxa were Japanese brome (Bromus japonicus), cicer milkvetch (Astragalus cicel), and crested wheatgrass (Agropyron cristatum) with 5.2 %, 4.8% and 4.7% average cover, respectively. With regard to diversity, the Phase II Bond Release Area exhibited 8 perennial grasses and 1 perennial forb with between 3% and 50% relative cover. 3.2 Reference Areas 3.2.1 Mountain Shrub Reference Area The Mountain Shrub Reference Area is comprised of approximately 18 acres of gently to moderately sloping vegetation that has a predominately northwesterly aspect (mesic) and easterly aspect (xeric) (see Plate 3). The Mountain Shrub Reference Area was expanded in 2005 to include the east - facing slope of the ridge to provide representation from the xeric subtype of Mountain Shrub. The purpose of this inclusion is to provide a better representation of the distribution of Mountain Shrub communities located on and around Colowyo properties. The xeric exposure tends to exhibit more elevated herbaceous parameters given a modest reduction in the overstory. This reference area is located on a ridge west of the West Pit Area. A total of 35 plant taxa were observed in this reference area (see Table 3). Ground cover in the Mountain Shrub Reference Area (Table 1) consisted of 56.4% live vegetation, 0.7% rock, 33.6% litter, and bare soil exposure of 9.4 %. Perennial cover across the unit averaged 51.4% with annual and biennial cover averaging 5.0 %. Dominant taxa were Mountain big sagebrush, bluegrass (Poa agasizensis), slender wheatgrass, Nelson's needlegrass (Stipa nelsonii), and cheatgrass with 11.3 %, 7.8 %, 6.3 %, 5.4 %, and 4.6% average cover, respectively. With regard to diversity, the Mountain Shrub CEDAR CREEK ASSOCIATES, Inc. Page 9 Colowyo Coal Company 2007 Phase II Evaluation (Updated Dec -10)