2011-03-24_REPORT - C1981019 (10)

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2.2 East Pit 2.2.1 EP036 EP036 is comprised of 68.3 acres of gently sloping revegetation that has predominately east aspects. This unit was seeded in 2000, making 2010 the tenth growing season. A total of 39 plant taxa were observed in the unit (Table AB-1). Current annual production across the unit averaged 2,551.3 pounds per acre in 2010 with perennial grasses and perennial forbs the dominant categories (Compendium 1). Ground cover in EP036 consisted of 57.0% live vegetation, 1.0% rock, 32.1% litter, and bare soil exposure of 10.0%. Perennial cover across the unit averaged 50.6%. Dominant taxa"" were thickspike wheatgrass (Agropyron a ., dasystachyum), cicer milkvetch (Astraga/us cicet), and basin wildrye (Elymus cinereus) with 13.3%, 8.2%, and 5.3%, respectively. Sub-dominant taxa include Siberian wheatgrass (Agropyron sibericum), ° streambank wheatgrass (Agropyron riparium), and $ alfalfa (Medicago sativa) with 4.7%, 4.7%, and 2.8% 1 ' average cover, respectively. Woody plant density LvlewmMh?e?Re?+ai?ra,nd ii e?s?so+ x 41 was determined from 20 belt transects. Density EPQ36 (Table 3) totaled 941 young and mature stems per acre with big sagebrush (Artemisia tridentata) the dominant woody plant. With regard to diversity, EP036 exhibited five perennial grasses with between 3% and 50% relative cover and relative forb cover of 25.0% (excluding noxious weeds). This unit readily passes cover and production bond release comparisons (Charts 1 and 2). Unit EP036 also passes the diversity standard of two perennial grasses with between 3% and 50% relative cover and relative forb cover between 1% and 50% (Charts 3 and 4). This unit contains at least 33.7 acres of qualified shrub units that will contribute to the woody plant density standard of 150 stems per acre on 3% of the reclaimed land. Shrub patches were delineated using 300 stems per acre as a guideline. Therefore, actual acreage that meets the new standard will likely be higher. Noxious weed control efforts in this unit should be elevated given several scattered populations of Canada thistle (Cirsium arvense) observed intermittently throughout the unit. There are several small patches of annual bromes scattered throughout the unit, although these brome patches currently represent only 1.9% cover, down from 10.2% in 2007. Therefore, additional control is not needed. At present, EP036 passes all bond release criteria and is a good example of an improved pasture grassland community with a strong sagebrush component. This unit would contribute strongly to the local system given both cover and foraging habitat for wildlife (especially elk), as well as provide a variety of management opportunities for livestock grazing. Cedar Creek Associates, Inc. 12 COlowyo Mine 2010 Revegetation Monitoring Report