2010-12-17_REVISION - C1981019 (160)

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observed in the study area. Plates V17 through V21 provide photographic documentation of this community in the study area, as well as the reference area, at the time of sampling. 3.5.1 Mountain Shrub Baseline Study Area Review of Table V7 and Chart V1 indicates that the average vegetation cover of the Mountain Shrub community was 66.15%. Litter and rock provided an average of 23.0% and 1.7% of the ground cover, respectively, while bare ground exposure averaged 9.2%. The dominant plant species were mountain snowberry, bluegrass, and Gambel oak (Quercus gambelii) with 17.9%, 8.5% and 4.9% of the ground cover, respectively. Perennial plants (excluding noxious weeds) contributed 88% of the total plant cover (58.2% average cover) while annual species and noxious weeds contributed 12% and 0.3% of the composition, respectively. Perusal of Table V10 indicates that a total of 7 perennial species contributed at least 3% relative cover or composition (3% is the typical lower limit for plant diversity bond release evaluations). One of those species was a grass, one was a forb, and five were shrubs. Review of Tables V11 and Chart V3 indicates that the average herbaceous production of this area in 2005 was 927 pounds per acre, oven-dry weight. Eighty-eight percent (820 pounds per acre) of the total 41 herbaceous production is attributable to perennials, with grasses contributing 562 lbs./acre and forbs providing 258 lbs./acre. Eleven percent (105 pounds per acre) of the total production is attributable to annuals, with grasses contributing 86 lbs./acre and forbs providing 19 lbs./acre. Noxious weeds contributed 0.3% or 2.6 pounds per acre to the average herbaceous production. Perusal of Tables V12 and Chart V4 indicates that the estimated woody plant density in this area was 8,758 woody plants per acre. The shrub lifeform accounts for 83% of the total (7,305 plants per acre) with sub-trees contributing the remaining 17% of the total (1,453 plants per acre). Mountain snowberry was the dominant woody species with 5,083 plants per acre followed by Gambel oak, chokecherry, serviceberry (Amelanchier alnifolia), and mountain big sagebrush at 1,351, 694, 530, and 519 plants per acre, respectively. The mesic sub-type within this community is generally found on the steeper slopes with northerly aspects, while the xeric sub-type is found on the relatively flat uplands intergrading with mesic sagebrush as well intergrading with xeric sagebrush on the steeper slopes with southerly aspects. Gambel oak and chokecherry is more predominate in the mesic sub-type, while serviceberry appears to be more dominate in the xeric sub-type. On average, the mesic sub-type contains more grasses, forbs and less bare ground. Small islands of mountain and Wyoming big sagebrush are also more common in the xeric sub- CEDAR CREEK ASSOCU ES, INC. Page 26 2005 Collom Vegetation Survey