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The xeric sub-type within this community is generally found on the steeper slopes (thin soils) with <br />southerly aspects intergrading with xeric mountain brush and juniper scrub. The mesic sub-type is found <br />on the relatively flat uplands (deeper soils) intergrading with xeric mountain shrub, as well intergrading <br />with mesic mountain shrub on the steeper slopes with northerly aspects. As one would expect, the xeric <br />sub-type exhibits lower total vegetation cover (57% vs. 43%), lower vegetation. cover in each of the <br />lifeforms, and higher cover attributed bare ground and rock when compared with the mesic sub-type. <br />The mesic sub-type is dominated by mountain big sagebrush while Wyoming big sagebrush tends to <br />dominate the xeric sites. With regard to grasses, western wheatgrass and several bluegrasses are most <br />numerous in the mesic sites and Griffith's wheatgrass is dominant in the xeric sub-type. <br />A majority of the sagebrush community found within the study area is overly mature, dense, and <br />decadent. Land managers (Colowyo) have made several attempts to reduce the density of sagebrush as <br />well as created pockets of grassland and young stands of sagebrush. Evidence of sagebrush chaining <br />over approximately 60 acres was observed and it appears that over the past ten to fifteen years, <br />prescribed burns in large areas of sagebrush have been undertaken. In the higher elevations, most of <br />these burn areas have already seen sagebrush return and young, healthy sagebrush dominate the <br />clearings. At lower elevations with somewhat drier conditions the return of sagebrush to dominance <br />appears to be much slower and seral shrubs species such as snakeweed and low rabbitbrush, as well as <br />grasses, are still dominant. <br />3.6.2 Sagebrush Reference Area <br />Review of Table V8 and Chart V1 indicates that the average vegetation cover of the Sagebrush <br />reference area was 51.0%. Litter and rock provided an average of 32.8% and 0.7% of the ground <br />cover, respectively, while bare ground exposure averaged 15.6%. The dominant plant species were <br />Japanese brome, mountain big sagebrush, western wheatgrass, Sandberg bluegrass and snakeweed <br />(Guttierezia sarothrae) with 9.8%, 8.7%, 8.2%, 7.7% and 4.6% of the ground cover, respectively. <br />Perennial plants (excluding noxious weeds) contributed 75% of the total plant cover (38.3% average <br />cover) while annual species and noxious weeds contributed 25% and 0% of the composition, <br />respectively. Perusal of Table V10 indicates that a total of 6 perennial species contributed at least 3% <br />relative cover or composition (3% is the typical lower limit for plant diversity bond release evaluations). <br />Three of those species were grasses and the remaining three were shrubs. <br />Review of Tables V11 and Chart V3 indicates that the average herbaceous production of this area in <br />2005 was 907 pounds per acre, oven-dry weight. Eighty-two percent (741 pounds per acre) of the total <br />CMDDAM CREI A2MOA S, INC. Page 30 2005 Collom Vegetation Survey