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3.1.1 Aspen Baseline Study Area <br />Review of Table V3 and Chart V1• indicates that the average vegetation cover of this aspen <br />community was 75.45%. Litter and rock provided an average of 19.97% and 0.0% of the ground cover, <br />respectively, while bare ground exposure averaged 4.59%. The dominant plant species were mountain <br />brome (Bromus marginatus), blue wildrye (Elymus glaucus), bluegrass (Poa agassizensis), mountain <br />snowberry (Symphoricarpos oreophilus), and nettleleaf giant hyssop (Agastache urticifolia) with 13.9%, <br />11.6%, 7.1%, 6.7% and 4.9% of the ground cover, respectively. Perennial plants (excluding noxious <br />weeds) contributed 96% of the total plant cover (72.52% average cover) while annual species and <br />noxious weeds contributed 4.0% and 0.6% of the composition, respectively. Perusal of Table V10 <br />indicates that a total of 7 perennial species contributed at least 3% relative cover or composition (30/o is <br />the typical lower limit for plant diversity bond release evaluations). Three of those species were grasses, <br />two were forbs, and the remaining two were shrubs. <br />Review of Tables V11 and Chart V3 indicates that the average herbaceous production of this area in <br />2005 was 1,249 pounds per acre, oven-dry weight. Ninety-eight percent (1,226 pounds per acre) of the <br />total herbaceous production is attributable to perennials, with grasses contributing 771 lbs./acre and <br />forbs providing 455 lbs./acre. One percent (12 pounds per acre) of the total production is attributable to <br />annuals (all forbs). Noxious weeds also contributed 1% or 11 pounds per acre to the average <br />herbaceous production. <br />Perusal of Tables V12 and Chart V4 indicates that the estimated woody plant density in this area <br />was 4,685 woody plants per acre. The shrub lifeform accounts for 93% of the total (4,346 plants per <br />acre) with sub-trees contributing 2% of the total (96 plants per acre) and the remaining 5% attributed to <br />trees (243 per acre). Mountain snowberry was the dominant woody species with 2,858 plants per acre <br />followed by chokecherry (Prunus virginiana) at 1,111 per acre. As indicated on Table V13, the density of <br />larger aspen averaged 139 trees per acre using the point-center-quarter method (the difference between <br />the two values was due to aspen recruitment - trees smaller than 5 feet that were not recorded in the <br />PCQ measurements). In addition, the canopy cover in the aspen community in the baseline study area <br />was visual estimated to average 31% (about one-half of normal expectancy). <br />The Aspen community appears to have been noticeably affected by the recent drought. A high <br />percentage of mature aspen trees have recently died leading to a lower live tree density and a dense <br />understory of chokecherry and mountain snowberry. The aspen stands in more mesic sites are healthy, <br />whereas stands that occupy or have expanded to more xeric sites have lost most of their mature <br />CIEDAR MIEKASSOC UTME.INC. Page 13 2005 Collom Vegetation Survey