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Comparison of the calculated t-statistic (t*) for the two areas with the respective tabular tvalues <br />indicates that in each case t* is less than t. This results in the conclusion that the total vegetation <br />ground cover and production for the Bottomland baseline study area is comparable (equal) to the values <br />obtained from the Bottomland reference area. <br />3.3 Grassland Community <br />This community type comprises 816 acres (6.0%) of the vegetation study area as indicated on Map <br />V1. The grassland type is predominately an early-seral community found in the flat uplands where <br />natural and prescribed burns have removed the sagebrush or mountain shrub overstory vegetation and <br />the usually sub-dominant grasses have flourished. Occasional small patches of the grassland community <br />can be found along high elevation ridges and summit where thin soils and high winds have inhibited <br />shrub densities. As indicated on Table V1, a total of 93 plant species were documented from this <br />community type in the baseline study area and 26 taxa in the reference area. No sensitive species were <br />observed within this area, while the noxious weeds Canada thistle, musk thistle, whitetop, and bindweed <br />(Convo/vu/us arvensis) were observed in the study area. Plates V9 through V12 provide photographic <br />documentation of this community in the study area, as well as the reference area, at the time of <br />sampling. <br />3.3.1 Grassland Baseline Study Area <br />Review of Table V5 and Chart V1 indicates that the average vegetation cover of the Grassland <br />community was 58.19%. Litter and rock provided an average of 25.8% and 1.4% of the ground cover, <br />respectively, while bare ground exposure averaged 14.6%. The dominant plant species were western <br />wheatgrass, cheatgrass, Sandberg bluegrass, Japanese brome, and prairie pepperweed (Lepidium <br />densifiorum) with 15.2%, 12.3%, 6.4%, 5.9% and 2.5% of the ground cover, respectively. Perennial <br />plants (excluding noxious weeds) contributed 60% of the total plant cover (34.8% average cover) while <br />annual species and noxious weeds contributed 39.6% and 0.6% of the composition, respectively. <br />Perusal of Table V10 indicates that a total of 4 perennial species contributed at least 3% relative cover or <br />composition (3% is the typical lower limit for plant diversity bond release evaluations). All four of those <br />species were grasses. <br />Review of Tables V11 and Chart V3 indicates that the average herbaceous production of this area in <br />2005 was 1,008 pounds per acre, oven-dry weight. Seventy-four percent (742 pounds per acre) of the <br />total herbaceous production is attributable to perennials, with grasses contributing 670 lbs./acre and <br />forbs providing 54 lbs./acre. Twenty-five percent (252 pounds per acre) of the total production is <br />cCIEDAiR CMEEK.MMATZO, INC. Page 19 2005 Collom Vegetation Survey