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The Sagebrush type is the most extensive type on the permit area, occupying approximately f• <br />707.5 acres (52 percent of the area). It is characteristically found on lower slopes and <br />exposed ridgetops that have predominantly west, northwest, or southwest aspects (Exhibit <br />10-1, Figures 10-5, and 10-6). Species composition was variable and included stands <br />dominated by mountain big sagebrush and alkali sagebrush, basin big sagebrush, and <br />mountain snowberry. The herbaceous unde rs to ry was also variable. Shrubs ranged in height <br />from 2 to 4 feet (.6 to 1.2 m). Several inclusions of chokecherry-se rv iceberry occurred <br />in the type, as were several grass, sedge, or cattail meadows along Hubberson Gulch, Water <br />Trough Culch, and Dry Creek. In addition, there were small areas that were dominated <br />exclusively by mulesear (Wyethia amplexicaulis). The complex distribution, lack of <br />distinct boundaries associated with these variants, and the small area covered by these <br />types, however, made it impractical to map them as individual types. <br />Canopy cover and percent frequency data are presented in Table 10-3. Total plant cover <br />(shrubs and herbs) was 83.5 percent in the original reference area and 62.4 percent i n the <br />proposed mine area. Big sagebrush contributed about 40 percen t cover in both, while <br />snowberry contributed 27 percent i n the original reference area and 14 percent i n the <br />proposed mine area. Big sagebrush was more widespread (90 percent frequency) in the study • <br />area plots than the reference area plots (76 percent frequency); snowberry occurred in a <br />nearly equal number of plots on the study and reference areas. <br />Perennial forbs and grasses with the highest cover and frequency percentages in the <br />original reference area included bl ue bu nch wheatgrass, fowl bluegrass, and American vetch. <br />In the mine permit study area, fowl bluegrass and lupine showed the highest cover and <br />frequency among grasses and forbs. <br />Estimated average shrub density for the sagebrush vegetation type on the mine study area <br />2 <br />was 51.9 stems/SOm (4,203 stems/acre); reference area average density was estimated to be <br />64.0 stems/SOm2 (5,183 stems/acre). Snowberry was more common (higher density) and big <br />sagebrush less common on the reference area as compared [o mine study area samples (Tables <br />4-25 and 4-26). <br />Herbaceous production in the Sagebrush vegetation type shows [hat grami voids contributed <br />slightly more production than forbs. The single dominant species was again Aentuc4y <br />bluegrass which contributed about 37 percent of the total gra mi void production. Other • <br />species making up most of the remaining production were western wheatgrass (Anronvrnn <br />74 <br />