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thimbleber ry (Rubus pa rviflorus), which was rare in the affected area, had even slightly • <br />greater density than mountain snowberry. The major subordinate shrubs in terms of density <br />in both the affected and reference areas were Saskatoon serviceberry and black chokecherry <br />(Prunus vi rginiana var. melanocarpa). <br />In the Aspen Woodland vegetation type, slightly less than half the total herbaceous <br />production was provided by graminoids, most abundant of which was Kentucky bluegrass and <br />blue wildrye. The only other graminoids with significant production were elk sedge (Ca rex <br />geyeri) and mountain brome (Gera tochloa marginata). Of the forbs, perennial native forbs <br />were by far the most productive. Dominant among these were western yarrow, western <br />tickweed (Hackelia floribunda), mountain bluebells, spreading sweetroot, and violets <br />(Viola spp.). <br />Mixed Brush. Tables 3-15 and 3-16 in Appendix 10-3 list cover data collected in the Mixed <br />Brush vegetation type from the mine site and original reference area. Tables 3-19 and <br />3-20 include shrub density height data and Tables 3-17~and 3-18 present the herbaceous <br />production. This vegetation type is the second most extensive type on the mine study <br />area, occupying approximately 587 acres (43 percent of the area). Stands of mixed brush • <br />occupy west-, north-, northwest-, and southwest-facing slopes and gullies (Exhibit 10-1, <br />Figures 10-3 and 10-4 ). These thickets may be quite dense, ranging from 80 percent brush <br />cover along gully bottoms, to scattered, with about 30 percent brush cover in drier upland <br />sites. <br />Average combined shrub and herb cover was 98.8 and 86.2 percent for the mine and reference <br />areas respectively (Table 10-3). Snowberry occurred in nearly all quadrats sampled, <br />providing more cover than any other species (45 percent in the reference area, 38 percent <br />in the mine area). Cambel oak ryas the tallest over story species and contributed the <br />highest canopy cover and frequency percentages of any shrub species except snowberry in <br />both mine and reference areas. Gambel oak and chokecherry were most abundant on moist <br />sites, mainly north- and east facing slopes, while serviceberry, although abundant in <br />moist sites, also conononly occurred in isolated patches on dry slopes. In wetter areas, <br />two brush strata were apparent, the lower composed primarily of snowberry about 3 feet (1 <br />m) in height, and the uper composed of Cambel oak and chokecherry 10 to 15 feet (3 to 5 m) <br />in height. On drier sites, one stratum composed of mountain snowberry and mountain big <br />sagebrush (Artemisia tride nt ata ss p. vaseyana) 2 to 3 feet (.6 to 1 m) in height was • <br />present. <br />20 <br />