PERMFILE42069

• Permit No: C1980003
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: Baseline Vegetation Inventory for the Proposed HG Mine
• Section_Exhibit Name: APPENDIX G
• Media Type: D
• Archive: No

but also has a limited distribution on the north slope in
the deep loams (Routt Series) as well as on the shallow
• gravelly loams (Delphill Series Complex) of ridgetops.
The sagebrush-snowberry community floristically is
the most diverse community at the study site. This is
due principally to the great number of grass and forbs
species present. Sixty-two species were identified in
the inventory: 6 shrubs, 40 forbs, 15 grasses and 1
sedge.
The shrub cover is generally dense, sometimes
covering 94 percent of the area. The shrub community is
dominated by three species: silver sagebrush, Artemisia
cana; big sagebrush; and snowberry. Snowberry is more
abundant than either of the sagebrush species, even when
their cover is considered accumulative. The dominance of
individual shrubs in this community is variable. Moist
areas on north slopes tend to be dominated by serviceberry,
with coverage as high as 82 percent. Sagebrush species
generally dominate drier sites, ridgetops, and southern
and western exposures. Silver sagebrush occurs in the
most mesic of these habitats, while big sagebrush dominates
the drier areas such as southwestern exposures. Occasionally,
both species of sagebrush occur together where both dry
and moist habitats exist. Other shrubs represented in
• the community include two species of rabbitbrush and
chokecherry.
Total percent herbaceous of vegetation cover averages
40 percent. In general, as the shrub density increases,
the total herbaceous vegetation cover decreases. Grasses
generally form the greater percent of the herbaceous
cover. Bluegrass, Poa agassizensis, the dominant herbacous
species, represents about one-fourth the total herbaceous
ground cover. Other dominant grasses in order of importance
include: mountain brome; giant wild-rye, which forms dense
clumps through the community; another bluegrass, Poa ampla;
slender wheatgrass, Agropyron trachycauZum; needlegrass,
Stipa ap.; and nodding brome.
Only nine of the forty forbs have an average cover
greater than one percent. Dominant forbs in order of
importance include: yarrow, sulfurflower, Eriogonum
umbeZlatum; milk vetch, AstragaZus sp.; aster; lupine,
Lupines wyethii; vetch; balsam-root, Balsamorhiza sp.;
giant-hyssop; and knotweed.
Litter and exposed soil are high in this community, covering
an average of 47 and 28 percent of the area, respectively.
Rocks, moss and lichens all have a low frequency and cover.
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