standing dead, litter, bare soil, and rock were 0.4, 10.8, 6.0, and 0.5 percents, respectively.
<br />• Species density in the Mountain Brush effected areas was 37.5 species per 100 sq. m., while
<br />in the extended reference areas, it was 36.1 species per 100 sq. m.
<br />Herbaceous biomass production averaged 785 pounds oven-dry per acre in the affected area
<br />(Appendix 108, Table 10B-31 and 814 pounds oven-dry per acre in the extended reference area
<br />iAppendix tOB, Table 10B-4). Similar to the understory of aspen areas, the herbaceous
<br />biomass production of the mountain brush sites is limited by shading and other forms of
<br />competition with the extensive woody cover, so even under favorable moisture conditions,
<br />moderate herbaceous biomass production, as identified, would be expected.
<br />Shrub density in the Mountain Brush vegetation type affected area averaged 14,804 stems per
<br />acre (Appendix 108, Table tOB-51; slightly over half of this was mountain snowberry and most
<br />of the remainder was attributable to Saskatoon serviceberry, black chokecherry, and Gambel's
<br />oak. In the extended reference area, the average was 17,184 stems per acre (Appendix 108,
<br />Table lOB-61, with a very similar proportional species composition.
<br />Steep Mountain Brush Vegetation Type (Photos 17 through 241
<br />This vegetation unit is differentiated from the Mountain Brush unit by its occurrence on steeper
<br />• sites with generally shallower soils and generally lower moisture availability. It is dominated by
<br />native shrubs as is the Mountain Brush unit, but with less representation of black chokecherry
<br />and more representation of big sagebrush. Native perennial cool season grasses (Appendix
<br />10C, Table 10C-11 were much more abundant here than in. the Mountain Brush areas, and
<br />comprised 16.5 percent of total vegetation cover. The major contributing species here were
<br />western wheatgrass (Pascopvrum smithiil, Agassiz bluegrass, and bluebunch wheatgrass
<br />IPseudoroecneria spicatal. Other common species included elk sedge, mountain brome, slender
<br />wheatgrass, and Junegrass (KOeleria macranthal. Native perennial forbs accounted for a much
<br />smaller portion of total vegetation cover than in the Mountain Brush type, with only 7.9
<br />percent of total vegetation cover. Although fifty-one species were observed, only western
<br />yarrow, white-flowered peavine, and Canada goldenrod (So/idago canadensisl made substantial
<br />cover contributions. Other common species included tapertip onion IA//ium acuminatum),
<br />arrowleaf balsamroot (Balsamorhiza sagittetal, northern bedstraw lGalium septentrionalel,
<br />tailcup lupine ILupinus caudaius/, microseris (Microseris nutansl, longleaf phlox (Ph/ox
<br />lon.oifo/ial, lambstongue groundsel ISenecio intaerrimus), American vetch, and violet (Vio/a
<br />praemorsal. Introduced annual grasses made up a minor portion (t.6 percent) of vegetation
<br />cover. Species present included both cheatgrass (Anisantha tectorum/ and Japanese brome
<br />(Bromus japonicusl. Common native annual and biennial forbs present included linearleai
<br />collomia and bigfruit willowherb (Epi/obium brachVCarpum/.
<br />I
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