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RULE 2 PERMITS <br /> Following is a general description of each of the vegetation communities, including various <br /> environmental factors contributing to the distribution of the types. The relationships between soil <br /> particle size versus soil moisture and their combined effect on vegetation community distribution <br /> is illustrated on Figure 2.04.10-1, Environmental Gradient/Plant Tolerance Graph. <br /> Sagebrush Community <br /> The sagebrush community is characterized by almost complete dominance of the overstory by big <br /> sagebrush(Artemisia tridentatel), and snowberry(Symphoricarpos oreophilus), at a density of <br /> 2,739 and 1,822 plants per acre, respectively. The measurement of snowberry density is a very <br /> subjective measurement whereby large clumps of the species make actual measurement of <br /> individual plants along the transect very difficult. Therefore,the given density value is, at best, an <br /> approximation of actual density but still provides an indication of relative abundance in the overall <br /> vegetative community. For additional woody plant density values by species refer to Table <br /> 2.04.10-6, Woody Plant Density. <br /> The growth form of the community is characterized by scattered shrubs of low to medium height, <br /> rarely exceeding four feet. Numerous areas of: open ground exist with various grasses and forbs <br /> comprising the understory. The most abundant grasses are western wheatgrass (Agropyron <br /> smithii),Kentucky Bluegrass(Poa pratensis),mountain brome(Bromus marginatus),and green <br /> needlegrass(Stipa viridula). The most abundant forbs are lupine(Lupinus caudatus),wild onion <br /> (Allium spp.), arrowleaf balsamroot (Balsamorhiza sagittata), and yarrow(Achillea lanulosa). <br /> During 1980 and 1989 the total herbaceous cover was determined to be 30.9% and 39.71% <br /> respectively. For details on cover of individual species refer to Table 2.04.10-2, 1980 Herbaceous <br /> Cover by Species and Table 2.04.10-3, 1988 Herbaceous Cover by Species. <br /> During 1980 and 1988, total herbaceous production for the sagebrush community was determined <br /> to be 436.1 and 825 pounds per acre respectively. According to these production figures, the <br /> carrying capacity in animal unit months (AUMs) , assuming 1,000 pounds of air dry forage per <br /> AUM at 50% utilization, would be from 0.22 to .41 AUMs per acre. Based on the determination <br /> by the Bureau of Land Management of an average production of 0.14 AUMs per acre for the <br /> sagebrush type in this area, it is evident that the condition of the sagebrush community with the <br /> permit area is good. Grazing has not occurred from the initial lease area since 1977. Grazing on <br /> the permit area addition should be discontinued in 1991 with the construction of wire livestock <br /> fencing. <br /> The sagebrush community is found throughout the permit area on all elevations, slopes and soils. <br /> On portions of the permit area where soil moisture retention and soil depth become limiting to the <br /> other vegetation communities,the sagebrush community develops. Snowberry will occur in greater <br /> numbers within the community where moisture retention is favorable. <br /> For further details on Soil/Moisture relationships in determining vegetation communities refer to <br /> Figure 2.04.10-1, Environmental Gradient/Plant Tolerance Graph. <br /> Rule 2 Permits 2.04-53 Revision Date: 12/20/19 <br /> Revision No.: TR-135 <br />