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• Average height for ell shrubs is 60 centimeters, ranging from <br />25 centimeters for fringed sage to 118 centimeters for skunkbrush. Average <br />height for big sagebrush is 54 centimeters, 57 centimeters for mountain <br />mahogany, end 35 centimeters for low rabbitbrush. <br />3.2.2 Rubber Rabbitbrush Shrubland <br />This community represents a successional stage of the big <br />sagebrush community type. A portion of the big sagebrush community of the <br />project site was plowed end planted with introduced hey grasses to create <br />pasturelands. These areas have not been maintained by the ranchers, and <br />colonizing species, such as rabbitbrush, have invaded and established the <br />present successional Rubber Rabbitbrush Shrubland community. As shown in <br />Figure 3.2.2-1, this community is itself being invaded by, and giving way <br />to, big sagebrush. <br />Cover <br />Twenty-seven species were identified in this vegetation type. <br />They include: 7 shrubs, 5 graminoids, 14 forbs, and 1 succulent. This <br />vegetation type i5 characterized by a relatively dense Shrub Stratum which <br />is visually dominated by rubber rabbitbrush. Total vegetation cover is <br />45.3 percent. This cover is composed of a 31.3 percent shrub cover, <br />• followed by a 12.0 percent graminoid cover end a 2.0 percent forb cover. <br />Litter cover is relatively high 133.0 percentl, soil cover is intermediate <br />119.0 percent), end rock cover is low 12.7 percentl. See Table 3.2.2-1. <br />Rubber rabbitbrush provides 25.7 percent cover or 57 percent of <br />the total vegetation cover. Other common shrubs ere fringed sage (3.0 per- <br />cent cover) and big sagebrush 12.3 percent coved . Broom snakeweed is <br />sparsely present. <br />Crested wheatgrass Agn.opy~can dv.~en#o2um, en introduced hey grass, <br />represents 94 percent of the graminoid cover and 25 percent of the total <br />vegetation cover. Minor graminoid components include cheatgrass end needle <br />and thread. Other grasses observed in the community include: smooth brome <br />and sand dropseed Spvaobo.lu.~ cf. ~~p#~~. <br />Fourteen forbs were present in the vegetation type. However, <br />only three species occurretl in cover transacts. They include scarlet globe- <br />mallow, golden aster, and alfalfa M¢di.ca¢n ~ativa. <br />Production <br />The estimated production of clipped plots ranges from 15.1 g/m2 <br />to 117.6 g/m2 end averages 51.7 g/m2 or 461 .pounds per acre. Graminoids <br />produce 50.5 g/m2 19B percentl of the total biomass. Forb production is <br />insignificant with 1.2 g/m2. Crested wheatgrass provides 49.7 g/m2 or 96 <br />• percent of the estimated total herbaceous biomass. See Table 3.2.2-2. <br />-11- <br />