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Shrub density averaged 18,551 stems per acre (Table B25), mostly alkali sagebrush and <br />• greasewood. <br />The following discussion describes species dominance in the Alkali Sagebrush / Greasewood <br />vegetation type based on the all-laver relative cover values. All percentages given in the following <br />paragraph refer to this cover statistic. <br />Native shrubs were the most abundant lifeform with regard to cover, 53.8 percent of cover, about <br />9/10 of which was alkali sagebrush and 1/10 was greasewood (Sarcobatus vermiculatusl. Next <br />most abundant was native perennial grasses with 27.1 percent of cover, by far the largest part of <br />which was western wheatgrass, with much smaller amounts of Junegrass and Agassiz bluegrass. <br />Native perennial (orbs accounted for 7.5 percent of vegetation cover; major contributors to this <br />amount were western yarrow, groundsmoke (G~yophytum diffusuml, curlycup gumweed (Grindelia <br />8puar~osal, stemless goldenweed (Stenotus acaulisl, and meadow aster (Viroulus cam ep strisl. <br />Cover by introduced perennial (orbs, comprised of devil's shoesVings (Polygonum aviculare) and <br />common dandelion, amounted to 3.5 percent of cover. The only other lifeform with significant cover <br />was native annual and biennial fortis, with 5.5 percent of cover, all of the measurable part of which <br />• was Douglas knotweed. <br />Conservation Reserve Program (CRP) Land (figure 20) <br />Along the haul road corridor are located areas of land until recently cultivated for the production of <br />small grains. These lands have been placed in the U. S. Government-sponsored 'Conservation <br />Reserve Program' (CRP) that encourages stabilization of marginal cropland through planting of <br />perennial grasses and other plants that would control erosion on these often highly erodible fields. <br />The areas of CRP land examined here were apparently planted to a relatively simple mix of exotic <br />grasses, the most successful of which has been intermediate wheatgrass. Although the intermediate <br />wheatgrass has grown vigorously and produced cover approximately 5 feet in height in much of the <br />area, total vegetation cover was a moderate 44.8 percent (Table B11), with bare soil cover of 37.1 <br />percent and litter cover of 18.0 percent. Species density was very low, at only 3.8 species per <br />100 sq. m. Despite modest cover, the height of the intermediate wheatgrass contributed to a <br />relatively high herbaceous production of 3542 Ibs per acre (Table B16). <br />The folowing discussion describes species dominance in the CRP vegetation type based on the ;aIL- <br />• 1;i1CflLlelative cover values. All percentages given in the following paragraph refer to this cover <br />statistic. <br />19 <br />