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• smithii), slender whea tg ra ss, and mountain brome. As with the forb production in the <br />other vegetation types, nearly all was made up by perennial native forbs. Production <br />among perennial native forbs was usually rather evenly distributed so that much of the <br />production was in the category of combined minor perennial native forbs. The major <br />individual species were lupines; other major species included western yarrow, showy <br />fleabane, showy goldeneye (Hel iomeris multiflora), and common yampa. <br />Avera a herbaceous 2 <br />g productivity of the reference area (Table 4-24) was 84.5 g/m (754 <br />2 <br />16/acre) compared to 126.1 g/m (1125 16/acre) for the proposed mine area (Table 10-3). <br />Haul Road Corridor. The haul road corridor permit area originates on the Dry Creek Road <br />approximately two miles south of Hayden, and runs eastward and northward approximately <br />four miles to the vicinity of the Hayden Station Power Plant. Topography of the corridor <br />consists of low rolling hills cut by drainages containing ephemeral streams. A large <br />majority of the corridor crosses dryland wheat fields. Alkali sagebrush, low sagebrush <br />(A. arbuscula), mountain big sagebrush (A. tride nta to ssp. vaseyana), and relatively small <br />greasewood communities occupy steep hillsides or lowland areas where soils are unsuitable <br />• for dryland farming. Meadow communities occupy the drainageway s. The haul road corridor <br />covers an area approximately 21,600 feet long with varying widths for a total acreage of <br />214.5 acres (Table 10-2). Actual acres affected will be close to the total for the permit <br />area. The revised haul road permit area associated with the 1989 realignment is shown on <br />revised Exhibit 10-2. <br />Low Sagebrush. The Low Sagebrush type is the most extensive (40.4 acres) natural <br />vegetation type in the corridor study area (Exhibit 10-2 ). In 1985, a verification <br />vegetation study was conducted on a realigned portion of the tie across haul road route. <br />The study area is located in the approximate center of the SE?. NEB Section 24, T6N, RBBW. <br />In this study, the sagebrush type was referred to as a "mixed sagebrush type" because of <br />both low and medium height growth forms of th two big sagebrush subspecies. The mixed <br />sagebrush type corresponds to the low sagebrush type in this tab. The type, or types, <br />occur primarily on north-, west-, and south-facing hillsides occupied by the Bulkley Clay <br />soil series. Slopes range from about 1 to 10 percent. Data is presented in Appendix 10-5 <br />and the report for the verification vegetation studies is contained in Appendix 10-8. An <br /> additional 4.4 acres (additional to the original 36 acres) of this type are included in <br />• areas associated with the haul road realignment of 1989 (see revised Exhibit 10-2). <br />25 <br />