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summer, resulting in a low requirement for the warm season grass component in overall <br /> forage composition and utilization. The cool season grass component can provide early <br /> spring green-up, fall regrowth, and standing "hay" forage in the winter. Thus, the <br /> reduction in seasonal variety will be mitigated by the type of established vegetation from <br /> the seed mix, local grazing patterns and the seasons grazed in the Nucla area. <br /> Woody Plant Density. As described earlier, a large proportion of the existing permit area <br /> has been disturbed either by agricultural or mining activities prior to implementation of <br /> the permanent regulatory program. In addition, the proposed postmining land use is <br /> dryland pasture or rangeland. While one subshrub (winterfat) and one shrub (fourwing <br /> saltbush) are included in the primary seed mix to mitigate the loss of premining woody <br /> plant densities, achievement of premining densities found in the upland sagebrush affected <br /> or reference areas is not practical or desirable for the postmining land uses. <br /> Furthermore, the reclaimed topography is generally a south or west facing aspect which <br /> provides poor sites for the planting of shrub seedlings. The very dry climate of the area <br /> further compounds the problem. Exhibit 22-1, "Postmine Vegetation Map - Nucla Mine", <br /> illustrates those areas that will provide the best planting sites for shrubs and trees in <br /> the reclaimed areas. The planting rate for dry sites will be 500 stems/acre. Expected <br /> mortality on these sites is 50 percent, thus the live stem success standard will be 250 <br /> stems/acre. The planting rate for the moist sites will be 1,000 stems/acre with an <br /> expected mortality of 25 percent. The live stem success standard will be 750 stems/acre. <br /> While these densities may appear low, grouping or concentrating the planting area will <br /> increase the effectiveness. Also, the establishment of fourwing saltbush and winterfat <br /> from seed in the mix and the invasion of rubber rabbitbrush (Chrvsothamnus nauseosus) and <br /> big sagebrush (Artemisia tridentate) from surrounding areas will further enhance overall <br /> woody plant densities. Additionally, at least one shrub must have a minimum relative <br /> cover value of 3 percent as part of the species diversity requirement. This will insure <br /> that woody plants occur throughout the reclaimed areas. . Finally, the availability of <br /> native stands adjacent to the south and eastern portions of the permit area that contain <br /> high densities of shrubs provide significant habitat and will further mitigate for lower <br /> densities on the mine permit area. <br /> Nucla East Area <br /> Postminin9 Land Use. land use and baseline vegetation studies (Tabs 4 and 10) conducted <br /> during 1987, as well as results from interviews with local operators in the area, show <br /> 22-15 Revised 07/25/91 <br />