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The reference area pasture is in good ecological condition. Soil erosion is minimal, there are no <br />significant gullies or rills, and very little bare ground. Desirable plant species composition is <br />diverse, which provides a robust vegetation stand able to resist some variability in irrigation <br />water application or grazing regimes. Some drier areas tend to be dominated by weedy annual <br />forbs, gunweed, and occasionally cheatgrass, but these areas make up only a small fraction of <br />the reference area, and are typical of flood -irrigated pastures in the Nucla area. <br />The reference area vegetation is representative of the pre -mine irrigated pasture type in the permit <br />area. Irrigated pastures in the permit area were originally mostly dominated by native sagebrush <br />shrublands or pinyon juniper woodlands. When converted to irrigated pasture, trees and shrubs <br />were typically removed mechanically or by flooding, and plant species desired for livestock <br />forage were seeded including perennial grasses and forbs such as alfalfa and clover. These <br />irrigated pastures are intended primarily to provide winter forage for livestock, and secondarily to <br />provide cut hay. Uneven application of flood -applied water is typical because of variable terrain, <br />and wet areas soon become dominated by wetland grasses and forbs, and sometimes Russian - <br />olive or emergent wetland plants such as cattail or bulrushes. Weedy annual forbs and cheatgrass <br />typically become established on drier sites, and many become dominant in disturbed areas. The <br />species composition and ecological condition of pre -mine irrigated pastures in the permit area <br />varies widely depending on irrigation water availability and management history. <br />A comparison of the 2007 vegetation data in the reference area with pre -mine studies conducted <br />by Peabody Coal Company in 1987 and WFC in 1999 (in Attachment 2.05.4(2)(e)-5) and <br />Attachment 2.05.4(2)(e)-2) shows that the reference area vegetation is similar to pre -mine <br />vegetation in the irrigated pasture type. The 1987 total vegetation cover was 71.8% and <br />dominated by perennial graminoids, mostly seeded pasture grasses with Kentucky bluegrass the <br />most dominant, all similar to the 2007 reference area measurements. See Table 2.05.4(2)(e)-3. <br />Mean herbaceous production was measured at 2,823 lb/acre, similar to the 2007 reference area <br />mean. <br />In 1999, estimates of mean cover in 2 subjectively selected irrigated pastures (deemed <br />representative of "typical" conditions) were also similar, showing perennial grass cover of <br />44.5%, perennial forb cover of 33.3%, and total desirable vegetation cover of about 79%. <br />Annual herbaceous production was estimated at 4,153 lb/acre. The 1999 mean is higher than <br />January 2015 TR -66 2.05.4(2)(e) - 26 <br />