Laserfiche WebLink
diverse, which provides a robust vegetation stand able to resist some variability in irrigation water <br />application or grazing regimes. Some drier areas tend to be dominated by weedy annual forbs, <br />gunweed, and occasionally cheatgrass, but these areas make up only a small fraction of the <br />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 forage <br />were seeded including perennial grasses and forbs such as alfalfa and clover. These irrigated <br />pastures are intended primarily to provide winter forage for livestock, and secondarily to provide <br />cut hay. Uneven application of flood - applied water is typical because of variable terrain, and wet <br />areas soon become dominated by wetland grasses and forbs, and sometimes Russian -olive or <br />emergent wetland plants such as cattail or bulrushes. Weedy annual forbs and cheatgrass typically <br />become established on drier sites, and many become dominant in disturbed areas. The species <br />composition and ecological condition of pre -mine irrigated pastures in the permit area varies widely <br />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 Tables 2.05.4(2)(e) -5 and Attachment <br />2.05.4(2)(e) -2) shows that the reference area vegetation is similar to pre -mine vegetation in the <br />irrigated pasture type. The 1987 total vegetation cover was 71.8% and dominated by perennial <br />graminoids, mostly seeded pasture grasses with Kentucky bluegrass the most dominant, all similar <br />to the 2007 reference area measurements. Mean herbaceous production was measured at 2,823 <br />lb/acre, similar to the 2007 reference area mean. <br />Revised April /09 TR58 <br />2.05.4(2)(e) -19F <br />f - LI <br />13 rvjby 2W? <br />