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Reference Area Characterization <br />The Reclaimed Irrigated Pastureland reference area is a typical irrigated pasture in the Nucla <br />area. The reference area is adjacent to the mine and contains many of the same soils which <br />are present in the reclaimed area. Vegetation is almost entirely herbaceous species, mainly <br />introduced perennial pasture grasses planted for livestock forage. Flood irrigation results in <br />uneven water application, and as a result the species composition within the reference area <br />varies with soil moisture. On most of the reference area where soil moisture is moderate, at <br />least 8 species of upland perennial grasses are dominant, with Kentucky bluegrass, tall fescue, <br />wheatgrasses, and meadow fescue the most dominant (Attachment 2.05.4(2)(e)-5 shows <br />production and cover summary data from 2007 vegetation sampling, and scientific names of <br />plants). Desirable perennial forbs are much less common, and include mainly Alsike clover with <br />minor amounts of dandelion. In shallow drainageways the soil is saturated during the growing <br />season and wetland plants dominate primarily various species of sedge and rush with minor <br />amounts of tufted hairgrass, buckhorn plantain, common plantain, and rarely cattail. <br />In June 2007, mean cover of total vegetation measured at 15 transects was 71.9% (see <br />Attachment 2.05.4(2)(e)-5). Most of the remaining cover was litter, with very little bare ground <br />(3.5%). Most of the vegetation is desirable (perennial grasses, grass -like plants, and forbs, <br />excluding noxious weeds), comprising 68.6% cover. Of these, Kentucky bluegrass and tall <br />fescue contribute nearly 48% relative cover (the fraction of total vegetation cover), and sedges, <br />rushes, and wheatgrasses comprise 32% relative cover. Among life forms, desirable perennial <br />grasses (including sedges and rushes) are dominant by far (64% cover, 89% relative cover), <br />and desirable perennial forbs (primarily Alsike clover) are next (4.5% cover, 6.2% relative <br />cover). Undesirable species together comprise total cover of 3.3% and relative cover of 4.6%. <br />These include shrubs (gumweed), a few weedy annual forb species, and the noxious weed field <br />bindweed; each of these life forms contributes 1.5% or less total cover. <br />Mean total production measured in June 2007 at 44 plots was 2,677 Ib/acre for all vegetation, <br />and 2,513 Ib/acre for desirable vegetation. Perennial grasses (including sedges and rushes) <br />contribute most of the production, at 2,436 Ib/acre (97% of desirable production and 91% of <br />total production). Forbs made up most of the remaining plant production, with a minor <br />contribution from shrubs (gumweed) and the noxious weed species field bindweed. <br />August 2013 PR -08 2.05.4(2)(e) - 26 <br />