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<br />overstory closure (BLM 1994). The understory described by Tiedeman and <br />Terwilliger consists of Indian ricegrass, mutton bluegrass, western wheatgrass, <br />slender wheatgrass, and needle-and-thread (Tiedeman and Terwilliger 1978). <br />Mountain mahogany, big sagebrush, and flowery phlox are the dominant shrubs <br />on sites with more favorable soil and climatic characteristics. On sites where <br />rock outcrops occupy more than 30 percent of the area, the dominant shrubs are <br />common snowberry, Douglas rabbitbrush, antelope bitterbrush, creeping <br />barberry, and mountain mahogany. Forbs are not dominant in any of the <br />Pinyon-Juniper communities, but plains prickly pear is common at higher <br />elevations. <br />This community dominates upland hillsides at the Piceance Site, occurring primarily on <br />Rentsac channery sandy loam soils, the Torriorthents-Rock outcrop complex, and the <br />minor areas of the Redcreek-Rentsac complex soils that occur on the Piceance Site. This <br />community is used extensively as winter habitat for mule deer and summer habitat for <br />many small animals and birds (SCS 1982). <br />The Pinyon-Juniper Association comprises 1,916 acres (4'; percent) of the Piceance Site. <br />Of these, approximately 363 acres would be disturbed in the process of developing the <br />solution mining well field over the 30-year proposed mine life, with an additional <br />approximately 33 acres disturbed for project facilities. Construction disturbance would <br />affect approximately 165 acres of this vegetation type. Because of the long time <br />required to re-establish mature Pinyon-Juniper woodlands, impacts to all of these areas <br />would be long-term, even if young pinyon and juniper trees re-establish quickly in <br />vegetatated areas. <br />Chained Pinyon-Juniper Community -The Chained Pinyon-Juniper Community is a <br />result of vegetation manipulation performed in 1965 to provide increased <br />livestock forage. Dominant vegetation includes big sagebrush, Indian ricegrass, <br />bluebunch wheatgrass, needlegrass, and bluegrasses, with scattered small <br />pinyons and junipers (BLM 1982). This community occurs only on the flatter <br />ridgetops in the southwest section of the Piceance Site in the vicinity of the <br />proposed processing plant. Soils in this area are Rentsac channery loam or <br />Redcreek-Rentsac complex on which the potential plant community is as <br />described above for the Pinyon-Juniper Association. <br />T'he Chained Pinyon-Juniper Community comprises 311 acres (8 percent) of the <br />Piceance Site. Of these, approximately 63 acres would be disturbed in the process of <br />developing the solution mining well field over the 30-year proposed mine life, with an <br />additional approximately 8 acres disturbed for project facilities. Construction <br />disturbance would affect approximately 28 acres of Chained Pinyon-Juniper. <br />Sagebrush Association -The Sagebrush Association is influenced by many interacting <br />and independent ecological factors including climate, soils, topography, fire <br />J-3 <br />