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wisdom of using a seedmix containing numerous aggressive introduced grasses, <br />as well as a diverse assemblage of native species, (particularly as represented <br />by the Large Permanent Sites mix). It may be unrealistic to expect that use of <br />seed mixes containing the introduced grasses will ultimately result in revegetated <br />stands that contain a significant native component, including big sagebrush and <br />associated species. Even the relatively modest standards in the current permit <br />for native species, forbs, and woody plants may not be compatible with use of <br />the aggressive introduced grasses in the current seedmix (including crested, <br />desert, Siberian, and pubescent wheatgrass, smooth brome, Russian wildrye, <br />and sheep fescue). <br />Incompatibility of even relatively minor components of these species with <br />establishment of diverse native communities has been borne out by monitoring <br />results and observations at other mines in northwestern Colorado, and reports <br />from the current technical literature for the western U.S. (see, for example, <br />Monsen, 2005. Restoration Manual for Colorado Sagebrush and Associated <br />Shrubland Communities). Qualitative vegetation survey reports included within <br />recent Deserado Annual Reclamation reports indicate dominance by one or <br />more of these species on permanent reclamation sites seeded in the 1980's at <br />Deserado (with fourwing saltbush and rabbitbrush present in some areas, but no <br />significant establishment or invasion of big sagebrush or associated native <br />forbs). More recently, Refuse Area No. 1 at Deserado was seeded in 1997 with <br />a diverse mix similar to the currently approved Large Sites mix. Reports indicate <br />that portions of the pile not dominated by cheatgrass are dominated by the <br />introduced grasses, along with one or two native perennial grasses. Seeded <br />forbs are apparently very minimally represented, with shrubs somewhat better <br />represented, but apparently at densities still well below the approved 500 stem <br />per acre standard. <br />The pervasive presence and high density of cheatgrass within sagebrush and <br />greasewood communities in the mine vicinity represents a very significant <br />obstacle to successful establishment and a threat to long term stability of <br />revegetation stands at Deserado. The documented ability of the various <br />introduced grass species to compete with cheatgrass (particularly the species in <br />the crested wheatgrass complex) is the primary reason for their inclusion in the <br />Deserado seedmixes. Various native species that are more compatible with <br />establishment of native sagebrush community components have also been <br />recommended in the literature for their ability to compete with cheatgrass (e.g. <br />bottlebrush squirreltail, Sandberg bluegrass, mutton bluegrass, prairie junegrass, <br />`Anatone' bluebunch wheatgrass, streambank wheatgrass, Pacific aster, blue <br />leaf aster, and rubber rabbitbrush), but performance of the native species in this <br />regard is not as well documented as the introduced grasses. The introduced <br />sub-shrub forage kochia has been recommended by various authorities as a <br />useful species due to its ability to compete with cheatgrass (among other <br />attributes), and for its apparent compatibility with other species in diverse <br />10 <br />