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addition, Cedar Creek recommends that any future seed mixes use the vaseyana variety of big sagebrush <br />if this variety is not already employed in the seed mix. <br />Recommendation # 2 -Monitor Older Reclamation <br />It is also recommended that revegetation that has experienced at least seven growing seasons be <br />monitored every three years (i.e., year 10, 13, 16...) to gauge increases or decreases in forb and shrub <br />populations and to assess weed and annual brome control programs. Revegetation units of similar age <br />or logical geographic area should be combined for monitoring purposes as has previously been done for <br />Phase II Bond Release sampling. Distinctions between older seedings are very difficult to detect in the <br />field and are no longer necessary for monitoring purposes at 10+ years of age. <br />Recommendation # 3 -Continue Monitoring CSU Experimental Shrub Plots <br />Cedar Creek's final recommendation is that the CSU experimental shrub plots should continue to be <br />monitored annually and compared against success criteria to better track the value of experimental <br />techniques and allow modifications as necessary. This effort was initiated in 2005 with the establishment <br />of ten approximately 0.1 acre subplots and then expanded to twenty subplots in 2006. The oreliminarv <br />results of this studv should be viewed with caution as seeding of these Dlots coincidentally occurred in an <br />"excellent" shrub recruitment vear mine-wide If these plots were seeded one year earlier or later, the <br />shrub cover and densities most likely would have been considerably lower. For example, Unit EP042 <br />(adjacent to the shrub plots) was seeded with ashrub-only mix in 2002 and exhibited only 119 shrubs <br />per acre after four growing seasons. Large scale use of the techniques employed in the shrub study <br />(shrub-only mix, no topsoil) should be avoided due to the possibility of revegetation failure and erosional <br />instability. Cedar Creek recommends using shrub-only mixes and little or no topsoil applications on a <br />contour strip-seeding design alternating "experimental" techniques with typical seed mixes and topsoil <br />depths. This would provide shrubs and forbs a less competitive environment for germination and <br />seedling growth while providing erosional stability to the landform. It is also recommended the <br />experimental seeding unit (6" of overburden over topsoil), as approved by CDRMS, be established as <br />soon as practicable. Cedar Creek has found that shrubs and forbs germinate better in a nutrient-poor <br />growth medium, such as subsoil, and aggressive weeds and grasses fair poorer than on a topsoiled <br />surface. Once the shrubs, less aggressive grasses, and forbs roots reach the nutrient-laden topsoil <br />below, growth increases and erosional stability is reached. Cedar Creek has found that this technique <br />increases the diversity of all classes of vegetation and the quantity of shrubs. <br />Rio Tinto Energy America / Colowyo Mina Page 95 Revegetation Monitoring - 2006 <br />