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3.0 CONCLUSIONS & RECOMMENDATIONS <br />I • Conclusion <br />Overall the revegetation at Colowyo evaluated by Cedar Creek in 2006 can generally be considered <br />• good, sometimes very good, and in two cases (EP035 and 516017) excellent, and is typical of <br />• reclamation efforts at most Western coal mines. To the contrary, a couple of the units evaluated in 2006 <br />appear marginal and may require remediation depending on their progress, or lack thereof, over the next <br />one or two growing seasons, and / or whether annual brome populations become problematic. Having <br />an occasional revegetation effort that does not perform as expected is also a typical occurrence in <br />Western coal mine reclamation. <br />As revegetation units age, they tend to "thicken" with desirable (planted} species and exhibit <br />increased diversity, cover, and production. Most areas at Colowyo, with the exception of woody plant <br />density, are progressing well along the expected path toward exceeding success criteria by the end of <br />the 1o-year bond responsibility period. On occasion, units or portions of units have been identified as <br />requiring additional monitoring or some remedial attention, typically weed or annual brome control. The <br />continuing weakness present across Colowyo's revegetation efforts evaluated in 2006 is the generally low <br />density of woody taxa in comparison to the identified success criterion of 90% of 1000 stems per acre. <br />There are many factors contributing to this situation, however, Colowyo has started experimenting with <br />alternative reclamation techniques to address this issue. Early observation of these experiments shows <br />significant promise. Additional approaches for addressing this issue are addressed in Appendix AA. <br />Recommendation # 1-Seed Mix Changes <br />As recommended in 2004 and 2005 as well as based on field observation in 2006, Cedar Creek <br />would recommend increasing the amount of orchard grass in the seed mix. This grass species appears <br />to be a significantly preferred forage plant for resident elk. It is estimated that well over 90% of plants <br />encountered in the field exhibited signs of utilization. In many instances, plant identification was difficult <br />as utilization often exceeded 90% of the above ground biomass. Once this initial observation was <br />realized, it quickly became obvious that orchard grass was specifically targeted by elk. Given their <br />apparent zeal for this species, it might be possible to plant heavier patches of orchard grass in certain <br />locations about the mine to encourage animals away from areas that predispose adverse impact. In <br />Rio Tinin Energy America I Colowyo Mine Page 94 RavBgBWtion MORitgring - 2006 <br />