2011-03-24_REPORT - C1981019 (10)

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2.2.5 EIP044 EP044 is comprised of 24.6 acres of moderately sloping revegetation that has a predominately east aspect. This unit was seeded in 2003, making 2010 the seventh growing season. A total of 36 plant taxa were observed in the unit (Table AB-1). Current annual production across the unit averaged 1,261.5 6 pounds per acre in 2010 with perennial grasses and annual forbs the dominant categories (Table 1 and3R«,«,:` Chart 2). Ground cover in EP044 consisted of 50.8% 11 l/fi l1 td f4 live vegetation, 1.1% rock, 35.8% litter, and bare , ., 4, soil exposure of 12.4%. Perennial cover across the ; unit averaged 28.9%. Dominant taxa were - " -, thickspike wheatgrass, cheatgrass, and western wheatgrass with 11.6%, 9.7%, and 3.6% average cover, respectively. Sub-dominant taxa include Kentucky bluegrass, Japanese brome, and basin wildrye with 3.2%, 2.3%, and 2.0% average cover, respectively. Woody plant density was determined coy.,o mire -aereae? rwneoam ?ro.'= w . from 20 belt transects. Density (Table 3) totaled Epo" zero young and mature stems per acre. With regard to diversity, EP044 exhibited five perennial grasses with between 3% and 50% relative cover and relative forb cover of 27.4% (excluding noxious weeds). This unit readily passes the production bond release criterion, but fails the cover comparison (Charts 1 and 2). Unit EP044 currently passes the diversity standard set forth by TR-72 (Charts 3 and 4), but qualified shrub acres need to be properly delineated. Given that there were zero shrubs per acre identified in the woody plant density transects, expectations are that this unit will need to be grouped with adjacent units to meet the woody plant density standard of 150 stems per acre on 3% of the reclaimed land. Shrub patch delineations/enumerations are slated for spring 2011. Noxious weeds appear to be controlled in this unit. Annual bromes are present with 12.0% cover, down from 40.3% in 2007. Unit EP044 exhibits good production and diversity for seven-year old revegetation. However, the cover values exhibited by this unit should be considered below average. Perennial cover has decreased since 2007; however the relative cover by perennials is showing improvement - from 44.0% in 2007 to 56.8% in 2010. There are still patches of thin cover and spot reseeding may need to be considered if natural seed dispersal is insufficient. More time is necessary before it can be determined with certainty that this unit is on an appropriate trajectory for bond release. If future monitoring reveals expansion of annual species, chemical control may be recommended in conjunction with spot reseeding. Overall, Unit EP041 should be monitored again in 2013, but solutions for meeting the shrub standard need to be discussed. Cedar Creek Associates, Inc. 20 Colowyo Mine 2010 Revegetation Monitoring Report