2009-03-16_REVISION - C1981028 (4)

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grasses from the seed mix applied to the 1986 and 1987 reclaimed areas, yielding a slightly different species composition. • The 1986 reclamation areas encompass approximately 51 acres of reclaimed pit in the central area of the Keenesburg Mine permit area. The 1986 reclamation area is composed of three parcels (Areas 4, 12, and 20) separated by north-south haul road corridors (Areas 3 and 19). The area is nearly flat with a gentle slope (<1 °) to the north and east. Reclamation and coincident revegetation within this area took place in 1986. Replaced soils were sandy in texture. The 1987 reclamation areas encompass approximately 39 acres of reclaimed pit and adjacent areas in the south central area of the Keenesburg Mine permit area. The 1987 reclamation area is composed of two parcels (Areas 11 and 17) separated by a north-south haul road corridor and three narrow reclamation parcels (Areas 9, 10, and 16). The entire 1987 reclamation area is nearly flat with a gentle slope (<1 °) to the south and east. Reclamation and subsequent revegetation within this area took place in 1987. Replaced soils were generally sandy in texture. Specific sampling information for the 1985, 1986, and 1987 reclamation areas is contained in Tables 1, 2, and 4. 3.1.1.1 Vegetation Cover Total vegetation cover of the 1985, 1986, and 1987 reclamation areas was 60.80 percent. • Graminoids provided 39.80 percent mean cover (67.60% relative cover) and forbs accounted for 18.20 percent mean cover (26.10% relative cover). Succulents and shrubs each accounted for 1.40 percent total cover (2.81 and 3.48% relative cover, respectively). The lowest total vegetation cover of the parcels sampled was found in Area 4 (42%) and the highest cover (74%) was found in Area 11. No single species was encountered in all the cover transects, though Calamovilfa longifolia (prairie sandreed) was encountered in 90 percent of the transects, Bromus marginatus (mountain brome), Helianthus annuus (sunflower), and Kochia scoparia (kochia) in 85 percent of all transects, Bouteloua gracilis (blue grama) was found in 80 percent of all transects, and Andropogon hallii (sand bluestem) and Sporobolus cryptandrus (sand dropseed) were present in 70 percent of all cover transects. Calamovilfa longifolia, a warm season native prairie grass, accounted for the highest overall vegetation cover with 13.30 percent mean cover and 24.10 percent relative cover in the 1985, 1986, and 1987 reclamation areas. Eight additional species contributed significantly to vegetation cover (greater than 3% relative cover); the cool season native perennial grass Bromus marginatus with 10.20 percent mean cover and 15.53 percent relative cover, the native warm season annual forb Helianthus annuus contributed 9.70 percent mean cover (14.06% relative cover), the warm season native Bouteloua gracilis provided 5.00 percent total vegetation cover and 9.37 percent relative cover, warm season native graminoid Andropogon hallii accounted for 4.40 percent mean cover (7.50% relative cover), Kochia scoparia, the introduced annual forb, contributed 5.00 percent total cover (6.83% relative cover), the warm season native grass Sporobolus cryptandrus provided 2.50 percent mean . total cover (3.88 percent relative cover), the native shrub Artemisia filifolia (sand sage) Coors Energy Company Keenesburg Mine Page 9 2007 Phase III Vegetation Study