Laserfiche WebLink
The 1997 reclamation areas sampled encompass approximately 18 acres of reclamation in <br />four distinct areas within the Keenesburg Mine permit area. The areas are found throughout <br />• the disturbance area of the mine and include Area 3 that is a road corridor between the <br />1985/1986 central reclamation areas and the 1986 east area, Area 14 (an area to the west of A <br />pit), and Areas 18 and 21, two areas adjacent to B pit. The 1997 reclamation areas are nearly <br />flat overall with a gentle slope (1-3°) to the north. Reclamation and coincident revegetation <br />with the permanent seed mix took place during the autumn of 1997 within these areas. <br />Replaced soils were sandy in texture. <br />Specific sampling information for the 1995 and 1997 reclamation areas is contained in Tables <br />1, 3, and 5. <br />3.1.2.1 Vegetation Cover <br />Total vegetation cover of the 1995 and 1997 reclamation areas was 59.20 percent (Table 3). <br />Graminoids provided 52.40 percent mean cover (90.52% relative cover), forbs accounted for <br />6.67 percent mean cover (9.30% relative cover), and one succulent provided 0.13 percent <br />mean cover and 0.18 percent relative cover. The lowest total vegetation cover of the 1995 and <br />1997 reclamation areas sampled was found in Areas 1, 24, and 26 (54%) and the highest was <br />in Area 28 (70%). Calamovilfa longifolia was encountered in all the cover transects, <br />Sporobolus cryptandrus was encountered in 93 percent of the transects, Bromus marginatus <br />was present in 73 percent of all transects, and Agropyron smithii (western wheatgrass) and <br />Bouteloua gracilis were found in 60 percent of all transects. <br />is Calamovilfa longifolia, Bromus marginatus and Sporobolus cryptandrus were co-dominant <br />with regard to vegetation cover in the 1995 and 1997 reclamation areas. Bromus marginatus <br />provided 13.33 percent vegetation cover and 18.60 percent relative cover while Calamovilfa <br />longifolia contributed 11.60 percent mean cover and 19.14 percent relative cover and <br />Sporobolus cryptandrus accounted for 11.07 percent total vegetation cover and 18.60 percent <br />relative cover. Four additional species contributed significantly to vegetation cover (greater <br />than 3% relative cover); Bouteloua gracilis contributed 4.53 percent mean cover (11.45% <br />relative cover), Bouteloua curtipendula (sideoats grama) provided 3.07 percent total <br />vegetation cover and 7.16 percent relative cover, Agropyron smithii accounted for 4.13 <br />percent mean cover (6.44% relative cover), and Ambrosia psilostachya contributed 2.67 <br />percent mean and 3.94 percent relative cover. <br />Vegetative litter (prior years growth, dead wood, and other biologic organic material) <br />comprised 25.33 percent ground cover overall within the 1995 and 1997 reclamation areas. <br />Bare soil comprised 15.47 percent of the ground cover. No rock or cryptogams were <br />encountered during the cover sampling in the 1995 and 1997 reclamation areas. <br />3.1.2.2 Herbaceous Production <br />Overall mean total herbaceous production within the 1995 and 1997 reclamation areas this <br />year was 174.86 g/m2 (1559 lb/ac). <br />. 3.1.2.3 Species Composition <br />Coors Energy Company Keenesburg Mine Page 11 <br />2008 Phase III Vegetation Study