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Species Composition (2012) <br />* Numbers reflect only those species meeting the relative importance percentage limitation <br />Reclamation Areas 23, 29, and 31 did not satisfy the final species composition <br />revegetation success criteria this season. Reclamation Areas 23 and 29 each lacked one <br />cool season graminoid to meet the species composition success criterion. Calamovilfa <br />longifolia exceeded the 40% maximum criterion in both Reclamation Area 23 and 29 <br />thereby disqualifying it from counting in the species composition total. Reclamation <br />Area 30 exceeded the final species composition revegetation success criteria this season, <br />having two more perennial species than required, one more warm season grass species <br />than required and one more cool season grass than required. Reclamation Area 31 did not <br />satisfy the final species composition revegetation success criteria this season, lacking two <br />qualifying warm season grass species to meet the required compliment. As with <br />Reclamation Areas 23 and 29, Calamovilfa longifolia exceeded the 40% maximum <br />criterion and was disqualified from contributing to the species composition total. <br />4.0 DISCUSSION AND CONCLUSIONS <br />Reclamation Areas 23, 29, 30, and 31 were quantitatively sampled in 2012 to evaluate <br />revegetation establishment for monitoring purposes, and identify any areas that require <br />implementation of additional measures to ensure long -term revegetation success. <br />4.1 2012 PRECIPITATION REGIME <br />The climate of the mine and surrounding area is characterized by a wide temperature <br />fluctuation; from below freezing in winter, to very warm in the summer months. <br />Precipitation in the area is provided by weather systems originating in the Gulf of Mexico <br />and is most frequent and reliable during the spring and late summer months (Table 7). <br />CEC has collected precipitation data at the mine for a number of years. This data <br />represents the most complete record of precipitation from the mine area. Table 7 presents <br />a summary of precipitation data collected from 1993 through 2012, corresponding with <br />the vegetation monitoring. A review of the data illustrates that precipitation generally is <br />lowest during the late autumn and winter months (October through March), peaks in <br />April through June, and tapers off gradually until late autumn. The months with the <br />Coors Energy Company Keenesburg Mine Page 16 <br />2012 Revegetation Monitoring Report <br />Success <br />Standard <br />Reel. Area <br />23 <br />Reel. Area <br />29 <br />Reel. Area <br />30 <br />Reel. Area <br />31 <br />Total Perennial Species* <br />(40 % >rel. cover >3%) <br />4 <br />3 <br />3 <br />6 <br />3 <br />Warm Season Grasses* <br />3 <br />3 <br />3 <br />4 <br />l <br />Cool Season Grasses* <br />1 <br />0 <br />0 <br />2 <br />2 <br />Relative % Cover <br />(3%<x>40%) <br />All Species <br />All Species <br />All Species <br />All Species <br />All Species <br />Species Composition (2012) <br />* Numbers reflect only those species meeting the relative importance percentage limitation <br />Reclamation Areas 23, 29, and 31 did not satisfy the final species composition <br />revegetation success criteria this season. Reclamation Areas 23 and 29 each lacked one <br />cool season graminoid to meet the species composition success criterion. Calamovilfa <br />longifolia exceeded the 40% maximum criterion in both Reclamation Area 23 and 29 <br />thereby disqualifying it from counting in the species composition total. Reclamation <br />Area 30 exceeded the final species composition revegetation success criteria this season, <br />having two more perennial species than required, one more warm season grass species <br />than required and one more cool season grass than required. Reclamation Area 31 did not <br />satisfy the final species composition revegetation success criteria this season, lacking two <br />qualifying warm season grass species to meet the required compliment. As with <br />Reclamation Areas 23 and 29, Calamovilfa longifolia exceeded the 40% maximum <br />criterion and was disqualified from contributing to the species composition total. <br />4.0 DISCUSSION AND CONCLUSIONS <br />Reclamation Areas 23, 29, 30, and 31 were quantitatively sampled in 2012 to evaluate <br />revegetation establishment for monitoring purposes, and identify any areas that require <br />implementation of additional measures to ensure long -term revegetation success. <br />4.1 2012 PRECIPITATION REGIME <br />The climate of the mine and surrounding area is characterized by a wide temperature <br />fluctuation; from below freezing in winter, to very warm in the summer months. <br />Precipitation in the area is provided by weather systems originating in the Gulf of Mexico <br />and is most frequent and reliable during the spring and late summer months (Table 7). <br />CEC has collected precipitation data at the mine for a number of years. This data <br />represents the most complete record of precipitation from the mine area. Table 7 presents <br />a summary of precipitation data collected from 1993 through 2012, corresponding with <br />the vegetation monitoring. A review of the data illustrates that precipitation generally is <br />lowest during the late autumn and winter months (October through March), peaks in <br />April through June, and tapers off gradually until late autumn. The months with the <br />Coors Energy Company Keenesburg Mine Page 16 <br />2012 Revegetation Monitoring Report <br />