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• <br />Plant Species % Relative Cover <br />Change 2007-2009 +/- <br />,4mbrosia silostach a 2110 <br />Kochia sco aria 517 <br />Andro 0 on hallii 390 <br />Medica o lu ulina 176 <br /> <br />Bromus tectorum -9 <br />Lactuca serriola -23 <br />Melilotus ofcinale -35 <br />Or zo sis h menoides -42 <br />Panicum vir atum -48 <br />Helianthus annuus =59 <br />Sisymbrium altissimum -82 <br />Changes in relative cover on a yearly basis may not reflect long term trends but should reveal <br />individual species responses to precipitation distribution and competition from other species. <br />The changes in relative cover from 2007-2009 reveal changes in species representation from <br />an average growing season to a wet growing season (with regard to precipitation). <br />Significant increases in relative cover occurred in the past two growing seasons for one cool <br />season perennial forb (Ambrosia psilostachya), one warm season perennial grass <br />(Andropogon hallii), and two annual introduced early successional forbs (Kochia scoparia <br />and Medicago lupulina). Remaining species present in both 2007 and 2009 sampling <br />• revealed major decreases in relative cover over the past two growing seasons. Annual forbs <br />continue to dominate the relative cover of the 2002 reclamation areas in the sixth growing <br />season. Typically by this timeframe, several species of warm season and cool season <br />perennial graminoids have established themselves as dominant within the vegetation <br />community. <br />4.2.2 2006 Reclamation Area <br />• <br />This calendar year was the first quantitative vegetation sampling of the 2006 reclamation <br />area. Cover sampling revealed significant cover and diversity of the perennial grass <br />component in the area. Of the nine grass species encountered, seven were native perennials. <br />Of the perennial grasses, four were warm season and three were cool season. Introduced <br />annual early successional forbs were only a minor component of the sampled cover. <br />4.3 HERBACEOUS PRODUCTION <br />Mean herbaceous production for both the 2002 and 2006 reclamation areas significantly <br />exceeded the predicted total herbaceous production (135.07g/m2). A 91.1 percent increase in <br />total herbaceous production occurred from 2007 to 2009 at the 2002 reclamation areas. Not <br />entirely attributable to a corresponding precipitation regime, the increased production is <br />likely resultant from establishment of large stature species. <br />Coors Energy Company Keenesburg Mine <br />2009 Revegetation Monitoring Report <br />Page 14