2009-03-16_REVISION - C1981028 (4)

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4.0 DISCUSSION AND CONCLUSIONS • 4.1 VEGETATION COVER Both the 1985, 1986, and 1987 reclamation areas and the 1995 and 1997 reclamation areas exceeded the final revegetation success criterion value (23.13%) for total vegetation cover. The 1985, 1986, and 1987 reclamation areas had a mean total vegetation cover of 63.20 percent and the 1995 and 1997 reclamation areas had a mean total vegetation cover of 59.20 percent. The second year of quantitative vegetation cover sampling for Phase III bond and liability release reveals that the requirement for vegetation cover has been met. 4.2 HERBACEOUS PRODUCTION The 1985, 1986, and 1987 reclamation areas and the 1995 and 1997 reclamation areas exceeded the final revegetation success criterion value (39.66 g/m2) for total herbaceous production. The 1985, 1986, and 1987 reclamation areas had a mean total herbaceous production of 144.68 g/m2 and the 1995 and 1997 reclamation areas had a mean total herbaceous production of 174.86 g/m2. The second year of quantitative vegetation cover sampling for Phase III bond and liability release reveals that the requirement for total herbaceous production has been met. 4.3 SPECIES COMPOSITION • The species composition standard requires that there be at least four perennial species, of which three are warm season grasses and one a cool season grass. No one component of the above four species should comprise greater than 40% relative importance nor less than 3% relative importance. Relative importance will be measured by calculating relative cover of the revegetation species. Vegetation species which may be used in the calculation of species composition may be any plant species not defined as a noxious or prohibited plant species, and may be native or introduced. Both the 1985, 1986, and 1987 reclamation areas and the 1995 and 1997 reclamation areas satisfied the final species composition revegetation criteria. The 1985, 1986, and 1987 reclamation areas had seven qualifying perennial species, four qualifying warm season graminoids and two qualifying cool season graminoids. The 1995 and 1997 reclamation areas had seven qualifying perennial species, four qualifying warm season graminoids and two qualifying cool season graminoids. The second year of quantitative vegetation cover sampling for Phase III bond and liability release reveals that the reclamation areas have exceeded the final revegetation success requirements for species composition. 5.0 SUMMARY The quantitative vegetative cover, herbaceous production, and species composition data • indicate that the permittee has established a diverse, effective, and permanent vegetative cover of the same seasonal variety as the original vegetation. The revegetated area is capable Coors Energy Company Keenesburg Mine Page 14 2008 Phase III Vegetation Study