REP23842 - Laserfiche WebLink

Home Browse Search

~• ,~ ~~ ~J '• ~• 'i~ Perennial grass production dominated total herbaceous production for all reclaimed azeas in 1995, ranging from 80.5 to 94.5 percent of the total herbaceous production. Perennial grass production from the Osgood Sand Reference Area was also the dominant component, totaling 58% of the total production. Interestingly, the forb component contribution to herbaceous production rose significantly from 1994 to 1995 in three of the four areas sampled. In the Osgood Sand Reference Area forb herbaceous production rose from ]1.5 percent to 40.8 percent. In the 1985 Reclamation Area the forb contribution doubled from 3.0 to 6.8 percent. In the 1987 Reclamation Area the forb contribution increased by more than 2000 percent from 0.9 to 19.1 percent. The only azea that did not show an increase in forb representation was the 1986 Reclamation Area. Forb representation in herbaceous production dropped slightly from 1944 to 1995 (6.640 to 4.546). SPECIES COMPOSITION The Colorado Division of Minerals and Geology considers species composition of the revegetated and reclaimed areas to be an indicator of successful vegetation establishment. A standard has been set by CDMG for the evaluation of species composition at the Keenesburg Mine. To be judged successful, at final bond release, this standard requires that, "the species composition on the reclaimed azea is such that there aze at least seven perennial species of which four are warm season grasses and one is a forb. No one component of the above species should comprise greater than 4046 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 cc~~ introduced." Species presence and representation on the reclaimed azeas as well as the reference azea was significantly greater in terms of absolute numbers than in 1994. A comparison of the 1995 species composition data with the revegetation success standard reveals that none of the azeas sampled in 1995 would meet the species composition success standazd. The azea with the lowest number of qualifying species was the 1986 Reclamation Area. This area had six species (three warm season grasses, two cool season grasses, and one forb) with the required relative importance. However, two species were disqualified; one being an "undesirable" annual grass and the other being an annual forb (even though it is a native species). The 1985 Reclamation Area had the most perennial species within the relative importance constraints of the standazd. The 1985 area met the warm season grass requirement, but did not meet the perennial forb requirement. The 1987 Reclamation Area had five qualifying perennial species, and lacked two warm season grasses and one forb with sufficient relative cover to meet the standard. -14-