REP10902 - Laserfiche WebLink

Home Browse Search

c. R _Q Randy Price - 2 - April 22, 1985 The low diversity of species on the individual plots is notable, but is likely a reflection of the lack of variability within the plots. On the reclaimed mine site, variation in topsoil depth, slope, aspect and topographic position should create conditions favorable for a wider variety of species. Mulch Comparison Plots Mulch comparison plots established in 1978 were also thought to have been affected by excessive compaction. Two ripping treatments were applied on the mulch comparison plots in 1980. Analysis of the mulch plots this summer should include an evaluation of the effectiveness of the ripping treatments. 1984 Sand Over Clay Test Plots Grasses were observed to be germinating on the overburden pile test plats which were seeded last fall. It will be important for Coors to collect first year cover or density data (by species) on the p ots later this summer. It is possible that the fall seeding will favor the co2~1 season grasses such as western wheatgrass, crested wheatgrass and pubescent wheatgrass over the warm season grasses which are not able to exploit the early spring moisture. Coors should submit a revegetation monitoring plan for both test plot and non-test plot revegetation. Long-Term Spoil and Topsoil Stockpile Revegetation The spoil stockpile is stabilized by a vigorous stand of pubescent, western and crested wheatgrass. Apparently, seedmix 1 which is limited to quick-growing cool season species was used on the spoils, though records were not available to substantiate this. Over the major portion of the pile a sandy material was present on the surface to a depth of at least one foot. The grasses are not growing directly in a clay or shale overburden. Growth on the topsoil or "tops and" pile adjacent to the spoil stockpile is less dense and is composed of different species. Evidently, seedmix 2 was seeded on the topsoil. A fairly good stand of warm season grasses including blue grama, prairie sandreed, sand bluestem and switch grass has been established on the west facing slope of the pile. Seeding was less successful on the top and east facing slope of the pile and growth is limited primarily to sand dropseed and crested wheatgrass. Other The operator indicated that 'pastura' little bluestem will be substituted in the seedmix for 'Cimarron' little bluestem. "pastura' is a variety which has been selected for harsh sites and has been recommended by the SCS for use in the Central High Plains Resource Area (in which the Keenesburg Mine is located). The substitution is appropriate.