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(6) <br /> Reclamation efforts initiated on affected lands having major dis- <br /> turbance since June 1, 1977, have been relatively successful with <br /> respect to the establishment of a diversified flora on inactive <br /> tailings areas. A total of 14 species of the gramineae family and <br /> six species of forbs and shrubs have been planted on tailings ponds <br /> and all species are performing relatively well. In particular, two <br /> species of grass, Agropyron elongatum (Large) and Bromus inermis <br /> (Manchar) and one shrub, Artemisia (spp) have put on substantial <br /> growth during the past growing season (June 1-September 20) . Growth <br /> rates of these species, measured during the current year, are comparable <br /> to those of indigenous species inhabiting neighboring native soils. <br /> The only major disturbance site where difficulty has been encountered <br /> with respect to establishment of a diverse vegetative cover have been <br /> the inner areas of abandoned tailings ponds. The major factors con- <br /> tributing to this problem are low soil pH _(5.0-6.0) and the physical <br /> structure of the tailings material. Concentration of tailings fines <br /> (-200 mesh) at certain locations has precipitated the development of <br /> an impermeable surface layer. As a result, ponding occurs over local- <br /> ized areas during spring snowmelt and summer spates. This problem <br /> will have to be overcome by finding wetland species inhabiting alti- <br /> tude ranges similar to the Silverton area. One such species found <br /> locally, Baltic rush, does meet these requirements; however, no com- <br /> mercial seed source presently exists. Transplantation is the only <br /> present feasible means of establishing this species. Harvesting seed <br /> from native plants may also prove to be another way. <br /> Revegetation efforts on affected lands with moderate or minor dis- <br /> turbances have had a higher rate of success than similar work on areas <br /> having major disturbance. This is to be expected, since these areas <br /> are overlain by native soil material. Revegetation efforts on these <br /> areas is less intensive due to existing soil structure and availability <br /> of essential plant nutrients which yield higher survival rates for seed- <br /> ing and transplantation projects. The most successful species of grass <br /> planted on this area is Phleum pratense. -Tree species planted on the <br /> moderate or minor disturbed lands are also doing well. <br /> Soil Conservation Service <br /> Field Evaluation Planting Sitd <br /> The Soil Conservation Service (Durango office) , in conjunction with <br /> Standard Metals Corporation, established a Field Evaluation Planting <br /> during the summer of 1978. (See Appendis A-3. ) The purpose of the <br /> planting was to evaluate the performance of some 60 species of woody <br /> plants in order to determine which species would prove beneficial in <br /> the present revegetation program. As of September 20, approximately <br /> 50% of the plants transplanted are alive, but vigor is poor. Sur- <br /> vival rates measured next spring (1979) will determine the actual <br /> potential of individual species for use in the reclamation plan. <br /> -6- <br />