Laserfiche WebLink
Juniper Scrub and Cropland. Disturbance boundaries have not been projected with specificity <br />for the proposed Lower Wilson expansion area. <br />B. Plant Establishment <br />Colowyo will establish on all affected lands within the permit area a diverse, effective and <br />permanent vegetative cover such as is necessary and desirable to achieve the approved <br />post-mining land use of wildlife and grazing. Details of the mine's revegetation plan are <br />discussed beginning on page 2.05-42 of Section 2.05.4 of the original Permit volumes. The <br />permanent seed mixtures to be planted are found on Tables 2.05-7, 2.05-8, and 2.05-9, within the <br />narrative of Section 2.05.4. These seed mixes were approved in April 2002, within TR-52. The <br />primary seed mix (Table 2.05-7) is a diverse mix of cool season grasses, forbs, and shrubs. All <br />of the grasses and shrubs are native species; two of the eight forbs are introduced legumes (cicer <br />milkvetch and sanfoin). The introduced species make up less than 7% of the total mix on a seed <br />per square foot basis, and are considered desirable and necessary to provide a component of <br />leguminous forbs. Table 2.05-8 is a list of contingency substitutions, for use on a case-by-case <br />basis, if species in the primary mix are not available. Table 2.05-9 is a shrub mix, to be planted <br />in designated shrub-only planting areas. Prior to 2002 introduced species made up a <br />significantly higher percentage of the primary seed mix, based both on relative number of <br />introduced species, and seeds per square foot in the mix. None of the species proposed for <br />planting are listed as poisonous or noxious plants. <br />Seeding of forbs, shrubs, and grasses will be accomplished primarily by drilling during the fall, <br />with broadcast seeding of wet or steep slopes. Small seeded species such as sagebrush are to be <br />dribbled on the surface using open drill drop tubes, when drill seeding is employed. When <br />necessary, chemical fallowing will be used to eliminate vegetative competition, and fencing will <br />be used to eliminate animal predation. Grazing of reclaimed sites will not be initiated without <br />Division approval. <br />Inclusion of aggressive introduced grass species in the primary seed mix prior to 2002 resulted in <br />large areas dominated by a relatively small number of species, particularly smooth brome and <br />intermediate wheatgrass, with relatively low diversity and low woody plant density. TR-52 seed <br />mix changes approved in April 2002 have resulted in improvements in diversity and woody plant <br />density. With the submittal of Technical Revision 72 Colowyo eliminated all introduced species <br />from their seed mixes with the exception of cicer milkvetch. Currently, Colowyo has two <br />primary seed mixes, targeted for two different reclamation goals. The first seed mix is a <br />grassland seed mix. This seed mix contains grass, forb and shrub seeds chosen based on success <br />and failure rates of 30 years of reclamation at the Colowyo Mine. The grassland mix is a quick <br />establishing mix that will be used for erosion control and grazing on slopes of >10%. The <br />second seed mix is a sagebrush steppe mix. This seed mix also contains grass, forb and shrub <br />seeds but the grass and forb seed quantities have been reduced and the shrub seed quantities have <br />been increased. This mix is targeted at creating areas with high densities of shrubs, with enough <br />grasses and forbs emerging early in the reclamation to control erosion. The sagebrush steppe <br />seed mix will be used on slopes <10%. Colowyo has mapped approximately 900 acres of <br />Proposed Decision and Findings of Compliance 14 September 2009 <br />Permit Renewal 05 Page 58