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A. The Division proposes to approve the use of one introduced species, weeping alkali <br />grass (Puccinellia distans), in the reclamation seed mix. The species is desirable and necessary to <br />achieve the approved post -mining land use, is not poisonous or noxious, and comprises less than <br />10% of the seeding rate on a seeds/square ft. basis, for each planting area (4.15.2(3)). <br />B. The Division proposes to approve the use of certified noxious weed -free, grass hay or <br />straw mulch as a means to meet soil stabilization requirements. The mulch will be crimped into the <br />soil on drill seeded sites or anchored with tackifier on broadcast seeded sites. If broadcast or hydro <br />seeding is employed, the soil surface will be extensively roughened prior to seeding by means of <br />track -hoe gouging or contour ripping (4.15.4). <br />C. Methods to measure vegetation cover, herbaceous production, species diversity, and <br />woody plant density are discussed in Section 3.4.9 of the application. These techniques include point <br />intercept for cover sampling, quadrat clipping for herbaceous production estimates, and quadrat stem <br />counts for woody plant density estimates. The Division proposes to approve of these techniques <br />(4.15.7(1)). The sampling techniques and statistical methods to be used in demonstrations of <br />revegetation success are in conformance with Rule 4.15.11. <br />D. Comparisons between reclaimed and undisturbed areas, in order to demonstrate that <br />success criteria of 4.15.8, 4.15.9, or 4.15. 10 have been met, will be based on the following: <br />Reference areas have been established for each designated vegetation type, and were <br />originally proposed to be used for comparisons of both vegetation cover and herbaceous production <br />for the affected types (juniper woodland, shadscale shrubland, and greasewood shrubland). The <br />reference areas have been approved for vegetation cover success comparisons. However, because <br />sample adequacy requirements were not met for production within either the reference areas or <br />affected areas for these types, use of reference areas for production comparisons was not approved. <br />Because the combined affected area herbaceous production data for McClave Canyon and the <br />adjacent Munger Canyon permit areas did meet sample adequacy, within each vegetation type, it <br />was determined that the combined affected area production data would be used as the success <br />standard for each of the affected vegetation types, pursuant to Rule 4.15.7(2)(d)(vi) [April 16, 1985 <br />Findings Document]. The herbaceous production success standards based on combining of the data <br />within vegetation types for both mines are as follows: <br />Greasewood Shrubland sample mean: 766 lb/ac. <br />Standard (90% of mean): 690 lb/ac. <br />Shadscale Shrubland sample mean: 661 lb/ac. <br />Standard (90% of mean): 595 lb/ac. <br />Juniper Woodland sample mean: 389 lb/ac. <br />Standard (90% of mean): 3501b/ac. <br />The diversity standard is specified on page 3-17, and requires that a minimum of three <br />perennial species shall each provide a minimum of 3% relative cover. At least two of these species <br />shall be cool season perennial grasses. No individual species shall represent more than 60% relative <br />cover. This standard was established via by RN -04, which amended the previous standard which <br />mentioned perennial forbs and warm season grasses as counting toward the diversity standard but <br />identified no minimum relative cover level for any particular life form. Neither warm season grasses <br />nor perennial forbs were significant components of the affected vegetation types. The relatively <br />