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Mr. Gregg Squire 3 December 17, 1986 Colorado Mined Land Recl. Division According to Soil Conservation Service recommendations for brush control, shrubs should be thinned when canopy cover exceeds 10 to 15Y„ dependent upon shrub species (USSC, Standards and Specifications Brush Management, 1984). Further, when there is dual use as here, i.e. livestock grazing and wildlife habitat, the SCS recommends managing [he brush in patterns that favor bush livestock and wildlife (hence the 1.6 acre mature shrub clumps). A mature stand of 1,000 shrub stems per acre will result in canopy cover Ear in excess of 15%. Crown diameter (dependent upon the type of shrub) at matu- rity will probably range from 3 to 12 Eeet (based on preliminary data at Trapper Mine). If one conservatively assumes that in a mature stand of moun- tain shrub the average shrub crown diameter is 5 Feet and the spacing of 1,000 stems ('actual plants at maturity) per acre is 6.6 feet, then the canopy cover is 45%.. (Canopy cover as determined from SCS Colorado Range Note ik27, 1987, Proposed Method Eor Determining Percent Canopy Cover of Shrubs, Exhibit No. 3.) Table 2.3-13 of our permit application shows the premine shrub canopy cover for undisturbed range sites A, B, and C within the mine plan area. Range Site A had a premine shrub canopy cover of 64.5%: Range Site B 45.0%, and Range Site C 35.9%. (See the permit application for method of measure- ment.) So the 1000 stem standard would result in approximately the same canopy cover as premine conditions. But, the intent of the approved shrub reestablishment reclamation plan was to end up with a shrub component [hat made optimum use of the reclaimed ran_ve- lands Eor both livestock and wildlife. A standard of 1,000 stems per acre will nut, in the lung term, achieve this goal. in fact, it has the potential to recreate the brush thickets which existed prior to mining, which was agreed during the application review to he a hindrance to optimum use by both live- st~ck and big game. This is supported by Vallentine (.1974) in a study un eastern Arizona pine Forests. He found relative shrub-free areas (46 acres) are appropriate for multiple-use (wildlife, domestic, live stuck, etc.) rangelands. In addltlun, that study showed that deer preferred open areas high in furbs, while elk pre- ferred open grassy areas with brush cover within 800 feet. Thus, given the approved postmining land use uE domestic grazing and wildlife habitat for A and B range sites, the present methods and approved densities Eor shrub reestablishment in [he originally approved application remain appr~- priate. Trapper is willing [o make that standard more explicit, as the Divi- sion requested, by proposing to stale the standard as an overall average of 400 stems per acre. TV VIIe "i. What is the basis for the Div isiun cu impose a shrub standard different from what was originally proposed and approved? cunt.