Laserfiche WebLink
RULE 2 PERMITS <br /> <br />South Taylor – Rule 2, Page 41 Revision Date: 7/21/25 <br /> Revision No.: MR-267 <br />pursuant to Section 4.15.7(3)(b)(iii). Colowyo has determined to use this reference area in this manner <br />instead of the “Harner established” South Taylor Sagebrush Reference Area (ST-SRA) for eight reasons <br />as follows. <br />First, the C-SRA is readily accessible (located near the Administration Building) and should remain <br />accessible during the life-of-mining. <br />Second, the C-SRA has been measured more frequently over the past several years and therefore, presents <br />a more extensive historic data-base. C-SRA data indicated for the third point below come from the 2005 <br />sampling effort from the C-SRA and new tables providing these data have been provided as Tables <br />2.04.10-28 through 2.04.10-32. <br />Third, an analysis of data indicates that the C-SRA more closely resembles the South Taylor Study Area <br />than the ST-SRA with respect to dominant species and lifeform composition. Big sagebrush (Artemisia <br />tridentata) comprises 28% and 27% of the C-SRA and South Taylor Study Area’s vegetation <br />composition, respectively, while comprising only 13% (less than half) of the ST-SRA vegetation. To the <br />contrary, deciduous shrubs comprise twice (29%) of the ST-SRA vegetative composition but only 17% <br />and 5% of the Study Area and C-SRA’s composition. And finally, perennial grasses comprise only 24% <br />of the ST-SRA vegetative composition while comprising 32% and 40% of the Study Area and C-SRA’s <br />composition. In this regard, the C-SRA would be considered a better ecological target for reclamation <br />attempting to re-establish sage and grassland communities. <br />Fourth, (and of elevated significance) it appears the ST-SRA is located in an ecotone between the more <br />mesic mountain shrub community type and the mesic sagebrush community type based on composition <br />data, narrative descriptions, and photographs presented by Harner in his 1984 report. Harner describes <br />this area as the sagebrush-snowberry phase, which exhibits deeper more productive soils than the <br />sagebrush - wheatgrass phase more typical of most Colowyo disturbances. The ST-SRA is surrounded <br />and being invaded by mesic mountain shrub that will most likely continue to expand into, and replace, the <br />sagebrush community as succession progresses. This observation is also verified by review of 2005 aerial <br />imagery of the communities within and adjacent to the ST-SRA. Over the 21 years since the original <br />mapping, the area that could be segregated as sagebrush has substantially diminished in areal extent. To <br />the contrary, the C-SRA is located in a large expanse of the sagebrush – wheatgrass phase with occasional <br />patches of the mountain shrub community in draws and depressions and the more shallow-soiled juniper <br />scrub community in rock outcrop areas. Very few compositional changes in the dominant taxa are <br />expected in this area as succession progresses. Furthermore, this sagebrush-wheatgrass phase of the sage <br />community is a more appropriate ecological comparator given the similarity of this area’s underlying soil <br />profile with the constructed growth media profile of Colowyo’s reclaimed land. <br />Fifth, based on statistical testing per current Division guidelines, the ST-SRA is not comparable to the <br />South Taylor Study Area for either cover or production (see Table 2.04.10-27) but is eligible as a <br />reference area only because values are higher than those found in the study area. The sampling adequacy <br />and equivalency procedures used by Harner in 1984 were more liberal for such evaluations. <br />Sixth, a review of data presented on Figures 2.04.10 – 7 and 8 indicated that Harner’s 1984 data for the <br />ST-SRA is substantially elevated over all other comparable sagebrush data sets from the area, but most <br />importantly, the values are 25% and 50% higher than the surrounding South Taylor Study Area during the <br />same year for cover and production, respectively. Some of this difference with data sets from other years <br />can be explained by an analysis of precipitation. However, the strong differences between the ST-SRA <br />and the study area reduce the defensibility of this reference area as an appropriate comparator. <br />Seventh, the sagebrush-grassland ecotype is the main ecological community that will be targeted by