Laserfiche WebLink
RULE 2 PERMITS <br /> 8>$"hte:44 {: .q4; ,NN$:iSF .d? k^.:`;Z.4"v";`.A$4/4,4° V4,w.4,',64/*".t.4444:J g4,,';H. *,,,,1041T44168tort4NtWiWrOUP00�l"'} :srory +.• <br /> species are designated noxious weeds("B"List taxa on the Colorado State List)with several others (e.g., <br /> cheatgrass) classified as invasive weed species. Identified noxious weeds include musk thistle (Carduus <br /> nutans), Canada thistle(Cirsium arvense),and houndstongue(Cynoglossum officinale). <br /> Specific - Detailed vegetation mapping and quantitative data collection occurred by performing baseline <br /> vegetation surveys (or supplemental surveys) within the study area of the Lower Wilson Mine Area. <br /> Emphasis was placed on the disturbed area for quantitative efforts. Six native vegetation communities <br /> and two land use types were identified from this area as follows: <br /> Mountain Shrub Juniper Scrub <br /> Sagebrush Bottomland <br /> Aspen Woodland Cropland(land use) <br /> Grassland Stock tank(land use) <br /> As previously discussed, only the grassland community was completely sampled with baseline surveys <br /> (ground cover, production, and woody plant density) while the remaining communities received <br /> supplemental ground cover sampling. In this regard, grassland was the only vegetation type requiring <br /> establishment of a reference area to facilitate development of performance criteria. Rationale for this <br /> strategy was that existing data and reference areas for Mountain Shrub, Sagebrush, and Aspen <br /> communities would be sufficient for this permit revision effort (see existing Colowyo permit and Table <br /> 2.04.10-10). <br /> As previously indicated, the juxtaposition / distribution of Study Area vegetation communities, sample <br /> collection locations, and reference areas are presented on Map 4. A summary of the average ground <br /> cover based on 2005 data is presented on Table 2.04.10-11 and Figure 2.04.10-3. Similarly, a summary <br /> of the relative cover (composition) based on 2005 data is presented on Table 2.04.10-12 and Figure <br /> 2.04.10-4. Raw ground cover and production data for the grassland community and reference areas are <br /> presented on Tables 2.04.10-13 through 2.04.10-18 with a summary of production data presented on <br /> Table 2.04.10-19 and Figure 2.04.10-5. The raw data for grassland woody plant density are presented on <br /> Table 2.04.10-20 and Figure 2.04.10-6. The principal parameters for the t-test of the means utilized to <br /> validate the grassland reference areas are presented on Table 2.04.10-21. Finally, the raw ground cover <br /> data collected as supplementary information for the five non-grassland communities are presented on <br /> Tables 2.04.10-22 through 2.04.10-26. <br /> Grassland-As indicated on Map 4,the grassland community within the Study Area occupies 16.97 acres <br /> and occurs in six locations. The two grassland reference sites are located against the west Study Area <br /> boundary(1.23 acres)and on the ridgeline(1.01 acres). <br /> A total of 31 species were observed within the grassland community while the lower and upper reference <br /> areas exhibited 29 and 42 taxa, respectively. Average ground cover of vegetation within the study area <br /> was 69.93% with 0% rock, 21.07% litter, and 9.0% bare ground exposure. Dominant species included: <br /> bluegrass (Poa agasizensis), thickspike wheatgrass (Agropyron dasystachyum), Western wheatgrass <br /> (Agropyron smithii), tailcup lupine (Lupinus caudatus), slender wheatgrass (Agropyron trachycaulum), <br /> groundsmoke (Gayophytum ramosissimum), and mountain big sagebrush (Artemisia tridentata ssp. <br /> vaseyana). The number of perennial herbaceous species exhibiting between 3% and 50% relative cover <br /> (composition) was determined to be 4 grasses and 1 forb. Current annual herbaceous production within <br /> the Study Area's grassland community was determined to be 1,754 pounds per acre with 83% due to <br /> perennial grasses and 15%due to perennial forbs. The remaining 2% was due to annual species. Woody <br /> plant density based on the total count of plants within a 0.46-acre macroplot was 509 plants per acre with <br /> dominance by mountain big sagebrush and rubber rabbitbrush(Chrysothamnus nauseosus). <br /> South Taylor/Lower Wilson—Rule 2,Page 52 Revision Date: 12/20/19 <br /> Revision No.: TR-135 <br />