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RULE 2 PERMITS <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 />The lower grassland reference area is a small area (1.23 acres) along the western study area boundary and <br />immediately adjacent to an improved pasture belonging to an adjoining landowner. This was the only <br />"sizeable" area of gassland in the vicinity of the study area that could be used for this purpose. However, <br />this area was not without difficulties. Because of proximity to the improved pasture, many of the <br />improved pasture grass species (especially intermediate wheatgrass) have heavily invaded thereby <br />artificially increasing the cover and production values of the reference area. These elevated values would <br />preclude statistical validation of this single area as a representative revegetation performance target. The <br />second reference location exhibits limited cover and production values, and as such precludes statistical <br />validation as a representative revegetation performance target (because of the depressed values). <br />However, the average values from these two areas combined do provide a statistically valid revegetation <br />performance target. <br />With regazd to the lower (fenceline) reference area, average ground cover of vegetation was 81.8% with <br />0% rock, 15.4% litter, and only 2.8% bare ground exposure. Dominant species included: intermediate <br />wheatgrass (Agropyron intermedium), tailcup lupine, and bluegrass. The number of perennial herbaceous <br />species exhibiting between 3% and 50% relative cover (composition) was determined to be 2 gasses and <br />1 forb. Current annual herbaceous production within the lower grassland reference area was determined <br />to be 3,038 pounds per acre with 70% due to perennial grasses and 30% due to perennial forbs. Only a <br />fraction of a percent was due to annual species. Woody plant density based on the total count of plants <br />within the reference area was 644 plants per acre with dominance by mountain big sagebrush and rubber <br />rabbitbrush. <br />• With regard to the upper (ridgeline) reference area, average ground cover of vegetation was 38.13% with <br />36.27% rock, 8.73% litter, and 16.87% bare ground exposure. Dominant species included: thrifty <br />goldenweed (Stenotus armerioides), Montana wheatgrass (Agropyron albicons), Sandberg bluegrass (Poa <br />secunda), black sagebrush (Artemisia nova), prairie junegrass (Koeleria macrantha), needle and thread <br />(Stipa comata), and beardless bluebunch wheatgrass (Agropyron spicatum inerme). The number of <br />perennial herbaceous species exhibiting between 3% and 50% relative cover (composition) was <br />determined to be 5 grasses and 1 forb. Current annual herbaceous production within the upper grassland <br />reference area was determined to be 405 pounds per acre with 34% due to perennial grasses and 64% due <br />to perennial forbs. The remaining 2% was due to annual species. Woody plant density based on the total <br />count of plants within the 1.01 acre reference area was 257 plants per acre with dominance by black <br />sagebrush and serviceberry (Amelanchier alnifolia). <br />As previously indicated, neither of these reference areas could be statistically validated individually as <br />they differed too significantly from the remaining grassland type within the study area. The lower area <br />exhibited greater cover and production than the primary study area type, whereas the upper area exhibited <br />reduced cover and production values in compazison to the study area type. Field judgment dictated that <br />the best course of action was to sample both areas to statistical adequacy, recombine the two data sets to <br />provide a single set of testing parameters, and proceed with the t-test of the means using the pooled data. <br />This strategy proved successful as the combined data set passed both cover and production validation <br />testing (Table 2.04.10-21). For ground cover the calculated t statistic was 1.6582 that compared <br />favorably (less than) the Tabular t statistic of 2.0167. Similarly for production the calculated t statistic <br />was 0.1387 that compared favorably (less than) the Tabular t statistic of 1.9908. Although statistical <br />testing for woody plant density is not necessary (because performance standards have been set), this <br />. vaziable compared favorably as well. The grassland community exhibited a value of 509 plants per acre <br />whereas the pooled data from the two reference sites averaged 451 plants per acre or about 90% of the <br />study area grassland value. <br />South 2aylor/Lower Wilson -Rule2, Page 75 Revision Date: 1131/07 <br />Revision No.: PR-02 <br />