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SaYrar 2.04.10 <br />area corresponds [o an existing powerline road as shown on the Regional Vegetauon Map, (Map 2.04- <br />• M8). Mapping covered much of the present Pemtit area, while sampling was limited to a zone of <br />undisturbed vegetation surrounding the disturbance areas existing at the tune of sampling. Mapping <br />involved the use of color infrared and black and white photos to identify and delineate vegetation <br />types at a scale of 1" = 500' based on vegetation stnrcture and dominant species, with subsequent <br />field reconnaissance to verify or adjust the mapped vegetation community boundaries. Vegetation <br />mapping information is presented on the Regional Vegetation Map, (Map 2.04-M8). Due to <br />similarities in elevation, aspect, and surrounding undisturbed vegetation and the very limited amount <br />of new surface disturbance, the vegetation infom~ation provided by the Baseline Vegetation Inventory <br />u considered to be representative for both existing and proposed mine surface disturbance activities. <br />Vegetation sampling included measurement of cover, production, and woody plant density in July and <br />August of 1981 and calculation of diversity from the cover data. Cover and shrub and tree density <br />data were collected using randomly located 50-meter transecu, with cover measurements at one-meter <br />intervak along each traruect using an optical sight, shrub counu within the area defined by the <br />transect length and a 0.5-meter width (1-meter total width) on each side of the transect line, and tree <br />density counts within the area defined by the transect length and a 2.5-meter width (5-meter total <br />width) on each side of the transect line. Randomly located production plow were used to detemtine <br />production for the two dominant vegetation types identified. Rectangular 1-meter x 4-meter plots <br />were used for the Juniper Woodland type and 1-meter x 2-teeter plots for the Mountain Shrubland <br />type with clipping of the current }eaz's growth and Boning by species for grasses and by type for <br />fortis. <br />Sample adequacy was evaluated using the equation for cone-tailed t-test: with an 80 percent <br />confidence interval and a 10 percent detection limit: <br />Where N,,,;,, u the minimum number of transects <br />s= is the sample variance <br />t'- u the statistical confidence interval (one-tailed w/80 percent confidence) <br />d u the desired detection limit (10 percent) <br />x is the mean sample value <br />Species diversity was calculated for each vegetation con+~*+~~~~ty from the cover data using the formula <br />(Whittaker, 1975): <br />E (n;/N) log (n;/N) <br />Where nt u the absolute value of cover for each species <br />Nis the absolute value of total cover for all species <br />Species identification was based on standard taxonomic references for Colorado (Weber and <br />Johnston, 1979; Nckerson et al., 1976; Beetle, 1970; and Thornton et al., 1974) with confirmation by <br />Dr. William Weber, Colorado State University. <br />Given the dominance and consistency of the sampled vegetation communities for the limited mine <br />surface disturbance areas, subsequent sampling of other surface disturbance areas was not deemed <br />necessary by the DMG. Limited delineation and mapping of potential riparian vegetation and <br />wetlands areas in the vicinity of the Elk Creek Mme surface facilities was condutted by Cedaz Creek <br />Associates 1999 in conjunction with the Noah Fork Coal Leasing EIS. This field investigation <br />resulted in delineation of very limited areas of riparian wetlands vegetation within and in a narrow <br />• band immediately adjacent to the Ells Creek channel. <br />PR04 2.04-103 Revised August 2000 <br />