Laserfiche WebLink
Sample site locations were randomly selected in the office prior to conducting quantitative studies in the field. <br />Random sampling locations were determined using existing topographic maps and a number linear grid scaled at <br />approximately 50 foot intervals. Sampling sites were located by obtaining X and Y coordinates from a random <br />numbers table. <br />Adequacy of sampling was determined periodically during field sampling utilizing the following equation from <br />Sendecor and Cochran (1967): <br />N~;~= t~s~/(dx)r <br />Where: <br />Nam;„ =minimum number of samples needed <br />t =distribution value at a given confidence level <br />sZ =sample variance <br />d = 10% level of accuracy <br />x =sample mean <br />An adequate sample was obtained in each type n,~~ requirement of the above equation with a minimum of 15 samples <br />or a maximum of 50 samples. Using the n,~„ it was shown that one sample was needed to obtain sample adequacy <br />based upon a mean of 58.1, standard deviation of 4.Q and a t=1.282. <br />The sample site is located east of State Highway 13 and is characterized by rather steep slopes (up to 45 percent) with <br />flattened terraces, rock outcrops, old road right-of-ways, and other disturbed areas. Approximately one third of the <br />area is comprised of native sagebrush vegetation primarily close to Highway 13. The sample area is shown <br />graphically on the Vegetation Map (Map 20). The surface of the sampled site is comprised of coal and other spoil <br />materials. Several telephone and power lines traverse the area. A large sediment pond occurs on [he northern end of <br />the sample area. <br />Shrub densities were obtained along a 50 meter transect by counting all individuals rooted within one (1) meter of <br />one side of the transect. Seedlings (less than 5 inches in height) of shrubs were not counted, however, adult shrubs <br />possessing diminutive morphology were counted. <br />Results. Mean vegetative cover was approximately 58 percent in the sampled.site. A summary of vegetation cover <br />information is presented on Table 36, Summary of Disturbed Area Cover and Shrub Density Data - 1983. The <br />vegetation cover 'was comprised primarily of annual grasses (cheatgrass and brome) and perennial fortis <br />(predominantly yellow sweet clover). Bare ground comprised approximately 18 percent of the vegetation cover. <br />Shrub density information was also obtained from the sampled site. Shrub density information is summarized in <br />Table 36, Summary of Disturbed Area Cover and Shrub Density Data - 1983, while specific shrub density data is <br />presented in Table 37, Disturbed Area Shrub Density Data - 1983. Detailed information regarding cover data is <br />presented in Table 38, Disturbed Area Cover Data - 1983. <br />Onty 15 samples were taken which did not meet adequacy requirements, however, this was due to the irregular <br />distribution of shrubs and it was decided sample adequacy (69 samples) would not provide more information. It <br />should be understood that shrub density is being offered for informational purposes as there are no requirements for <br />measuring this parameter. <br />Overland Conveyor Area <br />The overland conveyor from the No. SA portal to the No. 5 portal traverses three (3) vegetation communities. These <br />are 1) sagebrush, 2) riparian, and 3) disturbed. The sagebrush community is found on the west facing slopes east of <br />Highway 13 and downslope from the disturbed area. The soil associated with this vegetation community is the <br />Permit Renewal No. 4 2.04-32 Revised 3/5/03 <br />