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RULE 2 PERMITS <br />• All production samples were returned to the lab for drying and weighing. Drying occurred at 105 degrees <br />Celsius until a stable weight was achieved (24 hours). Samples were then re-weighed to the neazest 0.1 <br />gram. Wet weights determined in the field were used to facilitate the collection of an adequate sample <br />where necessary. <br />Determination of Woody Plant Density -Documentation of woody plant densities in the grassland type <br />(and associated reference areas) involved a total count of the shrubs within the entire area subject to <br />sampling, or within large macroplots that occupy a substantial portion of the area subject to sampling. <br />Implementation of this enumeration technique involved circumscribing the boundaries of the target <br />polygon with hip chain thread and asub-meter GPS unit. Once a target polygon was circumscribed, a <br />team of two or more biologists walking shoulder to shoulder traversed the area enumerating each plant by <br />species. The person farthest inside the line of observers trails hip chain thread to mark their path to <br />prevent missing or double counting specimens on subsequent passes. The distance between observers is <br />usually 15 feet or less depending on the height of grasses and the presence of low growing taxa. Constant <br />communication among crew members precludes double counting or missing of plants located along the <br />margins of observed paths. <br />Sample Adequacy Determination -Sampling within the grassland community type and reference areas for <br />ground cover and production was conducted to a minimum of 20 samples. From these initial samples, a <br />mean and standard deviation for each variable was calculated. Where statistical testing is required, <br />collection of an adequate sample (nm;,,) is typically necessary to insure reliable estimates of the population <br />(e.g., estimates to within 10% of the true mean (µ) with 90% confidence). Where statistical testing is not <br />required (10 ground cover transects in each of the other dominant communities) sample adequacy was <br />• calculated for informational purposes only. The Cochran formula below was utilized in accordance with <br />directives in Colorado's guidelines (1988). When the inequality (nm;~ < n) is true, sampling can be <br />considered to be adequate, and nm1° is determined as follows: <br />nmin = (t2s2) / (0.1 x <br />Where: n =the number of actual samples collected with a minimum of 20 in each unit; <br />t =the value from the t distribution for 90% confidence with n-1 degrees of freedom; <br />s z =the variance of the estimate as calculated from the initial samples; <br />x= the mean of the estimate as calculated from the initial samples. <br />If the initial minimum number of samples in each area did not provide a suitable estimate of the mean <br />(i.e., the inequality was false), additional samples were collected until the inequality (nm1° < n) became <br />true. This latter circumstance was necessary for collection of an adequate sample for the variable of <br />production within the grassland community area. <br />Detailed Vegetation Information <br />General - As indicated above six native floral assemblages (communiTy Types) and two land use types <br />were delineated within the vegetation study area. Boundaries between plant communities and land use <br />types were delineated from aerial imagery and were confirmed or adjusted through on the ground <br />verification techniques. In certain instances the original delineations from the existing Colowyo permit <br />were significantly modified and in other circumstances little modification resulted. Results of these <br />• delineations are presented on Map 4B. Acreages and relative distribution for each community /land use <br />type within the vegetation study area are presented in Table 2.04.10-8. <br />South TaylodL.ower Wilson -Rule 2, Page 73 Revision Date: 1/31 /07 <br />Revision No.: PR-02 <br />