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multiplying the total number of bales counted in a field by the average adjusted bale weight <br />and dividing by the size of the field in acres. Additionally, clipped plots in similar irrigated <br />pastures were used for comparison. <br />4.12 Woody Plant Densities - 1999 Woody plant densities were measured in the sagebrush <br />types, dryland pasture reference area, and willow component of the swale /drainage type using <br />belt transects. All trees and shrubs were included in the counts as outlined in CDMG <br />"Guidelines for Compliance with Land Use and Vegetation Requirements for Coal Mining ". A <br />species was counted for density if it was rooted within the belt. For all species except willow <br />stems were traced back to their origin and counted as one plant. For example, a sagebrush <br />plant that had 4 stems emanating from a central point was counted as one plant/stem. A 3 ft. x <br />100 ft. belt, originating at the randomly - located sample point and extending in a random <br />direction, was used in the sagebrush type and dry land reference area. A randomly - located 1 <br />square meter sampling frame was used for stem counts in the willow component of the <br />swale /drainage. All willow stems emanating from the ground were counted as it was <br />impossible to determine if any one stem belonged to any one plant. Fifteen samples were <br />collected in this manner. <br />4.13 Sample Adequacy 1987 and 1999 The following formula was used to determine the <br />adequacy of the quantitative cover, production, and woody density samples in the New Horizon <br />2 studies: <br />Nmin = (st)2 /(dx)2 <br />where, <br />Nmin = minimum sample size <br />s = sample standard deviation <br />t = two- tailed t -value at the 90 percent confidence interval <br />(alpha = 0.10) with infinite degrees of freedom (t = 1.645) <br />d = desired level of reduction about the sample mean (0.10) <br />x = sample mean <br />In all cases, sampling was continued until the minimum sample adequacy requirements were <br />exceeded, or the prescribed maximum number of observations were collected. Maximum <br />August 2013 (PR 08) 2.04.10 -25 <br />