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• 2.2 Determination of Ground Cover <br />Ground cover at each sample point was determined utilizing the point- intercept methodology as <br />illustrated on Exhibit 1. As indicated in this figure, Cedar Creek utilizes state -of- the -art instrumentation it <br />has pioneered to facilitate much more rapid and accurate collection of data. A transect of 10 meters <br />length was extended in the direction of the next sampling location from the flagged center of each <br />systematically located sample point. At each one -meter interval along the transect, a "laser point bar" <br />was situated parallel to, and approximately 4.5 feet vertically above the ground surface. A set of 10 <br />readings was recorded as to hits on vegetation (by species), litter, rock ( >2mm), or bare soil. Hits were <br />determined at each meter interval by activating a battery of 10 low- energy specialized lasers ** situated <br />along the bar at 10 centimeter intervals and recording the variable intercepted by each of the vertically <br />projected narrow (0.02 focused beams (see Exhibit 1). In this manner, a total of 100 intercepts per <br />transect were recorded resulting in 1 percent cover per intercept. (Second hits on understory vegetation <br />were not collected owing to the managerial nature of collected data.) All reclaimed area plants as well as <br />reference area plants (including both herbaceous and shrub strata) were subject to sampling. This <br />methodology and instrumentation facilitates the collection of the most unbiased, repeatable, and precise <br />ground cover data possible. <br />is 2.3 Sample Adequacy Determination <br />Sampling of the individual units was restricted to 20 samples for the reclaimed area (10 for the <br />adjacent native area and 5 for each of the 4 segregate reference areas) for cover due to the managerial <br />nature of collected data. However, for informational purposes, sampling adequacy (n has been <br />calculated for each variable in each sampling unit in accordance with the Colorado guideline (April 18, <br />1995) formula for sample adequacy when statistical testing is not required, as follows: <br />nmin = (t252) / (0 <br />Where: n = the number of actual samples collected with a minimum of 5 in each unit; <br />t = the 1- tailed value from the t distribution for 90% confidence with n -1 degrees of <br />freedom; <br />S 2 - the variance of the estimate as calculated from the initial samples; <br />z = the mean of the estimate as calculated from the initial samples. <br />• ** Lasers utilized for this instrument are state -of- the -art and of specialized design to emit a unique electro- magnetic <br />wavelength visible under full sunlight, a condition previously not possible with portable low- energy lasers. <br />CEDAR CREEK ASSOCIATES, Inc. Page 4 Hamilton Mine - Revegetation Evaluation - 2009 <br />