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When the reclaimed area has entered the final two years of the responsibility period (assumed to be <br />2005 and 2006), mean cover, production, and woody plant density values and associated variances will <br />be determined for both the herbaceous and shrub components as appropriate. These pa2meters will be <br />determined using point-intercept along line-transects for ground cover and harvest methods for <br />production from both the revegetated communities and the newly established reference areas. Sampling <br />in these areas will continue until: 1) a maximum of 35 samples have been collected or 2) sampling <br />adequacy (nm;n) has been attained in accordance with the promulgated Coloredo guideline (April 18, <br />1995) formula for sample adequacy when statistical testing is not required, as folows: <br />nmin = (t 2g 2) ! (0.1 S )2 <br />Where: n =the number of actual samples collected with a minimum of 15 in each unit; <br />t =the value from the t distribution for 90% confidence with n-1 degrees of freedom; <br />s 2 =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, for an unexpected reason statistical testing is required, the sampling adequacy equation for this <br />circumstance ("Hypothesis Testing Based Sample Size Formula for Reclaimed Areas" as detailed in the <br />Colorado Guidelines -page 20) should be utilized for both reclaimed and reference areas to increase the <br />statistical power of the test This formula appears as follows: <br /> <br />where: n =the number of actual samples collected with a minimum of 15 in each unit; <br />to =the value from the single tailed t distribution for a = 0.1 with n-1 degrees of freedom; <br />to =the value from the single tailed t distribution for a = 0.25 with n-i degrees of freedom; <br />s Z the variance of the estimate as calculated from the initial samples; <br />Q = 90% of the reference area sample mean x or 90% of the technipl standard <br />x =the mean of the estimate as calculated from the initial samples. <br />Once an adequate sample (where appropriate) has been collected for each revegetated community <br />and reference area for both cover and production, the means and variances (x and s2) will be utilized <br />for testing revegetation success or failure during that particular year, if testing is necessary. Testing is <br />not necessary if the revegetated area's mean is equal to or greater than 90% of the reference area's <br />~i~r~ e~~ ~~~c¢s$~ -wc. Page 9 Blue Ribbon Mtne - Revegelatlon Evaluatlon <br />