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Golden Eagle Mine Phase III Revegetation Findings <br />Page 3 <br />It is evident from the data that 2005 rangeland reclaimed area production exceeded the reference <br />area production by a wide margin. In the final bond release report, the operator presented two <br />separate t-test demonstrations for the 2005 rangeland production data. The first test was a two <br />sample reverse null t-test, based on the sample size of 90 in the reclaimed area and reference area <br />(each quadrat treated as an independent observation). The second test was a two sample reverse <br />null t-test, based on a sample size of 15 in the reclaimed area and reference area (each transect <br />treated as an independent observation). Both tests are based on "corrected" quadrat data <br />(undesirable component removed from the data from each quadrat prior to calculation of sample <br />statistics). Both tests conclude that the reclaimed area production exceeds the reference area <br />production; therefore, the Division accepts the data as a valid demonstration of success. <br />The species diversity standard was achieved in the 2005 reclaimed rangeland as documented in <br />Table A-6. Contributing cool season grasses were smooth brome, western wheatgrass and <br />slender wheatgrass. Warm season grasses were blue grama and sideoats grama. The forb was <br />alfalfa. <br />Woody plants did not exceed 5% cover in the reclaimed areas. <br />2006 Data <br />In 2006 cover data was collected using the same methods as in 2005. Sample adequacy for <br />vegetative cover was achieved in all four sampling units. Vegetative cover on the pastureland <br />reclaimed area (20.9%) exceeded the cover on the pastureland reference area (19.5%). The <br />reclaimed rangeland cover (14.5%) exceeded the cover on the rangeland reference area (12.8%). <br />Vegetative cover in both reclaimed communities is successful. <br />Production data was collected using thirty randomly located 0.5 m2 plots. Sample adequacy was <br />not achieved using the standard formula for any of the four sampling units. As allowed by Rule <br />4.15.11 (2) (c) a reverse null approach was used. In both cases, the null hypothesis of equality <br />was rejected; the alternative hypothesis (reference area mean less than reclaim area mean) was <br />accepted. This was a statistical confirmation of what was intuitively obvious from the data. The <br />t-tests demonstrated that the reclaimed area means in both the pastureland and the rangelands <br />exceed the respective reference area means at the 90% level of statistical confidence, pursuant to <br />Rule 4.15.11(2)(c). Production is considered successful for the reclaimed pasture and the <br />reclaimed rangeland. <br />The species diversity standard for the reclaimed rangeland was achieved in 2006 as documented <br />in Table A-7. Contributing cool season grasses were smooth brome, western wheatgrass and <br />slender wheatgrass. Warm season grasses were blue grama and little bluestem. The forb was <br />alfalfa. <br />Woody plants did not exceed 5% cover in the reclaimed areas.