Laserfiche WebLink
• <br />E <br />exceeded the cover on the rangeland reference area (19.7%). Cover in the reclaimed <br />rangeland community is successful. <br />Production data was collected in 2005 using 0.1 meter square plots. Six plots were <br />placed along each of the fifteen 25 m transects. The 2005 production data for the AVF <br />reclaimed and reference areas did achieve sample adequacy based on the appropriate <br />sample size adequacy formula, and quadrats were appropriately treated as <br />subsamples. The reclaimed sample mean (1822 Ibs/acre) exceeded 90% of the <br />reference area sample mean (1816 Ibs/acre). A statistically valid demonstration of <br />success was made for the 2005 pasture land production data. <br />In contrast to the AVF area, statistical sample adequacy was not demonstrated for the <br />2005 rangeland production data, in either the reference area or the reclaimed area. <br />Due to the sample adequacy problem, Greystone chose to define individual quadrats as <br />sample observations, even though they were arranged as groups of 6 quadrats along <br />15 transects. Based on this terminology, 90 sample observations were tallied, rather <br />than 15. Still, sample adequacy was not achieved in either the reference area or the <br />reclaimed area. <br />It is evident from the data that 2005 rangeland reclaimed area production exceeded the <br />reference area production by a wide margin. The 90% upper confidence limit on the <br />reference area mean is 44.4 grams/square meter, while the 90% lower confidence limit <br />on the reclaimed area mean is 130.9 grams per square meter (unadjusted data). The <br />confidence intervals do not overlap, and are separated by a wide margin. A two sample <br />reverse null t-test would support the same conclusion, that the reclaimed area <br />production exceeds the reference area production. <br />In the final bond release report, the Division is requesting that two separate West <br />demonstrations be presented for the 2005 rangeland production data. The first test <br />should be a two sample reverse null t-test, based on the sample size of 90 in the <br />reclaimed area and reference area (each uadrat treated as an independent <br />observation). The second test should be a two sample reverse null t-test, based on a <br />sample size of 15 in the reclaimed area and reference area (each transect treated as an <br />independent observation). Both tests should be based on "corrected" quadrat data <br />(undesirable component removed from the data from each quadrat prior to calculation of <br />sample statistics). If both tests conclude that reclaimed area production exceeds <br />reference area production, I believe we could accept the data as a valid demonstration <br />of success (recognizing that the regulations specifying specific sample size <br />requirements and treatment of transect quadrats as subsamples were not in effect alt <br />the time of sampling). <br />The species diversity standard was achieved in the 2005 reclaimed rangeland as <br />documented in Table A-6. Contributing cool season grasses were smooth brome, <br />western wheatgrass and slender wheatgrass. Warm season grasses were blue grama <br />and sideoats grama. The forb was alfalfa.