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MEMO <br />Fifteen transects per sampling unit were initially conducted prior to evaluation of sample adequacy. <br />Sample adequacy for vegetative cover and herbaceous biomass production within each sampling unit was <br />determined using the Snedecor-Cochran sample adequacy formula (Equation 3). <br />t2s2 <br />N.in = (d) 2 <br />Where: <br />N min = the minimum number of transects or quadrats needed, <br />(3) t = the a =. 10 t -table value for a single -tailed t-test with n-1 degrees of freedom, <br />S2 = the sample variance, <br />.1(level of precision for estimate of the mean to be within 10 percent of the actual mean), and, <br />X = sample mean <br />Vegetative cover data collected along each transect was used to determine sample size adequacy. <br />Sample size adequacy for vegetative cover was reached in both the Rangeland Reclaimed Area and the <br />Rangeland Reference Area with fifteen transects in each. Sample size adequacy for production was <br />reached in each of the two areas with thirty transects. <br />RESULTS <br />Vegetative Cover <br />Initial results from the sampling event show that mean absolute vegetation cover is higher on the <br />Rangeland Reference Area (44.85%) than on the Rangeland Reclaimed Area (26.40%). However, before <br />evaluating if the success standard is met, the undesirable species component must be removed. The <br />Bond Release Regulations state that noxious weeds on either the state or county list should be removed <br />prior to comparing to a success standard. Noxious weed occurrence was low on both the reference and <br />reclaimed sites, with 8 total hits on noxious weeds, all of which were Convolvulus arvensis individuals <br />located in the reclaimed site. Non -herbaceous cover was also removed prior to quantifying cover <br />estimates, resulting in a significant decrease in overall cover in the reference site. There were no hits on <br />shrubs in the reclaimed site, but a total of 59 hits on shrubs in the reference site, representing 17.6% of <br />total vegetation cover in this site. <br />arcadis.com Page: <br />3/6 <br />