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• Bond release sampling methodologies for the various vegetation parameters of interest are as follows. <br />Cover. Cover will be measured by the point intercept method. Point intercept transects will be at least <br />25 meters long with a minimum of 50 points taken. Absolute and relative percent cover data will be <br />collected by plant species, plant life form, litter, rock and bare ground. Also, species diversity will be <br />determined from sampled relative cover data. <br />Production. Production data will be determined by the harvest method. Herbaceous production will be <br />collected by clipping the current year's biomass within the vertical projection of randomly located <br />rectangular plots. Selection of plot size and shape will depend on vegetation conditions of the bond <br />release block to be sampled. Production data will be collected by plant life form as applicable. <br />Woody Plant Density. Woody plant stem densities will be measured in randomly located direct count <br />belt transacts which will generally be 2 m by 50 m in size. Larger or smaller belt transacts may by used, <br />however, depending on the conditions of the bond release area to be sampled. All woody plant stems <br />rooted within the direct count transects will be tallied and reported by species. As applicable, two-stage <br />sampling may be used in order to reduce sample variability, which would in turn reduce the number of <br />samples required to meet sample adequacy. <br />Statistical testing for demonstrations of revegetation success for cover, production, and woody plant <br />• density will be conducted for all bond release blocks, except that woody plant density testing will not be <br />required for reclaimed range site C areas. Revegetation success for these parameters will be <br />demonstrated when the parameter population mean for the bond release block is not less than 90 <br />percent of the approved bond release technical standard, at the 90 percent statistical confidence level <br />(alpha error probability = .10, for a one-tailed confidence interval) for two consecutive years. The cover <br />and production component provided by noxious weeds will be deleted from bond release data prior to <br />success comparisons for those parameters. In addition, the allowable relative cover and production <br />contribution of annual and biennial species exceeding 10 percent will be subtracted from the total for <br />each sample observation prior to success comparisons for cover and production. <br />Sample size adequacy testing for cover, production and woody plant density will follow the formulas <br />outlined in Section 4.15.11 of the Regulations of the Colorado Mined Land Reclamation Board for Coal <br />Mining. <br />4-123 <br />