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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 25 <br />meters long with a minimum of 50 points taken. Absolute and relative percent cover data will be collected <br />by plant species, plant life form, litter, rock and bare ground. Also, soecies diversity will be determined <br />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 wtthin 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 denstties will be measured in randomly located direct count belt <br />transects which will generally be 2 m by 50 m in size. Larger or smaller belt transects may by used, <br />however, depending on the condttions of the bond release area to be sampled. All woody plant stems <br />rooted wtthin 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 tum 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 />densely 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 far the bond release block is not less than 90 percent <br />of the approved bond release technical standard, at the 90 percent statistical confidence level (alpha <br />error probability = .10, for cone-tailed confidence interval) for two consecutive years. The cover and <br />production component provided by noxious weeds will be deleted from bond release data prior to success <br />comparisons for those parameters. In addition, the allowable relative cover and production contribution of <br />annual and biennial species exceeding 10 percent will be subtracted from the total for each sample <br />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 CDMG's GUIDELINE REGARDING SELECTED COAL MINE BOND RELEASE ISSUES, <br />dated April 18, 1995. The hypothesis testing formula will be used when the sample mean is less than the <br />standard. When the sample mean is greater than the standard, the sample size formula, which excludes <br />the beta error probability, will be employed. WAh regard tc woody plant denstty sample adequacy testing, <br />it is generally acknowledged by CDMG that, due to the inherent variability of stem density data, a more <br />appropriate formula is needed. At such time that a new formula is approved, Trapper will revise this <br />section to include tt as part of our statistical sampling methodology. <br />• <br />4-123 <br />Revision:~- <br />Approved: 2~_ 8~yfi- <br />