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272 <br /> X1 - X2 I <br /> in <br /> 22 <br /> where x, = mean cover or production for the affected area <br /> X2 = mean cover orlproduction for the reference area <br /> It t = a t-statistic value, which varies depending on desired <br /> level of confidence and sampling size <br /> Poa(e� <br /> s; = theeariance bf cover and production for the affected area <br /> s2 = they arliahce pf cover and production for the reference area <br /> I <br /> n, = sample size in the affected area <br /> n2 = sample size iIn the reference area <br /> When Ix, - X21 is less than or equal to the other calculated value, the <br /> affected area and reference area are considered comparable for the purpose <br /> of evaluating reclamation success. <br /> Reference Area Sampling Dpesign <br /> All sample sites will bel located by a random process. The southwestern <br /> corner of the reference area will serve as the intersection with an x <br /> and y coordinate system. positive coordinates will be produced by a <br /> random number generator. The exact sample point will then be paced off <br /> by the field ecologist. <br /> Collection and Analysis of Cover Data <br /> Cover will be estimated using a point-intercept method along randomly <br /> located and oriented tr nsects (Mueller-Dombois and Ellenberg 1974) . <br /> Fifty points will be saZ led along the 50 meter length transects. <br /> Sample points will be or)e meter apart. Each transect will represent <br /> one sample. <br /> The .siting device will qe mounted on an adjustable tripod to facilitate <br /> vertical orientation and point stabilization. Fine cross hairs will be <br /> used in the siting devi e to provide optimum point definition. At each <br /> sample point, the first hit ( interception) along a vertical line will be <br /> recorded as vegetation (by species) , rock , litter, or soil . Vegetation <br /> intercepted below first 'hits will be recorded as a second and third hit. <br /> Sample adequacy will be calculated on total herbaceous vegetation cover. <br /> Sample adequacy require ents for affected area cover data will be cal- <br /> culated using the formu a <br /> -2- <br />