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where: <br />min <br />sample mean <br />2.4 STATISTICAL ANALYSIS <br />(t) (s) <br />(d Xbar)2 <br />nmin = minimum sample size <br />s = sample standard deviation <br />t = the Student's t distribution value at the 90% level (one- sided) <br />d = percent acceptable deviation from the mean (10 %) <br />Xbar = <br />Statistical analysis for the revegetation success criterion of total vegetation cover is required <br />if the value of the sample mean from the reclaimed area is less than 90 percent of the value of <br />the final revegetation success criteria for total vegetation cover or total herbaceous prod- <br />uction. <br />Sampling revealed that the mean total vegetation cover for the Phase III eligible sampling <br />units was greater than that of the final revegetation cover success standard value; therefore no <br />statistical analysis was required. <br />2.5 SPECIES IDENTIFICATION AND VERIFICATION <br />Species identification was accomplished in the field through the use of plant identification <br />keys (Harrington, 1954, Weber, 1990; Whitson, 1987; Zimdahl, 1990, Stubbendieck, et al, <br />1995). In cases where plant identification was inconclusive in the field, voucher specimens <br />were pressed for lab identification. <br />3.0 RESULTS <br />3.1 QUANTITATIVE EVALUATION: RECLAMATION AREAS <br />3.1.1 PHASE III ELIGIBLE RECLAMATION AREAS <br />The 1998 reclamation areas sampled this year encompass 17.64 acres of reclamation in five <br />areas within the Keenesburg Mine permit area. The areas include Reclamation Area 2, an <br />area immediately west of the dugout, Reclamation Areas 7 and 10, two areas south and east <br />of the central reclaimed mining area, and Reclamation Areas 15 and 16, located north and <br />west of the former A pit and bordered on the west and south by undisturbed range. <br />Vegetation cover transects and herbaceous production quadrats were distributed within the <br />five areas based on size. The 1998 reclamation areas range from flat (Reclamation Areas 2, <br />7) to north and south facing (Reclamation Areas 15, 16, and 10, respectively). Reseeding or <br />interseeding with the permanent seed mix took place during the autumn of 1998 within these <br />areas with the goal of increasing perennial graminoid representation. <br />The 1999 reclamation areas encompass a total of 17.36 acres of reclamation in two distinct <br />parcels within the Keenesburg Mine permit area. The areas are found on the south and east <br />sides of the mine; Reclamation Area 5, a 2.63 acre parcel south of the topsand piles, and <br />Reclamation Area 9, 14.73 acres of the former A Pit. Reclamation Area 5 is nearly flat with <br />Coors Energy Company Keenesburg Mine Page 4 <br />2011 Vegetation Sampling: Phase 111 Eligible Areas <br />