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4 <br /> <br />'New ffnrimn-Mine: 1007 Vegefatiart Sampling for Phase 3 Bond Release <br />Cover was measured by a point intercept method. From random sample paints, a 100 ft tape <br />was stretched at a bearing of magnetic north { if a bearing caused the tape to cross the study <br />area boundary, then bearings of east, south, or west were substituted, in that order}. At 10 toot <br />intervals along the tape beginning at 10 feet, a point frame was positioned perpendicular to the <br />tape and extending to the left. The point frame consists of a meta( bar with tripod legs, <br />positioned parallel to the ground about 1 meter high. A sliding laser light pointer is positioned at <br />each of 10 marked points along the bar spaced 10 cm apart At each point the observers record <br />the object that first intersects the downward-pointed laser light (giant species, litter, rock, or bare <br />ground}. ten cover readings at each of 10 intervals along the transact yield 100 cover readings <br />per fransect, which are tallied and the total number of hits per species or object is equal to the <br />percent cover estimate for that transact <br />Production was measured by dipping and weighing current year aboveground herbaceous <br />growth within a square 0.25 m2 frame (irrigated pasture) or a rectangular 2 m2 frame {dryiand <br />pasture). Clippings ware segregated into paper bags by perennial grass, annual grass, <br />perennial loch, annual fort, noxious weed, and a few individual spe(ties {such as broom <br />snakeweed on the dryiand pasture reference area, pending decisions on how to group giant <br />... species for analysis). Bags were oven-dried at 90 degrees C to a constant weight, then the <br />contents weighed on a calibrated elet~ranic balance to the nearest 0.1 g. <br />For both cover and production, samples were taken in each study area until either sample <br />adequacy was reached {sea statistical procedures, below) or a mintmum of 15 to 30 samples <br />was reached, depending on the statistical methods. Sample adequacy voas calculated <br />periodica0y in the field during sampling by entering cover data and fresh weight production data <br />into a field laptop computer. After production samples were dried, and sample adequacy was <br />recalculated based an dry weights, A simple random sampling design was employed, and <br />samples were taken in the order ofthe arbitrary numbers assigned to random points. <br />2.3 Statistical Procedures <br />Sample adequacy was calculated using equation 1. <br />:: <br />Equation 1 9_ d ~ ~, <br />whtse: <br />n„ =minimum aan~plc xize <br />. . ,e' ,= Sang1le varixnco.(~I d:grecs ar frecdocu} <br />d ~ Prccisian (9.1Q far cover tmd pro4ucuaa; R.IS fnr wupdy <br />gtanL denairy) <br />x ~ Sarnplc aridvnetic mcen <br />t = Tl,c (ate. tiyj t•eabk vabue for o I p;t t-~at, n-S degnxc of <br />freedom (inrmitc dcgcces of Geaidocn maY tx oxd if n>10) <br />n - Samplc stu <br />Mean values far cover and production were calculated for each study area. Mean values far <br />each post mine land use type were compared to the standard {respective reference area <br />means) accordngto the generat procedures described above in section 1. Because different <br />statistical tests were used for different comparisons, statistical tests are described below In <br />section 3, Results. <br />810-Lagfc 1»vfrp»me»tal <br />November tZ 1007 <br />Attachment 1-6 <br />