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Herbaceous ~oduction. Herbaceous production will be determined by harvesting <br />current growing season above ground herbaceous vegetative biomass from <br />randomly located quadrats. Quadrats will be located in conjunction with cover <br />transects. Quadrat size will be determined based on predominant vegetation <br />characteristics, and will be consistent with requirements of the Colorado Division <br />of Minerals and Geology. At this time, previous experience suggests that 0.25 m2 <br />quadrats will adequately represent the vegetation present in the reclaimed and <br />reference areas. Harvested material will be separated by life form (perennial <br />grasses, annual grasses, perennial forts, and annual forts) and oven dried to a <br />consistent weight in accordance with accepted scientific practice. Herbaceous <br />production data will be collected from both the reclaimed area and reference area. <br />For bond release, sufficient numbers of samples will be collected to reach sample <br />adequacy. <br />Woody plant densiri. Since there is no revegetation success standard for woody <br />plant density at the Keenesburg Mine, no woody plant density sampling is <br />proposed. <br />Species composition. Species composition data will be derived from the total and <br />relative vegetation cover data. All species sampled will have relative cover data <br />tabulated for comparison to the species composition standard. <br />Sample adeouacv. For bond release purposes, a minimum often cover transects <br />~' and ten production quadrats will be sampled in the Osgood reference area. A <br />minimum of fifteen cover transects and fifteen production quadrats will be sampled <br />in the reclaimed area. For vegetation monitoring purposes, the minimum number <br />of samples in the reference and reclaimed areas may be less, with the agreement of <br />the CDMG. <br />Sample adequacy calculations will be made for both vegetative cover and <br />herbaceous production sampling in the reclaimed and reference area. The <br />following formula will be used for these calculations: <br />(t)2 (s)2 <br />,_ <br />rmn - ---------------- <br />(d Xbar)2 <br />where: non =minimum sample size <br />n= number of samples <br />t =the Student's t distribution value at the 90% confidence level <br />for n-1 degrees of freedom <br />s =sample standard deviation {s)2= sample variance <br />d =percent acceptable deviation from the mean (10%) <br />Xbar =sample mean <br />116a <br />