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FIELD SAMPLING <br />• Vegetation Cover <br />Vegetation cover was estimated by the use of the point-intercept method. An ocular <br />point frame (ESCO Associates) was used to minimize instrument error and maximize <br />precision and observer accuracy. Cover transects were 25 meters in length, with two <br />sample data points collected at 1.0 meter intervals along the transect on opposite sides <br />of the transect centerline, 1.Sm apart. Transect direction was established randomly <br />through the use of a spinner. In no event were transects allowed to extend within ten <br />feet of reference or revegetated area boundaries to minimize impacts from "edge <br />effect." <br />For statistical purposes, each cover transect (comprising 50 data points) served as a <br />sample unit. Data points recorded the first vertical "hit" on vegetation (above or below <br />the instrument), soil (bare ground), rock, or fitter. Subsequent "hits" on vegetation <br />were also recorded. Cover data were recorded and reported by individual plant <br />species. The first interception was used to calculate total vegetation cover values. <br />Additional interceptions were used to calculate relative cover of individual plant species <br />and lifeforms. The quantitative cover data also provided the basis for calculation of <br />species composition and relative importance. <br />• Species Composition <br />Species composition information was computed from initial and subsequent hits from <br />vegetation cover data. Relative cover information provided a basis for evaluation of the <br />importance of each encountered plant species. <br />SAMPLE ADEQUACY <br />Sample adequacy calculations were undertaken for vegetative cover sampling in the <br />reference and reclaimed areas. The following formula was used for these calculations: <br />(t)2 (s)2 <br />nmin = -------------- <br />(d Xbar)2 <br />where: nmin =minimum sample size <br />t =the Student's t distribution value at the 90% two-tailed confidence <br />level and v (n-1) sample degrees of freedom <br />s =sample standard deviation (s)2= sample variance <br />d =percent acceptable deviation from the mean (10%) <br />Xbaz =sample mean <br />• <br />-3- <br />