Laserfiche WebLink
<br />Mr. Gregg Squire <br />-4- <br />January 7, 1985 <br />Where '=wt = Weighted value <br />xh = Value in type h <br />ah = Acreage in type h <br />A = Acreage in entire combined area (= s ah) <br />S = Standard deviation for entire combined area <br />Sh2 = Variance of type h <br />nh = Number of samples taken in type h <br />• <br />Cover and productivity on the reclaimed sites will be considered to be <br />successful if they are at least 90 percent of the values of the reference area <br />with 80 percent statistical confidence for previous pinyon-juniper areas, and <br />90 percent statistical confidence for areas that were grasslands prior to <br />mining. If cover and productivity values on the reclaimed area exceed 90 <br />percent of the values of the reference area, no additional calculations are <br />necessary to document revegetation success for cover and productivity. If the <br />values for the reclaimed area are less than the standards from the reference <br />area, hypothesis must be developed and statistical tests must be run to <br />determine the success or failure of revegetation efforts. Hypothesis to be <br />tested and procedures are as follows from Larson (1980): <br />Ho: Revegetated area > reference area standard <br />Ha: Revegetated area < reference area standard <br />t - test comparison: <br />to = kl - k2 <br />~- + _S? <br />nl n2 <br />Where to = Calculated estimate of t <br />x = Weighted mean for the revegetated area and <br />reference area standards <br />• <br />