Laserfiche WebLink
RULE 4 PERFORMANCE STANDARDS <br /> sample can be obtained from the reference area, then a less complex one-sample t-test may be <br /> utilized. With the reverse null test, the smaller the variance (given by extra sampling) the better <br /> the chances of passing closely matched parameters. <br /> For certain statistical demonstrations of woody plant density,documentation of sampling adequacy <br /> is often problematic,hence Rule 4.15.11 (3)may be used in lieu of Rule 4.15.11 (2). Rule 4.15.11 <br /> (3) (a) is a reverse-null approach based on the median and requires a minimum of 30 samples. <br /> Rule 4.15.11 (3) (b) allows direct comparison with standards if a statistically adequate sample <br /> cannot be demonstrated in accordance with Rule 4.15.11 (2) (a), however, a minimum of 75 <br /> samples with a minimum quadrat size of 100 m2 is required (equivalent to total enumeration of <br /> 1.85 acres). Rule 4.15.11 (3) (c) is a standard-null approach based on determination of a"running <br /> mean" and a minimum of 40 samples is required. <br /> Success Evaluation <br /> To summarize, success evaluations involve either a direct or a statistical t-test comparison of <br /> appropriate parameters for each variable of interest (cover, production, diversity, or woody plant <br /> density). For monitoring efforts,comparisons shall be made directly with either the reference area <br /> parameters or the permitted standards to facilitate a determination of the progress of revegetation. <br /> In the case of ground cover and production,comparisons shall be made against reference area data <br /> of the same year. Diversity and woody plant density variables shall be compared against the <br /> standards defined above. <br /> For bond release efforts, direct comparisons are made when the revegetated area mean value for a <br /> given variable is greater than either 90% of the standard or the reference area mean assuming that <br /> a statistically adequate sample has been collected. If a statistically adequate sample cannot be <br /> obtained, a"reverse-null"hypothesis test may be employed as detailed in C.R.S. Rule 4.15.11 (2) <br /> (c). If an adequate sample is obtained for a particular variable, but the mean is less than 90% of <br /> the reference area mean or standard, a "standard-null" hypothesis t-test may be employed as <br /> detailed in C.R.S. Rule 4.15.11 (2) (b). <br /> For the typically problematic variable of woody plant density, Colorado has implemented three <br /> alternate adequacy/success evaluation methods under C.R.S.Rule 4.15.11 (3)that may be utilized <br /> in lieu of those detailed under 4.15.11 (2). Until experience dictates which procedure is best <br /> (because these are relatively new metrics to the science),it would be prudent to collect a minimum <br /> of 75 belt transects (at least 100 m2 in size) as indicated in 4.15.11 (3)(b)(i). These data can then <br /> be used for the various analyses/ comparisons. <br /> Rule 4 Performance Standards 4-68 Revision Date: 12/20/19 <br /> Revision No.: TR-135 <br />