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RULE 4 PERFORMANCE STANDARDS <br /> <br />Rule 4 Performance Standards 4-48 Revision Date: 4/9/25 <br /> Revision No.: MR-261 <br />utilized for bond release purposes unless shrub patches are too large (e.g., greater than 10 to 15 <br />acres) to practically utilize this technique (in which case belts will be utilized). This method <br />involves total counts of woody plant populations as opposed to estimates of mean densities through <br />statistical sampling. Implementation of the total count technique would involve circumscribing <br />the boundaries of a target polygon with hip chain thread or similar visible designation. Once a <br />unit is circumscribed in this manner, a team of two or more biologists walking shoulder-to- <br />shoulder traverse the plot enumerating each plant by species. The person farthest inside the line <br />of observers trails hip chain thread, or other means, to mark their path to prevent missing or double <br />counting specimens on subsequent passes. The distance between observers should be 15 to 20 feet <br />or less depending on the height of grasses and the presence of low growing taxa such as rose or <br />snowberry. Each internal observer should also “zigzag” as the team progresses, occasionally <br />turning to view the area just passed to ensure visual coverage of the entire survey path. Constant <br />communication among crew members precludes double counting or missing of plants located <br />along the margins of observed paths. Results from total enumeration efforts can be compared <br />directly with success criteria without statistical testing. <br /> <br />Sample Adequacy Determination <br />Sampling within each unit under consideration for bond release shall start with a minimum of 15 <br />(reference area) or 20 samples (revegetated area) and continue until a statistically adequate sample <br />has been obtained in accordance with Rule 4.15.11 (2). Woody plant density success comparisons <br />can be obtained utilizing Rule 4.15.11(2) or Rule 4.15.11 (3). For woody plant density adequacy <br />determinations utilizing Rule 4.15.11 (2)(a), the estimate is to within 15% of the true mean. Where <br />sampling is for managerial (monitoring) information, adequacy is not necessary and is calculated <br />for informational purposes only. <br /> <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). Ground cover and production comparisons shall be made against reference area data of <br />the same year. Diversity and woody plant density variables shall be compared against the <br />standards defined above. <br /> <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 in accordance with Rule 4.15.11(2)(a). If a <br />statistically adequate sample cannot be obtained, a “reverse-null” hypothesis test may be employed <br />as detailed in Rule 4.15.11(2)(c). If an adequate sample is obtained for a particular variable, but <br />the mean is less than 90% of the reference area mean or success criteria outline in Section 4.15.8, <br />a standard-null hypothesis t-test may be used in accordance with Rule 4.15.11(2)(b). <br /> <br />If adequacy for woody plant density cannot be achieved utilizing the formulation in Rule 4.15.11 <br />(2)(a), additional sample adequacy and success evaluation options are described under Rule <br />4.15.11(3). <br /> <br />