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• An uncertain determination to speces is denoted in the tables by the latin abbreviation, c.f. Identification <br />and nomenclature of plant species follows Weber and Wittman's Colorado Flora: Western Slone - <br />Revised Edition: 1996: University Press of Colorado. Niwot, Colorado. <br />2.3 Determination of Current Annual Herbaceous Production <br />At each sample site within the irrigated hayland, current annual herbaceous production was collected <br />from a'/2 rr~ rectangular quadrat frame placed one meter from the marked sample point (see Figure 1). <br />From within each quadrat, all above ground current annual vegetation, with the exception of woody <br />species, within the vertical boundaries of the frame was clipped and bagged separately by life form as <br />follows: <br />Perennial Grass and Fortis Annual Grasses and Fortis <br />Noxious Weeds <br />Alt production samples were returned to the lab for drying and weighing. Drying occurred at 105° C <br />until a stable weight was achieved (24 hours). Samples were then re-weighed to the nearest 0.1 gram. <br />Wet weights determined in the field were used to facilitate the collection of an adequate sample. <br />2.4 Sample Adequacy Determination acrd Testing for Success <br />Sampling within each revegetated community type for ground cover (sagebrush /grassland) and <br />production (irrigated hayfield) was conducted to a minimum of 15 transects. Reference area sampling for <br />the variable of ground cover was conducted to a minimum of 10 transeds. From These initial samples, a <br />mean and standard deviation for each variable was calculated. Collection of an adequate sample (nml,J <br />is typically necessary to insure reliable estimates of the population (e.g., estimates to within 10% of the <br />true mean (p) with 90% confidence). Although statistical testing is not a necessary requirement ~~, the <br />minimum number of samples necessary was determined to establish scientific defensibility and comply <br />wRh Colorado Guidelines. In this regard, the Cochran formula below was utilized in accordance with <br />As stated in Colorado's April 1B, 1995 guidelines, Part 4 (page 19), statistical testing for demonstrations of <br />. revegetation success is not necessary 'ii the parameter sample mean for the bond release block is equal to or <br />greater than 90 percent of the reference area ... or 90 percent of the approved technical standard'. 'Other than a <br />demonstration of adequate sample size, no statistical calculations [or hypothesis testing] are required in this case to <br />document success.' <br />~~ 67B®S AcoID¢.'nv~s. Ir+c. Page 8 NCIG -Coal Rldge I7 - Phasa II Bond Release Eraluatlon <br />