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Methodology for Vegetation Sampling /Comparison Methods - Colowyo Mine <br />1.0 Sample Site Selection /Location <br />The sample layout protocol for revegetation evaluations in 2006 largely followed CDRMS approved <br />procedures developed by Cedar Creek to provide unbiased, representative, and cost-effectrve data for <br />evaluation of revegetation. These procedures are designed to better account for the heterogeneous <br />expression of vegetation within the various reclaimed areas while precluding bias in the sample site <br />selection process. By design, the procedure is initiated randomly, and thereafter, samples are located in <br />a systematic manner, along grid coordinates spaced at fixed distances, e.g. 200 ft. (see Figure 1 below <br />and Maps 2 - 14 in the main document). In this manner, "representation" from across the entire <br />reclaimed area is "forced" rather than risking the chance that significant pockets (or seedings) are <br />entirely missed, or overemphasized as often happens with simple random sampling. Older reclaimed <br />units (e.g., 7+ years) received 20 ground cover transacts and shrub density belts. Production was <br />collected from five of these 20 sample points from older reclaimed units. Younger reclaimed units (e.g., <br />2 to 4 years) received 15 transacts and belts (and no production sampling). First year units received one <br />cluster of five emergent density quadrats for approximately every two acres of reclamation. With regard <br />to any two-year old or older reclamation unit and smaller than approximately 2 or 3 acres, the number of <br />samples for monitoring is limited to 5. <br />The systematic procedure for sample location in the revegetated units occurred in the following <br />stepwise manner. First, a fixed point of reference was selected for the unit to facilitate location of the <br />systematic grid in the field. Sewnd, a systematic grid of appropriate dimensions was selected to provide <br />a reasonable number of coordinate intersections (e.g., 5, 15 or 20) that could then be used for the set of <br />sample sites. Third, a scaled representation of the grid was overlain on a computer map of the target <br />unit extending along north/south and east/west lines. Fourth, the initial placement of this grid was <br />implemented by selection of two random numbers (an X and Y distance) to be used for locating the first <br />coordinate from the fixed point of reference, thereby making the effort unbiased. Fifth, where an excess <br />number of potential sample points (grid intersections) was indicated by overlain maps, the excess were <br />randomly chosen for elimination. (If later determined that additional samples would be needed, the <br />eliminated potential sample sites would be added back in reverse order until enough samples could be <br />collected.) Sixth, utilizing a handheld compass and pacing techniques (or ahip-chain), the sample points <br />were located in the field. <br />Once a selected grid point was located in the field, ground cover sampling transacts were always <br />oriented in the direction of the next site to be physically sampled to further limit any potential bias while <br />facilitating sampling efficiency. This orientation protocol follows that which is indicated on Figure 1 <br />AA-2 <br />