Laserfiche WebLink
2.0 METHODOLOGY FOR VEGETATION SAMPLING/ COMPARISON METHODS <br />2.1 Sample Site Selection / Location <br />The sample layout protocol for revegetation evaluations in 2007 and 2008 largely followed CDRMS <br />approved procedures developed by Cedar Creek to provide unbiased, representative, and cost - effective <br />data for evaluation of revegetation. These procedures are designed to better account for the <br />heterogeneous expression of vegetation within the various reclaimed areas while precluding bias in the <br />sample site selection process. By design, the procedure is initiated randomly, and thereafter, samples <br />are located in a systematic manner, along grid coordinates spaced at fixed distances, e.g. 200 ft. (see <br />Figure 1 or Maps 1 - 3 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. <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. Second, a systematic grid of appropriate dimensions was selected to provide <br />a reasonable number of coordinate intersections (e.g., 20 or 30) that could then be used for the set of <br />sample sites. Third, a scaled representation of the grid was overlain on a computer- generated map of <br />the target unit extending along north /south and east /west lines. Fourth, the initial placement of this grid <br />was implemented by selection of two random numbers (an X and Y distance) to be used for locating the <br />first coordinate from the fixed point of reference, thereby making the effort unbiased. Fifth, where an <br />excess number of potential sample points (grid intersections) was indicated by overlain maps, the excess <br />were 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 GPS or handheld compass and pacing techniques (or a hip- chain), the <br />sample points were located in the field. <br />Once a selected grid point was located in the field, ground cover sampling transects 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 />Depending on logistics, timing, and access points to the target sampling area, the field crew would <br />occasionally layout a set of points along coordinates in one direction and then sample them in reverse <br />order. However, orientation protocol was always maintained (i.e. in the direction of the next point to be <br />physically sampled). If the boundary of an area was encountered before reaching the full length of a <br />transect, the orientation of the transect was turned 90 in the appropriate direction so the transect could <br />Cedar Creek Associates, Inc. Page 10 Colowyo Mine - Bond Release Evaluation <br />Phase III Year 2 <br />