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• 1 1• 1 2.0 SAMPLING METHODS 21 Sample Layout The sample layout protocol for the revegeffition evaluation is a procedure designed to better account for the heterogeneous expression of the multiple seedings within the various recaimed areas while precluding bias in the sample site selection process. By design, the procedure is initiated randomly, and thereafter, samples are identified in a systematic manner, along grid coordinates spaced at fixed intervals, e.g. 100 ft. (see Figure 1, lower left comer and Map 1). In this manner, "representation" hom across the entire reclaimed area is 'forced" rather than risking the chance that significant pockets (or seedings) are entirely missed, or overemphasized as often occurs with simple random sampling. Sample site selection within the reference areas occurred in a similar manner, although the grid dimensions were altered accordingly to accommodate the larger and smaller areas. The actual procedure for sample site location occurred as follows. First, a fixed point of reference locatable from year to year was selected. Second, a systematic grid of appropriate dimensions (e.g., 100 ft. X 100 ft.) was selected to provide approximately 15 coordinate intersections within each sampling unit, which could then be used for sample sites. Third, a scaled, computer generated representation of the selected grid was overlain on a computer generated map of the area utilizing north-south and east-west compass points which could be easily established in the field. Initial placement of the grid was controlled by the fourth step, selection of a pair of random numbers (between 0 and 100) used to facilitate location of the initial coordinate point from the fixed reference location. Fifth, using a hand held surveying compass and hip-chain (or pacing techniques) all sample points were located in the field and flagged. The locations of all 2001 sampling sites are indicated on Map 1. Once a selected grid point was boated in the field, ground cover sampling transacts were always oriented in the direction of the next site to be physically sampled to further limit any potential bias while faciliffiting sampling efficiency. This orientation protocol follows that which is indicated on Figure 1. Depending on logistics, timing, and access points to the target sampling area, the field crew would oxasionally layout a set of points along coordinates in one direction and then sample them in reverse order. However, orienffition protocol was always maintained (i.e. in the direction of the next point to be physically sampled). If the boundary of an area was encountered before reaching the full length of a transact, the orlentation of the transact was turned 90° in the appropriate direction so the transed could be completed. !n this manner, boundary transacts were retained entirely within the target unit by "bouncing" off the boundaries Page 5