2010-12-17_REVISION - C1981019 (160)

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acreage may have used a grid dimension of 200 x 200 to achieve sufficient intersections to provide approximately 50 sample points, whereas a community that occupied larger acreage may have needed grid dimensions of 500 x 500 to provide the target 50 points. Second, a scaled, computer generated representation of the nested 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 (see Map V1). Third, utilizing a hand held surveying compass, pacing techniques, or a GPS, all sample points were located in the field. All sample sites used for the 2005 sampling effort are indicated on Map V1. Because of the preliminary nature of the vegetation mapping at the time of field sampling, certain field modifications to the aforementioned procedure were necessary. Because preliminary mapping occurred without benefit of ground verification, a few polygons were misidentified and required correction. For example, significantly more Juniper Scrub had been mapped, than actually was observed following ground verification activities. The errant areas were later determined to be Sagebrush (Xeric subtype) or Mountain Shrub (Xeric subtype). In addition, certain other original delineations were combined based upon observed field characteristics. These included grassland and sage reduction areas under the grassland category and riparian, wetland, and other bottomland types under the bottomland category. To address these circumstances, the sampling distribution protocol was maintained, but the original nested grid dimension was often changed to provide additional or fewer samples as necessary. Occasionally, combined types ended up with significantly more than the 50 target samples. In other circumstances, where adequacy was an issue, nested grid dimensions were reduced purposefully to provide additional samples. In still other instances where additional acreage was added to a type, nested grid dimensions were increased to provide fewer samples than would otherwise have resulted, especially where variability was not problematic for collection of a statistically adequate sample. Finally, sample points occasionally landed within small, unmapped inclusions of another type (e.g. a patch of Sagebrush within a Mountain Shrub designation). Such samples were collected, but then labeled according to the actual community for which they belonged. Once a selected grid point was located in the field, sampling metrics were utilized in a consistent and uniform manner. In this regard, ground cover sampling transects were always oriented in the direction of the next site to be physically sampled to further limit any potential bias while facilitating sampling efficiency. This orientation protocol follows that which is indicated on Figure V-1. Depending on logistics, timing, and access points to the target sampling area, the field crew would occasionally layout a set of points along coordinates in one direction and then sample them in reverse order. However, orientation 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 • CEDAR CREEK MOC?AUSS, INC. Page 7 2005 Collom Vegetation Survey