PERMFILE128722 - Laserfiche WebLink

Home Browse Search

Methodologies ~• The following discussion of methodologies covers vegetation baseline studies conducted on the current permit area and tie-across haul road corridor through 1983. Although some reference is made to the 1985 tie-across haul road vegetation studies, the primary discussion for methodologies relevant to that study are contained in Appendix 10-8. Methodologies for the 1990 baseline studies may be found in the study report contained in Appendix 10-9. Sample Point Selection. During the 1979, 1980, and 1982 field seasons, sample point locations were randomly determined using a grid coordinate system and a random numbers table in the office prior to sampling. A gridwork was placed over the vegetation map, with grid lines parallel to section lines. The southwest corner of each section was chosen as the origin, and coordinates were generated using a random numbers table. Grid size was sufficiently small (100 feet x 100 feet) to ensure that any point would have an equal lik elihood of being sampled. A total of 60 points for each vegetation type were initially mapped. Each mapped point was then assigned a code number for identification purposes. In the field, when each mapped sampling point was located, a wooden stake was , • tossed in a random direction to mark an unbiased exclosure location or plot centerpoint. Exclosure locations and sampling points within the original reference areas were determine d by starting at the northeast corner of each reference area and obtaining a random or ientation and distance to the first sample point. The first sample point then served as the reference point for locating the next sample point and the process continued until all sampling points had been located. During the 1983 field work, all sample sites (for both the permit area and the original reference areas) were chosen by using random number pairs as Cartesian coordinates. Grid cell size was 200 feet x 200 feet in the permit area and 1 m x 1 min the reference areas. A similar method was employed during the 1985 tie across haul road verification studies. Exclosure Installation. During the 1980 and 1985 field studies, no exclosures rre re installed along the haul road corridor because there was no livestock grazing. Production data was collected from the aspen, sagebrush, and mixed brush vegetation types in the permit area during the 1983 field season. At each sample location, a cone slia prd rvire exclosure was erected to protect plants from grazing prior Lo clipping. these wire e