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• Each group of ten points, with a 10cm interval between each point, was oriented perpendicular to the <br />transect such that five points were projected vertically downward (or upward for overhanging canopy) on <br />each opposing side of the transect. At each point, the first contact of a plant species was recorded as a <br />"hit". In cases where vegetation was not contacted, either bare ground (soil), litter, or rock hits were <br />recorded. Each hit represented one percent cover for a transect. For example, a plant species that was <br />contacted 15 times on a transect had an estimated cover of 15 percent for that particular transect <br />((15/100) x 100). Since the points were situated systematically along the randomly-located transects, <br />each transect (i.e., 100 data points) represented an observation in the sample. Therefore, the estimated <br />mean cover for a particular species in the vegetation type as a whole was derived by summing the <br />percent cover measured on each transect and dividing by the total number of transects sampled. <br />The point-intercept technique was also used to collect vegetation cover data in the irrigated pasture type, <br />although the sampling design was modified to accommodate the inherently greater cover found in the <br />type as compared to that encountered In the sagebrush. The samples were collected on September 15 <br />and 16, 1987. The sampling design consisted of 25 pairs of points, sampled at 1 m intervals along a 25m <br />transect to achieve 50 points per transect. A minimum of 15 transects, distributed throughout the type, <br />were sampled. The two points constituting a pair were spaced 1m apart on opposite sides and <br />perpendicular to the transect. The points were projected vertically downward (or upward if overstory <br />. canopy occurred) to record first hit cover of vegetation, rock, litter, or bare ground (soil). Percent cover <br />by plant species, or soil, litter, or rock was calculated by dividing the number of hits on each by the total <br />number of points sampled per transect and expressing the result as a percentage. For example, a <br />species with 2 hits on a transect had a cover of 4 percent ((2/50) x 100). The estimated mean cover for a <br />particular constituent in the vegetation type as a whole was derived by summing the percent cover <br />measured on each transect and dividing by the total number of transects sampled. <br />Vegetation cover data was collected in the graminoid component of the Swale/drainage type using plots <br />and ocular estimates (Cox 1976). The graminoid component comprises approximately 80 percent of the <br />Swale/drainage type in the study area and consists of extensive tracts of hydrophytic gramincids <br />surrounding isolated monotypic islands or stringers of cattail. The cattail islands and stringers range from <br />less than 0.1 acres to approximately 2.0 acres in size. The data was collected on July 21 and 22, 1987. <br />At each randomly-located sample point, a single 50 x 50cm plot (0.25m') was used. A total of 30 plots <br />were sampled. Ocular estimation involved observation of the vegetation, litter, rock, and bare ground <br />from a vertical perspective within the plot boundaries. The plots were marked with 10cm, 5cm, and <br />2.5cm divisions to facilitate estimates of percent coverage. The cover estimates considered the actual <br />• (REVISED 8/15/00) 2.04.10 - 14 <br />