Laserfiche WebLink
1 <br /> <br /> <br /> <br />Vegetation Sampling For 1992 <br />.s~~xb~ <br />Two reference plots were established by WF[I during the summer of 1990. One plot has <br />a northern exposure and one has a southern exposure. Within each exposure, four 100 by <br />100 foot plots were constructed and seeded as descn'bed in the Study Plan Design section <br />above. Vegetative sampling was conducted on 3 and 4 August 1992. <br />Methods <br />1 <br /> <br /> <br /> <br /> <br />1 <br /> <br /> <br />1 <br />1 <br /> <br /> <br />1 <br />Vegetative sampling was conducted using 30-meter (100 ft) long point-intercept transects. <br />The actual number of transects conducted in each of the areas was determined by a <br />systematic design which was agreed upon by DMG prior to going to the 5eld. Ten transects <br />were randomly located on a line extending along the uphill axis of each reference plot. <br />Transects were ]aid across the plots perpendicular to the base axis. Sample adequary was <br />calculated using the Snedecor-Cochran sample adequary formula (Equation 1). <br />t~ s= <br />Nom, _ (fi)r <br />(1) <br />Where: <br />n = required number of transects or quadrats, <br />r = 1.64 (the tti,b~ value for adouble-tailed t-test with infinite degrees of freedom <br />at the 90% confidence level), <br />s' = sample variance, <br />d = 0.1 (the level of precision for estimate of the mean to be within 10% of the <br />actual mean), and <br />s = sample mean. <br />Sample adequacy was reached on each plot in ten transects. <br />Ground cover was evaluated along each transect at 0.3-m (1 ft) intervals. This method was <br />used instead of the 10 point frame due to the close proximity of transects, variability of cover <br />in some plots, and the utilization of these same transects for the woody plant density <br />analysis. Cover was classified as vegetation, litter, or rock. Lack of cover was classified as <br />bare soil. Vegetation was further classified by species. Each transect consisted of 100 <br />sample points. Each point was determined by projecting an ocular sighting device vertically <br />downward to the sample location on the transect and recording all "hits" on vegetation. The <br />8 <br /> <br />