2013-04-10_PERMIT FILE - C1981019A (4)

Home Browse Search

RULE 2 PERMITS diversity estimates. Second hits on litter, rock, or bare soil were ignored. Only first -hits were used for the determination of ground cover. Plant identification and nomenclature follows Weber and Wittman 1996, Winward 2004, and USDA Forest Service 1977. Current Annual Herbaceous Production - At each production sample site, current annual herbaceous production was collected from either 1 meter squared (m2) (Juniper Scrub type) or 1/2 m2 (all other types) quadrat frames placed one meter and 90 degrees (0) to the right (clockwise) of the ground cover transect. All above ground herbaceous vegetation of the current year growing within the vertical boundaries of the frame was clipped and bagged separately by the following life form categories: Perennial Grass, Perennial Forb, Noxious Weed, Annual Grass, Annual / Biennial Forb, and Sub - shrub. All production samples were returned to the lab for drying and weighing. Drying occurred at 1050 Celsius (C) until a stable weight was achieved (24 hours). Samples were weighed to the nearest 0.1 gram. Woody Plant Density - At each sample site in the baseline inventory area and at 30 of the 40 production sample points in the reference areas, a 2 -meter wide by 50 -meter long belt transect was established to determine woody plant density. All shrubs, sub -trees (e.g., Gambel's oak) and trees were enumerated by species. Determination of whether or not a plant could be counted was dependent upon the location of its main stem or root collar where it exited the ground surface with regard to belt limits. Sample adequacy was determined for informational purposes only. Aspen Density & Canopy Cover - At each ground cover sample site in the aspen reference and baseline areas, the point- center - quarter (PCQ) method was used to determine aspen density. At each sample point, the surrounding area was horizontally divided into four quarters (quadrants) using the cardinal compass directions (northeast, northwest, southeast, and southwest quadrants). Within each quadrant, the distance to the nearest aspen (at least 5 feet in height) from the sample point was measured to the nearest foot (Y,). Using the following equation, an aspen density was determined from these four measurements: Aspen Density ( /ft2) = 3 /[7c(Y12+ Y22+ Y32+ Y42) /4] At each sample point, canopy cover was visually estimated. Aspen canopy at over half the sample points was substantially reduced due to the recent die -off of mature trees (most likely due to the recent drought). Sample Adequacy Determination — A minimum of 20 samples were placed within each community type of both the baseline and the reference areas. Ground cover and production information was collected at each location. From these initial samples, a mean and standard deviation for each variable was calculated. Where statistical testing is required (for the establishment of qualified reference areas), collection of an adequate sample (nmin) is typically necessary to insure reliable estimates of the population (e.g., estimates to within 10 percent of the true mean (g) with 90 percent confidence). The Cochran formula below was utilized in accordance with directives in Colorado's guidelines (1988). When the inequality (nmin < n) is true, sampling can be considered to be adequate, and nmin is determined as follows: nmin = (t2S2) / (0.1.x )2 Where: n = the number of actual samples collected with a minimum of 20 in each unit; t = the value from the t distribution for 90 percent confidence with n -1 degrees of freedom; s 2 = the variance of the estimate as calculated from the initial samples; z = the mean of the estimate as calculated from the initial samples. Cullom — Rule 2, Page 59 Revision Date: 9/28/11 Revision No.: PR -03