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• Vegetation Production - 1987. Quantitative measurements of vegetation production were made in the <br />sagebrush, irrigated pasture, graminoid component of the Swale/drainage, and irrigated hayland <br />vegetation types. <br />Prior to the spring growing season in 1987, grazing exclosures were installed in the sagebrush, irrigated <br />pasture, and graminoid component of the Swale/drainage types. Fifty randomly-located sample points, <br />protected by grazing exclosures were located in the irrigated pasture type. Thirty protected sample <br />points were randomly located in the sagebrush and Swale/drainage types (graminoid component). The <br />grazing exclosures were designed in the shape of a cone with a circular base that exceeded 1m in <br />diameter. The exclosures were constructed with four-inch mesh woven wire and were anchored in the <br />ground with rebar. The cages remained in place until the production samples were collected. <br />With the exception of the graminoid component of the Swale/drainage type, all production data was <br />collected concurrently with measurements of vegetation cover and frequency. The 30 original exclosed <br />plots in the Swale/drainage areas were sampled concurrently with the cover and frequency data as well. <br />However, ongoing negotiations with the OMLR regarding sampling intensity in the type, and the lack of <br />achieving sample adequacy with 30 observations necessitated further sampling. The additional samples <br />were obtained in mid-August from 21 randomly-located plots that had not been protected from grazing. <br />• This inconsistency was determined not to be a problem since little or no livestock utilization was <br />observed in the Swale/drainage type. In fact, the modified study design prescribed that randomly-located <br />plots in which any indication of utilization was detected would be discarded for sampling purposes. <br />However, no such plots were encountered. The range in sampling dates (approximately 30 days <br />between the dates of the two samples) did not introduce significant temporal variation in the overall <br />sample since most of the vegetation was in apost-reproductive (maintenance) growth phase during the <br />interval belween samples. No attempt was made to sample production in the willow component of the <br />Swale/drainage primarily because of immeasurability. <br />Measurements of above-ground plant biomass were made using a 0.25m' circular plot in both the <br />graminoid component of the Swale/drainage and irrigated pasture types. A 1.Om' plot was used In the <br />sagebrush type. Within each production plot, all green, living herbaceous plant material was clipped as <br />close to ground level as possible, separated by lifeform (annual forbs, annual graminoids, perennial <br />forbs, and perennial graminoids), immediately weighed using Pesola field scales, and bagged for <br />laboratory analysis. Herbaceous plant material was not sorted in the irrigated pasture samples. In the <br />laboratory, samples were oven-dried at 30°C in a forced draft oven for 72 hours, or until a constant <br />weight was obtained. Dry weights were obtained on an Ohaus top-loading electronic balance which is <br />accurate to the nearest 0.01 gm. <br />• (REVISED 8/15/00) 2.04.1 ~ - 16 <br />