Laserfiche WebLink
• vegetation cover. Timothy, an introduced perennial cool season grass, and pricklypear cactus <br />(Opunfia polyacanfha), a succulent, each contributed an average of 0.5 percent of total <br />vegetation cover. <br />Total vegetation cover was 42.6 percent. Standing dead, litter, and bare soil averaged 2.4, 41.8, <br />and 13.2 percent, respectively. Species density averaged 27.3 species per 100 sq. m. <br />Production (Table 5) <br />Total herbaceous production for all species other than alfalfa was 1074 Ib/ac. Nc alfalfa was <br />observed in this reference area. <br />Discussion <br />Climatic Conditions <br />Late 1998/ early1999 precipitation was up and down, with August, November, December, <br />February and March all below average, and the other months above average (Figures Sa and <br />5b). The total for the year ending in July 1999 (Figure 6) was comparable to the drought years of <br />the period from 1988 to 1990 as well as the individual dry year of 1994. When viewed over <br />shorter terms (Figures 7 and 8), 1999 is in the middle of the range of variation but in the upper <br />echelon of individual years since the distribution of values far four and six month cumulative totals <br />is distinctly skewed to the dry side (at least in July). With respect to warmth of the growing <br />season, as reflected in the cumulative degree-days shown in Figure 9, 1999 was very near the <br />long-term average. This contrasts with the last tour years that had been below average in <br />warmth. Of particular interest in the pattern of vegetational growth shown in 1999 was the very <br />dry August in 1998 and the very wet April, May, and July of 1999. <br />• Cover <br />Total herbaceous all-hit cover in the Sagebrush Extended Reference Area was 30.8 percent. <br />This value was adjusted for stratification differences between the reference and reclaimed areas <br />by the first hit to all hit ratio of 0.9957 to give a performance standard for all hit herbaceous cover <br />of 30.7. 90 percent of this value is 27.6 percent, which is shown on Figure 1. As can be seen <br />there, the average herbaceous all-hit cover of the five diverse reclaimed area samples was 39.2 <br />percent, well above the standard. <br />Samples 1 and 3 had overtwo-thirds of vegetation cover comprised by annual/biennial species. <br />Sample 2 had no part of measurable cover attributable to annual or biennial species. Sample 4 <br />had only 7 percent of total vegetation cover in annuals or biennials, while for Sample 5, that figure <br />was 20 percent. Thus, the threshold of 10 percent applicable to Phase 2 bond release <br />considerations was grossly exceeded by Samples 1 and 3 where no seeding may have taken <br />place. Samples 2 and 4 would have satisfied the annual composition criterion, but Sample 5 has <br />more annual/biennial cover than would be permitted, were a Phase 2 bond release to be sought <br />there. <br />Herbaceous Production <br />Herbaceous production averaged over the five diverse samples of reclaimed area conditions <br />substantially exceeded the performance standard set by the samples of the sagebrush reference <br />area along the mine access road. Because of the youth of these stands, most have a substantial <br />proportion of the herbaceous production comprised of annual/biennial species, especially <br />Samples 1 and 3. <br />Woody Plant Density <br />At this point, the sampled reclaimed areas have a relatively low density of woody plants. <br />• <br />