Laserfiche WebLink
Some areas mapped as such may occasionaly receive supplemental moisture during the <br />growing season from adjacent agricultural activities, however, a sagebrush overstory with an <br />associated understory of introduced and native species are present along with the irrigated <br />pasture invader species Kentucky bluegrass. Attachment 2.04.10 -8, Figure 4 -6 (formerly <br />Peabody Appendix 10 -4) shows one of the larger blocks of this type in the study area. A <br />grazing exclosure is also shown in the photograph. <br />Total vegetation cover (first hit) for the type averaged 37 percent, with bare ground at 29 <br />percent, litter at 30.2 percent, and rock at 3.7 percent (Table 2.04.10 -11). Lichen and moss <br />accounted for only 0.1 percent of the mean cover. The shrub component dominated with 13.5 <br />percent cover followed closely by the annual grass component at 12.7 percent cover. <br />Perennial grasses and forbs at 7.3 and 2.6 percent cover, respectively, followed in importance. <br />Consistent with the type designation, Basin big sagebrush (Artemisia tridentata ssp. tridentata <br />had the highest perennial species cover at 11.5 percent (97 percent frequency), while the <br />ubiquitous invader of sagebrush rangelands, cheatgrass ( Bromus tectorum had the highest <br />cover for any species at 12.7 percent (90 percent frequency). Kentucky bluegrass had the <br />third highest cover at 2.7 percent (43 percent frequency) and blue grama ( Bouteloua oracilis <br />crested wheatgrass ( Aoropvron desertorum hairy goldenaster ( Heterotheca villosa broom <br />snakeweed ( Gutierrezia sarothrae all had approximately 1 percent cover. The remaining <br />species generally contributed less than one half percent cover to the mean total vegetative <br />cover. <br />Herbaceous production totaled 20.0 g /m2 or 178.4 pounds /acre (Table 2.04.10 -12). The <br />perennial grass component contributed the highest value at 13.6 g/m (242.4 pounds /acre) <br />followed by perennial forbs at 5.4 g /m (96.2 pounds /acre). While the contribution of annual <br />grasses 2 and forbs was low (0.2 and 0.8 g /m , respectively), their actual contribution to <br />annual production is most likely higher. In order to sample the perennial species at the peak of <br />their production, many of the earlier maturing annual species were senescent or were already <br />gone from the stand. <br />Revised September 2010 (PR 06) 2.04.1045 <br />