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2.6 Summary by Area <br />2.6.1 East Pit <br />Tables 4 and 5 exhibit the average cover and composition of vegetation found on five of the East Pit <br />unitr evaluated in 2003. Units EP028 and EP029 (7 growing seasons) have progressed well toward <br />meeting bond release criteria with the exception of woody plant density. Perennial cover (43.0% and <br />45.4%) and production (725 and 950 pounds per acre) should readily pass comparisons with the <br />reference areas. Similarly, the present diversity of perennial g2sses and forts (6 and 5 perennial <br />grasses & 1 and 1 perennial forts), respectively, meets the standard of 3 perennial grasses and 1 <br />perennial fort with between 3% and 50°r6 relative cover. Woody plant density in both EP028 and EP029 <br />is low at 20 and 101 woody plants per acre, respectively, (in comparison to the present standard of 90% <br />of 1,000 woody stems per aae). See Appendix AA -Section 7.4 for a discussion on options and <br />recommendations with regard to woody plant density. Although annual bromes currently represent only <br />IO% cover in EP028, these patches should be monitored to gauge if they are expanding or shrinking. If <br />monitoring reveals that they are expanding, use of the herbicide Oust or Plateau is recommended. <br />• Units EP034 and EP035 are exhibiting mbced results after four growing seasons. Annual bromes <br />have completely invaded EP035 occupying nearly 75% of the vegetative composition, while they have <br />partially invaded EP034 exhibiting over 35% relative cover. Perennial vegetation is present throughout <br />most of these units, but may be losing the competition for resources by the annual bromes. It is <br />recommended that both these un""ns be sprayed with the herbicde Oust or Plateau m control the annual <br />bromes. Spot reseeding may be necessary in isolated patches without a remnant population of perennial <br />vegetation. Woody plant density is also low in both of these units. <br />Unit EP038 is exhibiting positive results after two growing seasons. Annual brome populations are <br />low, although monitoring needs to continue over the next couple of years to document any problematic <br />invasion. The non-invasive annuals, Russian thistle and field pennycress are currently the dominant <br />species and will quickly disappear in the next few years when elevated soil nutrient availability returns to <br />lower levels. A moderately high woody plant density of 264 plants per acre is encouraging considering <br />the young age of the revegetation. <br />Flrst year emergent sampling on Units EP037, EP042, and EP043 has revealed generally good <br />. revegetation with a couple exceptions. EP042 is showing very promising results after one growing <br />season with over 12,000 shrub seedlings emerging per acre and no annual bromes. EP043 is also <br />Kennecott Energy Co. / Colowyo Mare Page 67 Revegeta0on MonnOring -2003 <br />