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• success standard orapproved technical standard, then revegetation will be considered <br />successful for that parameter. <br />WOODY PLANT DENSITY: For purposes of illustration, woody plant density at the Yoast Mine is <br />evaluated in this document using a technical standard of 2000 shrubs per acre. <br />Climatic Data <br />No precipitation data are collected at the Yoast Mine. In its place, SCC provided precipitation <br />data from the nearby Seneca II Mine fpr the period of January 1982 through December 1997, <br />supplemented with data from the Seneca II-W Mine for January 1998 through September 1999. <br />Since the long-term average for that mine exists for only 17 years, the long term average monthly <br />precipitation data from the National Oceanic and Atmospheric Administration (NOAA) for the <br />nearby town of Hayden was used as an appropriate base for comparison. Information of degree- <br />days was also derived from the NOAA records at Hayden. <br />RESULTS <br />Data from the 1999 revegetation monitoring studies at the Yoast Mine are presented in Tables 1 <br />through 9 contained in Appendix 1. The list of plant species observed during these studies <br />(reclaimed and reference areas) are included in Table 10 in Appendix 2. Seed mixes are <br />included for reference in Appendix 3. Photographs of representative locations within the <br />reclaimed areas sampled in 1999, as well as photographs of the sampled portions of the <br />Sagebrush extended reference area are included in Appendix 4. Graphic depiction of summaries <br />of vegetation data, precipitation, and total degree days are presented in Figures 1 through 9 of <br />this report. <br />In the cover descriptions below, species listed as "also present" were not "hit" during point- <br />. intercept sampling but were present within one meter on either side of the 50 m sample transect <br />line. Cover percentages referred to' in the following results as "percent of total vegetation cover" <br />are relative vegetation values. <br />Reclaimed Areas <br />(Photographs 1 through 4) <br />Reclamation at the Yoast Mine available for sampling in 1999 included heterogeneous areas <br />along and near the mine access road. Some of these areas very likely have not been seeded, <br />and are likely to be reworked prior to final reclamation. The limited sampling done here in 1999 <br />serves as a snapshot of interim conditions; as more area is reclaimed at this mine, monitoring will <br />address larger more homogeneous tracts as has been done at the Seneca II and II-W Mines <br />nearby. <br />Cover (Table s ) <br />Samples 1 and 3 exemplified areas that may not yet have been seeded with the perennial seed <br />mix and, consequently, were dominated by annual and biennial (orbs, both native and introduced. <br />Species of annual and biennial forbs present are typical of early successional stages of <br />development and do not represent serious threats to permanently occupy these sites. Species <br />present include prickly lettuce (Lactuca serriola), red-root pigweed (Amaranfhus retroflexus), <br />tarweed (Madia glomerata), pennycress (Thlaspi arvense), common sunFlower (Helianthus <br />annuus), and salsify (Tragopogon dubius ssp. major). In these samples(1 and 3), the <br />development of perennial plants has been very limited. In addition, total vegetation cover on <br />these sites was relatively low, ranging from 18 to 28 percent in the two samples (1 and 3). <br />Sample 2 exemplified an area where seeded perennials were dominant and in which alfalfa <br />(Medicago saliva) was especially abundant (44 percent ground cover). Perennial grasses, both <br />• native (6 percent cover) and introduced (8 percent cover) were moderately abundant. The high <br />abundance of alfalfa contributed to a relatively high total vegetation cover (60 percent). <br />