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• Woody plant Density: For purposes of comparisons in this document, woody plant density at the Seneca II-W Mine is evaluated using a technical standard of 2000 shrubs per acre. Climatic Data Precipitation data were collected at the Seneca II-W Mine during 1998 and 1999. For all previous years, SCC provided precipitation data from the nearby Seneca II Mine for the period of January 1982 through December 1997. Since the data record for that mine exists for only 17 years, the long term average monthly precipitation data from the National Oceanic and Atmospheric Administration (NOAA) for the nearby town of Hayden was used as an appropriate base for comparison. Information on degree-days was based on temperature data derived from the NOAA records at Hayden. RESULTS Data from the 1999 revegetation monitoring studies at the Seneca II-W Mine are presented in Tables 1 through 16 contained in Appendix 1. The list of plant species observed during these studies (reclaimed and reference areas) are included in Table 10 in Appendix 2. Seed mixes used in the reclamation areas are included for reference in Appendix 3. Photographs of representative locations within the reclaimed areas sampled in 1999, as well as photographs of the Mountain Brush and Sagebrush reference areas are included in Appendix 4. Graphic depiction of summaries of vegetation and climate data are presented in Figures 1 through 10 of this report. ~_ In the cover descriptions below, species listed as "also present" were not "hit° during point- intercept sampling but were present within one meter on either side of the 50 m sample transect • line. Cover percentages referred to in the following results as "percerit of total vegetation cover" are relative vegetation values. 1995 Reclaimed Area (Photographs 1 through 4) Cover (Table 1) Native perennial cool season grasses comprised the dominant lifeform in this area and provided 66.5 percent of total vegetation cover. Mountain brome (Ceratachloa carinata) provided more than two-fifths of this total. Agassiz bluegrass (Poo agassizensis) and western wheatgrass (Pascopyrum smithi~) were also major contributors. Eleven other species made measurable contributions to total vegetation cover. Introduced annual and biennial (orbs contributed an average 10.7 percent of total vegetation cover. Twolobe speedwell (Pocilla biloba) was the dominant species in this lifeform and contributed one-half of total cover. Pennycress (Thlaspi arvense) and salsify (Tragopogon dubius ssp. major) combined to contribute more than one-third of this total. Prickly lettuce (Lactuca sernola) and Jim Hill Mustard (Sisymbrium altissimum) were relatively minor contributors. Introduced perennial forbs averaged 6.7 percent of total vegetation cover. Canada thistle (Breea arvensis) averaged nearly nine-tenths of this total and was the dominant species in this lifeform. Cicer milkvetch (Astragalus titer) and alfalfa comprised the balance. Introduced perennial grass contributed 6.3 percent of total vegetation cover. Orchard grass (Dactylis glomerafa) contributed more than one-half of this total. The balance was comprised of smooth brome (Bromopsis inermis) and intermediate wheatgrass (Thinopyrum intermedium). Introduced annual grass contributed 4.9 percent of total vegetation cover. More than nine-tenths of this total was contributed by Japanese brome (Bromus japonicus). The balance was comprised of cheatgrass (Anisantha tectorum). Native annual and biennial forbs accounted for 2.2 percent of total vegetation cover. Bigfruit willowherb (Epilobium brachycarpum), gumweed (Grindelia squarrosa) and microsteris (Microsteris gracilis ssp. humilis) • each contributed to this total. Native perennial forbs contributed 1.3 percent of total vegetation cover. Blue flax (Adenolinum lewisii) and two-groove milkvetch (Astragalus bisulcatus) made measurable contributions. Twenty-three other species were present but not encountered