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• 1993 was the moistest period that has occurred during the years 1987 to 1993, in terms of <br />total precipitation for the previous 12 months (see Figure 7); it exceeded 1987 and 1992, the <br />previous wettest years in this measure. When ashorter-term cumulative measure of <br />precipitation is considered, such as 6 months (Figure 8) or 4 months (Figure 9), it can be seen <br />that 1993 was very moist, though less distinctly as cumulative period shortens. However, <br />1993 was a moderately warm year; total degree days at Hayden during the period of January <br />through June (Figure 10) was intermediate between the high extremes of 1987 and 1992 and <br />the low extremes of 1988, 1989, and 1991. This may have allowed photosynthesis to proceed <br />at a rapid rate without accompanying heavy evapotranspiration losses, explaining the <br />apparently very favorable growing conditions during 1993. <br />A summary of sample adequacy calculations for the parameters of cover, production and woody <br />plant stem density is presented in Table 26 (Appendix 1). As can be seen in Table 26, sample <br />adequacy was achieved or nearly achieved for all cover sampling (except for PECOCO Pasture, <br />which consisted of a mix of reclaimed and native vegetation), was sometimes close for <br />• production sampling, and was achieved for woody plant stem density in the reference areas only; <br />high variability in shrub presence in the reclaimed areas left calculated sample adequacy levels <br />mostly astronomical. <br />Of plant species observed during 1993 sampling, only Canada thistle (Cirsium arvensel, blue <br />lettuce (Lactuca tatarica ssp. Rulchellal, and whitetop fCardaria drabal are listed state-wide as <br />noxious weeds (Thornton et al., 1974). Only whitetop is a 'managed' noxious weed in Routt <br />County (Routt Co. Extension Agent, personal communication, 1993). Blue lettuce was observed <br />very sparingly in the the 1986 Reclaimed Areas, while whitetop was found in very small <br />amounts in the 1989 Reclaimed Areas. Buckhorn plantain (Plantaco lanceolatal and pennycress <br />(Thlasoi arvensel are both restricted noxious weeds in Colorado (Thornton et al., 1974); the <br />former is sparingly present at some locations in the reclaimed areas, while the latter is a <br />common species in the youngest reclaimed areas, and disappears within a few years. <br /> <br />33 <br />