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Shrub establishment at Seneca mine has been intermediate relative to Trapper and Colowyo mines. The <br />decline or elimination of established shrubs in unfenced plots at Seneca between 2002 and 2004 will need to <br />be followed over time to see if it is a real trend or an artifact of sampling (the low density of shrubs causes <br />variance to be high). While shrub density is relatively low at Seneca, the shrubs are very robust at this site as <br />indicated by height measures (Figure 6 and Table 9) due to the fact that transplants were used. Shrub <br />tubelings planted in some of the plots continue to show high survival in 2004 (Table 16) and many flowering <br />and fruiting shrubs were observed at this time. Among all of the mines, Seneca was the only location where <br />the tall shrub species such as serviceberry and chokecherry became established. These species did not <br />establish well from seeding on the other mines, whereas they did establish from the transplants at Seneca. The <br />fall 2000 seeding at the Seneca mine appears to have been somewhat successful. Many of the seeded species <br />were encountered in some of the plots at Seneca in 2004 (Table 14). Invasive weeds such as yellow sweet <br />clover and Japanese brome continue to dominate most plots at Seneca. Russian thistle, which was a site <br />dominant in 2003, was not found in 2004. It is likely that yellow sweet clover will not be a persistent problem, <br />but Japanese brome and cheatgrass are of concern. Fall application of herbicides, as is being done at the <br />mines, should help to reduce the threat from these species if they do become a serious problem in the <br />demonstration plots. <br />Figure 6. Robust serviceberry transplants inside the fenced area at Seneca Mine in 2004. <br />The fence treatment at the mines appears to have generally resulted in increased shrub density, average height <br />and cover (Table 9). This is especially apparent for preferred browse species such as bitterbrush (Tables 10 - <br />15). Since deer, elk and antelope are known to browse shrub species, this is the expected result. However, <br />many of the unfenced plots have modest numbers of shrubs that could survive in the long-term. Since <br />browsing is an episodic phenomenon in these habitats, it is likely that the fencing treatment will become more <br />significant with increasing time as the chances for destructive browsing events increase with time. Continued <br />monitoring of the plots on a biennial or triennial basis will be needed to gauge the true impact of fencing on <br />shrub establishment over a more ecologically-relevant time frame. <br />The effect of topsoil depth on shrub establishment is difficult to assess at Trapper mine due to low shrub <br />numbers and difficult to assess at Seneca due to uneven planting of shrub species across treatment plots. <br />However, at Colowyo mine, where shrub establishment was initially high, the intermediate topsoil depth of 15 <br />cm (plots 2 and 3) appears to have resulted in the best initial shrub establishment (Table 9). While the no <br />topsoil plots (plots 4 and 5) at Colowyo had the poorest initial shrub establishment, these plots have shown <br />the greatest increases in shrub establishment in recent years. These results illustrate the importance of <br />continued monitoring of the plots in order to determine the effects of topsoil depth on shrub community <br />development. <br />The individual effects of other treatments such as seed mix, seeding method, surface manipulations and <br />mycorrhiza inoculation are difficult to assess due to the lack of a complete factorial design. In terms of shrub <br />establishment, some observations that can be made at this time based upon results from Colowyo are that <br />surface manipulations and the use of a seed mix containing lowcompetitive native forbs lacking grasses (plot <br />2) can result in increased shrub establishment and cover (Table 9). Shrub cover in this plot containing these <br />treatments was 16.5% inside the fence and 13.9% outside the fence in 2004. This plot represents the best <br />results for all of the mines and treatments in the study. The effects of the mycorrhiza inoculation treatment <br />cannot be evaluated at this time since this treatment was only conducted at Trapper mine and shrub numbers <br />are still to low to allow for adequate sampling. <br />In summary, the following conclusions can be drawn from the shrub establishment demonstration <br />plots to date: <br />• The use of grass species with relatively low competitive ability, as used in the demonstration plots, <br />appears to have resulted in unusually good shrub establishment.