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<br />Discussion <br />The reasons for the results are not clear. The positive response of <br />shrubs and aspen to summer topsoil movement are probably due to some aspect <br />of the plant physiology. It should be recognized that the summer treatment <br />may not be truly representative of mid-summer topsoil movement. The summer <br />treatment did not occur until mid to late September. Although leaves on the <br />aspen were still green at this time, it is passible that initial stages of <br />dormancy had already begun. <br />Studies have shown„ th t roots from which most aspen regeneration <br />occurs are wi thi r, the top /coup i nches of topsoi 1 . I t i ~ al se, true that <br />the majority of the seeds f pl nts are found in the top/couple) inches of <br />topsoil. As a result one would expect that there would a faster plant <br />establishment on 2 lift treatments where a higher proportion of viable roots <br />and seed are close to the surface. However, the statistical analysis showed <br />no significant differences in overall shrub density between 1 and 2 lifts. <br />There wee owever, same significant interactions. If only dozed sites are <br />examined rub densities appear to be higher on 2 lift treatments than 1 <br />lift treatments. This ~1s not (true when rotocleared sites are examined. A <br />plausible explanation /`f-for why rotocleared treatments had higher shrub <br />densities, than dozed reatments may be competition from annual forbs <br />(weeds) and grasses. Although measurements were not takeJ~//visual <br />observations revealed that annual forbs and possibly grasses had mdJzi~ higher <br />densities on dazed treatments. This is reasonable because dozed sites had <br />much less mixing of the topsoil than rotocleared sites. Therefore one would <br />expect more viable root and seed material closer to the surface on dozed <br />sites. It appears that the mixing and thus greater depth had a greater <br />negative effect upon seed germination (forbs and weeds) than root <br />regeneration (shrubs), and that the reduced competition from forbs and <br />grasses on rotocleared sites gave the shrubs an advantage. <br />Fencing probably did not have much impact on shrub density the first <br />year because no vegetation was present during spring migration of big game <br />and shrub density data was collected in August prior to fall migration . <br />Significan browsing as well as desication of some sprouts was observed in <br />Septemb~r so differences between fenced and unfenced sites will be <br />evaluate tin the future. <br /> <br />