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• Canopy Cover. Canopy cover was monitored by systematically placing five 0.5 meter X 0.5 <br />meter quadrats at five meter intervals along the right side of the transect tape. Canopy of grasses <br />and forbs were recorded by life form. Forbs, mainly thistle, (Cirsium sp.) aze colonizing the <br />topsoil treatment to a greater extent than the no-topsoil treatment. Colonization of the topsoil <br />treatment is likely related to the finer soil texture, higher organic matter, and greater nutrient <br />levels present. Thistle is developing into a serious weed problem on this plot and is typical of the <br />current situation on several topsoiled sites at the mine. Grass coverage was very low on the site. <br />The Oust herbicide application appeazs to be having a substantial and lasting effect on the <br />establishment of grasses. <br />Table 23. Comparison of canopy cover between Topsoil and No-Topsoil Treatments. <br />Species Topsoil <br />Treatment No-Topsoil <br />Treatment <br />Forb Canopy Cover 11.5% 3.4% <br />Grass Canopy Cover 0.0% 0.0% <br />Conclusions <br />Overall, topsoil application appears to negatively impact the establishment of shrubs based upon <br />• two years of monitoring. Survival on the no-topsoil treatment is substantially higher than the <br />topsoil treatment. When vigor was assessed, plants on the topsoil treatment have tended to <br />decline in height while those on the no-topsoil treatment have increased slightly. The differences <br />in survival and height aze most likely accounted for by invasion of Canada Thistle and increased <br />plant competition on the finer textured topsoil medium. In addition, shrub species may be better <br />able to utilize habitat with rocky substrates by allowing for deeper root penetration and better use <br />of lower moisture levels. Rooting depth will be assessed during the final yeaz of the study to <br />investigate this possibility. As for the performance of species, Gambel's Oak and Chokecherry <br />consistently survive at higher rates than Serviceberry. Gambel's Oak appeazs to have an <br />excellent ability to resprout from damaged shoots. Final field monitoring will occur during fall <br />of 1998. <br />• 29 <br />