1987-12-01_PERMIT FILE - C1981017 (290)

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in ngRmounwnioiL contribute 8.0 percent and 6.9 percent relative cover, respectively, averaged over all plots. The most abundant forb, in terms of relative cover, is cicer milkvetch, with 8 percent relative cover averaged over all plots. Blue aster and ox-eye daisy contribute 4.4 percent and 4.7 percent relative cover,respectively, averaged over all plots. Table 3 shows vegetation production data. These data are summarized in Table 4. Average production over all plots is 10.8 g 0.25m-2 (oven-dry). The highest producing species is orchardgrass at 3.3 g 0.25m-2 (oven-dry), averaged over all plots. Bromar biorrie and orchardgrass contribute 1.4 g 0.25m-2 (oven-dry) and 1.3 g 0.25m-2 (oven- dry) total production, respectively, averaged over all plots. Cicer milkvetch and blue aster contribute 0.7 g 0.25m-2 (oven-dry) and 0.6 g 0.25m-2 (oven-dry) total produc- tion,respectively,averaged over all plots. No shrubs were encountered in either transect or quadrat sampling. One small rose (Rosa sp.) seedling was observed in one plot. 0ualiitative Observations The,spoil material appears suitable as a plant growth medium. Moisture is not limiting. Growth of introduced species, in particular, is enhanced by fertilization. Long term maintenance fertilization may be required for these species to survive. The lack of long term fertilization would probably favor native species adapted to low fertility environments. Another significant limitation to long term growth and survival is the shore: growing season. Plant species must either be able to reproduce vegetatively or be able to produce seed within a short season. It is too early to tell whether this will be a limitation for some species growing on the plots. By far the most limiting factor in successfully revegetating these sites is the steep slopes. Surface instability due to sloughing and creeping can prevent new plant establishment. This effect is apparent at all three plot locations, where the upper portions of the plots exhibit significantly greater vegetation cover than the lower parts. It is not known to what extent this may also be due to ineffective seed coverage on the lower parts of plots when the plots were seeded. Although such structures are never permanent, berms, furrows or benches may provide enough temporary relief from surface instability to allow more uniform initial establishment from top to bottom. Revegetation of these slopes might further be enhanced by planting live seedlings or cuttings of woody plants.