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• the amounts of about 1 to 7 percent of total density in the reclaimed areas; while nowhere near <br />1989 levels, the presence of seedlings may reflect a response to greater moisture in 1991; this <br />may be responsible for the increase in density observed in 1992 which was maintained in 1993. <br />The slight increase in 1993 was mainly accounted for in an increase in mountain snowberry of <br />approximately 30 stems per acre, and 4 stems per acre of chokecherry. The 1994 decrease <br />was largely a decrease in the number of sagebrush; mountain snowberry remained nearly <br />constant. The small 1995 decrease may be an artifact of the fact that the sheer bulk of <br />herbage that constitutes an average herbaceous production of 4570 oven-dry pounds per acre <br />inevitably obscures and frustrates the most conscientious search of the ground for small <br />shrubs, especially snowberry. Of course, that bulk of overlying herbage that obscures such <br />small shrubs from view also prevents them from receiving direct sunlight, weakening them <br />incrementally. The below-ground competition between the lush herbaceous growth and shrubs <br />is likely to be fierce. These negative influences on shrubs may have caused some to die since <br />1994. Increases in herbaceous cover in 1997 probably coincide with some further losses due <br />to competition. <br />• The degree to which variations in the chance placement of sample points has affected these <br />averages over the years is not known, but within the Wadge Pasture, there are areas of local <br />abundance or scarcity. Random variation in sample placement could affect the relative degree <br />to which these extremes are sampled and could create apparent differences that do not reflect <br />changes in the true shrub population of the Wadge Pasture. <br />Species Diversity and Composition <br />Species density reflects the total number of species present (richness) in 100 square meters <br />one meter to either side of the 50m cover sample transects. Species density data are <br />summarized in Table 10 and graphically presented in Figure 4. As can be seen in Figure 4, as <br />well as from the data in Table 19, the total species density of the reference areas in 1997 is in <br />the range of 36.0 to 38.2 species/ 100 m2. The 1990 Reclaimed Area approached this range <br />with 29.8 species/ 100 mz. <br />In terms of native species density, the value was 15.5 species per 100 mZ in 1997, 13.5 to 19.7 <br />species per 100 mz in 1996, 10.0 to 18.0 species per 100 mZ in 1995, 15.7 to 19.9 species/ 100 <br />• m2 in 1994, 11.6 to 20.0 species per 100 mZ in 1993, 12.1 to 19.0 species per 100 m2 in 1992, <br />9.9 to 18.3 species per 100 m2 in 1991, and 9.5 to 18.9 species per 100 m2 in 1990. This <br />19 <br />