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Seed mixes used on all reclaimed areas at the Kerr Mine contain high seeding rates for shrub <br />seeds (Appendix 3, Tables 20 and 21) and are designed to give shrubs an early competitive <br />advantage over grasses and (orbs. This advantage is expected to decrease as the time from <br />reclamation becomes greater. Consequently, shrub density counts that are taken in the first few <br />years after reclamation activities may be higher than those taken in the same areas in <br />subsequent years. Conversely, if climatic conditions adversely affect shrub establishment in the <br />year of seeding, relatively low shrub densities may be noted in the first years following <br />reclamation. As the time from reclamation becomes greater, these densities may increase. At <br />some period in time after an area has been seeded, it is expected that the shrub densities in <br />reclaimed areas will approach "equilibrium". This point of equilibrium will represent the true state <br />of competition between shrubs, grasses, and (orbs. <br />The Pre-1986 Reclamation Area represents an amalgam of areas reclaimed between 1979 and <br />1986. Shrub density in this united area has been monitored in previous years and a range of <br />shrub density estimates have been produced. Some of this variation may be attributed to the <br />equilibration period that followed reclamation. It is also possible that some of this variation in <br />shrub counts from multiple should be related to small sample sizes and to inconsistency in what <br />was being counted as shrubs. In 1996, a density of 1264 shrubs per acre was reported for the <br />Pre-1986 Reclamation Area (Rocky Mountain Reclamation, 1996). This estimate is quite close to <br />the present mean of 1299 shrubs per acre. Assuming that some of the higher and lower <br />estimates of shrub density over the years were in fact real, the present mean of 1299 stems per <br />acre may reflect a reasonable estimate of the present niche for shrubs. <br />In the Pre-1986 Reclamation Area, the 1999 estimate of 1299 shrubs per acre fails to meet both <br />the existing permit requirement of 1350 shrubs per acre. If subshrubs were to be included, then <br />the current estimate of 1474 shrubs and subshrubs per acre is greater than 90 percent of the <br />standard (1350 shrubs per acre) and the reclamation would be deemed successful. However, it is <br />understood that subshrubs are to be ignored in conparisons to this standard. <br />The 1995 Reclamation Area and the 1996 Reclamation Area were seeded in subsequent years <br />using an identical seed mix. Current shrub densities in the 1995 Reclamation Area are 7114 <br />stems per acre and in the 1996 Reclamation Area are 2810 stems per acre. This marked <br />variation may be related to the heavy precipitation enjoyed in 1995. Shrub densities in both the <br />1995 and the 1996 Reclamation areas meet the existing permit requirement of 1500 stems per <br />acre. <br />Species Diversity and Composition <br />The species diversity standard established for the Kerr Mine is based on cover and requires that <br />the four dominant species comprise no more than 83% of relative vegetation cover and that no <br />single species comprise more than 40% of the relative vegetation cover. At least one of the four <br />dominant species shall be either a fort or a shrub. The dominant four species for each <br />reclamation and reference area are illustrated in Figure 6. All reclamation areas are in <br />compliance with this standard. <br />Evaluation of species richness is another method of examining species diversity. Species <br />density reflects the total number of species present (richness) in 1 meter on either side of the 50 <br />m cover sample transects (50 m X 2 m = 100 square meters). Species density data are <br />summarized in Table 18 and represented graphically in Figure 4. Total species densities in the <br />reference areas ranged between 14.5 and 19.9 species/100 square meters. Less than one <br />percent of species in the reference areas are introduced. The Pre-1986 Reclamation Area, in <br />which more than 70 percent of all species were native, most closely matched this ratio. Native <br />species made up approximately 60 percent of the species composition in each of the younger, <br />1995 Reclamation Area and 1996 Reclamation Area, reclamation units. Species density was <br />greater in these younger reclamation areas than in the older, Pre-1986 Reclamation Area; but, <br />this difference was largely attributable to the presence of introduced annual species. Total <br />17 <br />