Laserfiche WebLink
<br />moderate woody plant density levels. Woody plants can be <br />established in the overall landscape, but when cover and <br />production most be met, these density levels are realistically <br />achieved at t:he levels proposed in Tab 22. SCC has collected <br />nine years of intensive vegetation monitoring data at the <br />Seneca II Mine that supports this conclusion. <br />Dry conditions in the region over the last five to seven years <br />have had some impact on woody plant density. However, the <br />most significant deterrent remain:> excessive herbaceous <br />competition. Observations of reclaimed sites with good woody <br />density leve}Ls either have a low cover of herbaceous species, <br />the herbaceous cover developed s1ow:Ly over time, or annual <br />precipitation was not limiting. The following illustrates how <br />critical reduced competition may be. Site 93-2 is a shrub <br />establishment: area at the Seneca II Mine planted with <br />seedlings in fall 1993 (see 1993 Annual Reclamation Report, <br />Seneca II Mi:ne). Topsoil was spread in summer 1993 and the <br />site was disl~:ed to control weeds prior to planting. One-half <br />of the plot was sprayed with OUST preemergent herbicide, while <br />the other half was untreated except for disking. In late July <br />1994, the plot was sampled to track preliminary survival. In <br />two 25-meter x 2-meter plots located in the disked/OUST <br />treatment, 34 woody plants with generally good vigor were <br />found. In two similar plots in the disked only side, a total <br />of only seven woody plants with low vigor were found. The • <br />portion of 'the plot treated with OUST had little or no <br />vegetation, ~rhile the disked only side had a heavy cover of <br />weeds. <br />The above i:lustrates the impact of competition on plant <br />establishment:. This corresponds to the theories of <br />competition a.nd niche. Species develop competitive mechanisms <br />and competing species cannot occup}~ the same niche. The <br />species with the competitive edge will occupy the available <br />niche. Reclamation procedures such as seeding and direct <br />hauling of topsoil impact niche availability and herbaceous <br />species, which have a greater (at least initially) competitive <br />edge, are established. This meets the regulatory requirements <br />of establishing an effective vegetative cover but has a <br />negative effect on woody plant establishment. In range <br />management, many areas that have become dominated by shrubs <br />are consider~ad to be in deteriorated. range condition (i.e., <br />reduced herbaceous competition). When herbaceous species are <br />gradually removed over time, those niches are occupied by <br />woody plant;. Quite simply, the establishment of even <br />moderate woocly density is an ecological hurdle which cannot be <br />overcome sol~aly by technology, particularly when additional <br />reclamation parameters of cover, production, and diversity <br />must also be met. Time and system dynamics must be <br />considered. <br />In a study b}~ Johnson (1979), it was found that a minimum of • <br />22 <br />