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promoting vegetation productivity. But, an increasing realization that this <br />maximization of productivity has resulted in a minimization of diversity (at least beta <br />diversity) and severe damage to soil microbial populations has brought into question <br />past soil handling practices. <br />With increasing scrutiny on species diversity, several studies have evaluated the affects <br />of soil depth on diversity. The research strongly suggests that soil homogeneity and <br />lack of landscape or habitat diversity results in vegetation stands generally populated <br />with cool - season aggressive grasses with few forbs or shrubs (Allen, 1995; Munshower, <br />2000; Prodgers and Keck, 1996; Romig and Clark, 2000). In the semi -arid west, greater <br />forb and shrub species diversity was favored at topdressing depths between 9 and 12 <br />inches with fewer species found at the shallow depth ( <9 ") and deeper depth ( >15 ") <br />(Buchanan et al., 1999). These observations are supported in the native landscape when <br />one considers the vegetation communities and compares them to the soil depths <br />occurring at various landscape positions and slope classes. <br />Spatial redistribution of topsoils and subsoils is key to creating diversity of vegetation <br />community types. Lands that receive topsoil favor the establishment of grasslands. <br />Graded areas topdressed with suitable subsoil or spoil materials (i.e. no segregated <br />topsoil) favor the establishment woody plant species. Sencindiver and Ammons (2000) <br />thoroughly discuss the soil genesis and classification of soils formed on landscapes <br />altered by human activities such as mining. These minesoils, many of which were <br />leveled spoil materials, are undergoing relatively rapid soil formation processes, <br />including accumulation of organic matter, horizon development and the development <br />of soil structure. Establishment of native shrubs is particularly successful on selectively <br />handled subsoil and spoil materials, especially those with higher rock contents <br />(Buchanan et al., 1999). The key to successfully establishing plant species and <br />vegetation community diversity within reclaimed lands is to create a landscape with a <br />variety of aspects and slopes topdressed with appropriate soil types and depths. <br />Appendix G 5 07/01/02 <br />