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Tailings material is known to present a challenging growth environment as it presents several ecologically
hostile characteristics. Although vegetation is initially established through active rehabilitation input,
questions remain about spontaneous recolonisation potential of the area over time. The influence of soil
physical properties and more specifically dispersivity, on soil-seed contact interface (safe sites) is still largely
unknown for tailings dams which are rehabilitated without reshaping or a topsoil cover. Conventional
grassing limits erosion only by 55% on gold tailings dams with slope gradients of more that 30°, which raises
questions about the effectiveness and self-propagation of vegetation on tailings. The objectives of this study
were to quantify the physical nature of gold tailings material in terms of its dispersivity and to report on the
results of reconstructed soil profiles with improved dispersivity status. The relationship between dispersivity
and the establishment of native grass seedlings were further investigated. This research adds to the
sustainability debate of directly revegetated tailings dams and the degree to which reconstructed soil systems
can sustain self-propagating and functioning ecosystems. It is therefore hypothesised that the inherent
susceptibility of the tailings medium to erosion could substantially affect spontaneous vegetation
establishment and will have an impact on seedling survival and inevitably successionary development if the
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The Effect of the Dispersive Nature of Tailings on Seedling Establishment and Survival S.J. van Wyk, L. van Rensburg
402 Mine Closure 2006, Perth, Australia
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Ecosystem Reconstruction and Pedogenesis
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