Ecosystem development on seven rehabilitated discard dumps

Abstract

To successfully rehabilitate disturbed land the initial input of resources and the maintenance afterwards must be an integrated process. The achievement of a good vegetation basal, crown and organic ground cover can be regarded as one of the central aims of this process. This study evaluated the role of current rehabilitation practices to ensure a sustainable vegetation cover in terms of topsoil nutrient status, topsoil thickness, slope steepness, topsoil texture and the use of grazing as maintenance practice. The study was conducted on seven rehabilitated discard dumps situated on the Mpumalanga Highveld, South Africa. Vegetation was assessed according to its composition, basal, crown and ground cover. In general the neutral to slightly alkaline soil pH and low salinity indicate that the topsoil on the dumps is conducive to vegetation growth. The grass species Digitaria eriantha, Eragrostis curvula, Chloris gayana and Eragrostis plana contributed most to basal cover. Grazing of rehabilitated vegetation decreased crown cover but increased ground cover. Grazing intensity was a significant factor to explain changes in ground cover. Differences in composition were also related to soil depth, topsoil texture and soil fertility.