Original Articles

Microbial community function and structure on coal mine discard under rehabilitation

Published in: South African Journal of Plant and Soil
Volume 23, issue 2, 2006 , pages: 105–112
DOI: 10.1080/02571862.2006.10634739
Author(s): S. Claassens, South Africa, K.J. Riedel, South Africa, L. Van Rensburg, South Africa, J.J. Bezuidenhout, South Africa, P.J. Jansen van Rensburg, South Africa


The rehabilitation of coal mine discard is problematic, especially since the lack of measures to evaluate the success of rehabilitation in terms of the self-sustainability of soil ecosystems established on these sites. In this study, the potential for using microbial community function and structure as such a measure was investigated using enzymatic assays (dehydrogenase, ß-glucosidase, urease and acid and alkaline phosphatase) and signature lipid biomarkers (PLFAs). Samples from seven coal discard sites in South Africa currently under rehabilitation, were investigated and the relationship between soil properties, vegetation cover and microbial properties analysed using PCA and RDA ordination techniques. Although the discard sites had different rehabilitation ages (one to eight years), no statistically significant differences existed between these sites based on physical and chemical characteristics. Differentiation was possible based on enzymatic activities and PLFA profiles. Sites with relatively higher vegetation cover and organic carbon content had a positive association with enzymatic activities and microbial biomass. Organic carbon content correlated significantly with ß-glucosidase (r = 0.80, P<0.05), urease (r = 0.96, P<0.05), acid phosphatase (r = 0.76, P<0.05), dehydrogenase (r = 0.69, P<0.10) and microbial biomass (r = 0.73, P<0.10). The characterisation of microbial community function and structure holds potential for evaluating rehabilitation progress on mine discard sites.

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