Catalog Home Page

Revegetation of gold residues in the eastern jarrah forest in the south-west of western Australia

McGrath, W., Bell, R.ORCID: 0000-0002-7756-3755, Jasper, D.A., Hinz, C., Struthers, I., Eastham, J. and McNeil, P. (2003) Revegetation of gold residues in the eastern jarrah forest in the south-west of western Australia. In: 2003 National Meeting of the American Society of Mining and Reclamation and The 9th Billings Land Reclamation Symposium, 3 - 6 June, Billings MT, USA p. 513.

[img]
Preview
PDF - Published Version
Download (297kB)
Free to read: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&so...
*No subscription required

Abstract

Revegetation of mine residues (tailings) is an important aspect of rehabilitation after mining, and represents a substantial investment. Therefore it is important to increase our understanding of all aspects of re-establishing a sustainable vegetation community on these materials. We report here on a multi-disciplinary, collaborative research program, focusing on vegetation establishment, soil development, and water-balance modeling on a large residue revegetation experiment.

The study focused on gold residues produced at the Boddington Gold Mine (BGM) and Hedges Gold Mine (HGM), in the south-west of Australia. The residue storage areas will be rehabilitated once no longer required, but revegetation may be hampered by the alkaline, saline, and sodic properties of the residue. A large field experiment was established to examine soil amendments and capping strategies. The treatments were three depths of gravel-rich subsoil (0 cm, 15 cm, and 30 cm) overlying residue treated with gypsum (30 t/ha). All plots subsequently received an application of topsoil (10 cm). The plots were established in 1999 with species from the local jarrah (Eucalyptus marginata Donn. ex Smith) forest, or salt- and waterlogging-tolerant native species.

Ten months after application, gypsum had contributed to a decrease in residue pH and salinity. By March 2000, approximately 90% of the directly seeded species had emerged and survived, and 100% of transplanted seedlings had survived. Applying gravel subsoil in addition to topsoil did not improve plant growth in the first two years. In fact, aboveground biomass production was higher, from 4 to 8.5 t/ha/yr, in the absence of a gravel subsoil. However, in the third growing season, this trend was less apparent.

Plant roots were found to grow into the residue, preferentially following shrinkage cracks and exploring coarser-textured layers. Vigorous plant and root growth, and thus high plant water use, has resulted in substantial drying of the residue profile. On-going studies are examining water and salt movement through these profiles and long-term plant performance. At the same time, an overall model is being developed to predict the net water balance if the whole residue area was vegetated.

Item Type: Conference Paper
Murdoch Affiliation: School of Environmental Science
Publisher: ASMR
URI: http://researchrepository.murdoch.edu.au/id/eprint/18123
Item Control Page Item Control Page

Downloads

Downloads per month over past year