Grigg, A 2012, 'Adaptive rehabilitation management and a drying climate: unique challenges for Alcoa's bauxite mine rehabilitation in southwestern Australia', in AB Fourie & M Tibbett (eds), Mine Closure 2012: Proceedings of the Seventh International Conference on Mine Closure
, Australian Centre for Geomechanics, Perth, pp. 459-466, https://doi.org/10.36487/ACG_rep/1208_40_Grigg
Alcoa has been mining bauxite in Perth’s water supply catchments within the jarrah forest of southwest Australia since the late 1960s and has rehabilitated more than 15,000 ha to date. The current rehabilitation objective of restoring a sustainable jarrah forest ecosystem was implemented from 1988, utilising direct seeding of the local native tree species of jarrah (Eucalyptus marginata) and marri (Corymbia calophylla). Tree establishment densities were initially high, averaging 3,000 trees ha-1, but these have been reduced over time as an adaptive management response based on monitoring and feedback. The present day establishment target is 1,300 trees ha-1, with a maximum of 2,500 trees ha-1. Although tree densities meet past and current completion criteria agreed to by regulators, there is reluctance on the part of some government stakeholders to grant Certificates of Acceptance because of the higher water use characteristics of dense rehabilitation compared to the less dense forest it replaced. The issue has risen in prominence in recent years due to declining water yields into Perth’s water supply reservoirs, which are largely associated with a drying climate since the mid 1970s. While target tree establishment densities for future years of rehabilitation may be reviewed in renegotiated completion criteria, a legacy remains of older rehabilitation which is now regarded as over-dense. Alcoa believes that these areas may be treated by an initial cycle of thinning, which experimentation at the plot and whole-catchment scale has demonstrated: (i) increased catchment flows; (ii) potentially shortened crop rotations for future timber production; and (iii) benefits to forest conservation values including fauna. This paper describes the unique challenges faced by Alcoa and the rare example of large-scale post-establishment management of rehabilitation to address stakeholder concerns and to deliver improved rehabilitation outcomes.
Abbott, I. and Loneragan, O.W. (1983) Response of jarrah (Eucalyptus marginata) regrowth to thinning, Australian Forest Research, Vol. 13, pp. 217–229.
Batini, F. (2012) Dry times in the jarrah forest, Landscope (Summer 2011–12) Department of Environment and Conservation.
Cookson, W.R., O’Donnell, A.J., Grant, C.D., Grierson, P.F. and Murphy, D.V. (2008) Impact of ecosystem management on microbial community level physiological profiles of postmining forest rehabilitation, Microbial Ecology, Vol. 55, pp. 321–332.
Craig, M.D., Hobbs, R.J., Grigg, A.H., Garkaklis, M.J., Grant, C.D., Fleming, P.A. and Hardy, G.E.StJ. (2010) Does thinning and burning sites revegetated after bauxite mining improve habitat for terrestrial vertebrates? Restoration Ecology, Vol. 18, pp. 300‒310.
Crombie, D.S., Tippett, J.T. and Hill, T.C. (1988) Dawn water potential and root depth of trees and understorey species in south-western Australia, Australian Journal of Botany, Vol. 36, pp. 621–632.
Croton, J.T. and Reed, A.J. (2007) Hydrology and bauxite mining on the Darling Plateau, Restoration Ecology, Vol. 15, pp. S40–S47.
DEC (2007) Department of Environment and Conservation. Interim Guideline for the First Thinning of Bauxite Rehabilitation Areas Established After 1988 with Native Species in the Wungong Catchment, Department of Environment and Conservation SFM Interim Guideline No. 2.
Dell, B., Bartle, J.R. and Tacey, W.H. (1983) Root occupation and root channels of jarrah forest subsoils, Australian Journal of Botany, Vol. 31, pp. 615–627.
DoIR (2002) Department of Industry and Resources. Alcoa World Alumina Australia Darling Range bauxite mine rehabilitation completion criteria, Perth, Australia.
Elliot, P., Gardner, J., Allen, D. and Butcher, G. (1996) Completion criteria for Alcoa of Australia Limited’s bauxite mine rehabilitation, in 3rd International and 21st Annual Minerals Council of Australia Environmental Workshop, Newcastle, pp. 79–89.
Gardner, J.H. and Bell, D.T. (2007) Bauxite mining restoration by Alcoa World Alumina Australia in Western Australia: social, political, historical, and environmental contexts, Restoration Ecology, Vol. 15, pp. S3–S10.
Gentilli, J. (1989) Climate of the jarrah forest, in The Jarrah Forest: a complex Mediterranean ecosystem, B. Dell, J.J. Havel and N. Malajczuk (eds), Kluwer Academic Publishers, Dordrecht, The Netherlands, pp. 23–40.
Grant, C.D. (2003) Post-burn vegetation development of rehabilitated bauxite mines in Western Australia, Forest Ecology and Management, Vol. 186, pp. 147–157.
Grant, C.D. (2006) State-and-transition successional model for bauxite mining rehabilitation in the jarrah forest of Western Australia, Restoration Ecology, Vol. 14, pp. 28–37.
Grant, C.D. and Norman, M.A. (2006) Investigating thinning and burning operations in 10 to 13-year-old rehabilitated bauxite mines in the jarrah forest, Research Bulletin No. 35, Alcoa World Alumina Australia.
Grigg, A., Norman, M. and Grant, C. (2010) Prescribed burning of thinning slash in regrowth stands of jarrah (Eucalyptus marginata) following bauxite mining in south-west Australia, International Journal of Wildland Fire, Vol. 19, pp. 737–745.
Grigg, A.H. and Grant, C. (2009) Overstorey growth response to thinning, burning and fertiliser in 10–13-year-old rehabilitated jarrah (Eucalyptus marginata) forest after bauxite mining in south-western Australia, Australian Forestry, Vol. 72, pp. 80–86.
Hughes, J.D., Petrone, K.C. and Silberstein, R.P. (2012) Drought, groundwater storage and stream flow decline in southwestern Australia, Geophysical Research Letters, Vol. 39, L03408.
Kinal, J. and Stoneman, G.L. (2011) Hydrological impact of two intensities of timber harvest and associated silviculture in the jarrah forest in south-western Australia, Journal of Hydrology, Vol. 399, pp. 108–120.
Koch, J.M. (2007) Alcoa’s mining and restoration process in south western Australia, Restoration Ecology, Vol. 15, pp. S11–S16.
Koch, J.M. and Samsa, G.P. (2007) Restoring jarrah forest trees after bauxite mining in Western Australia, Restoration Ecology, Vol. 15, pp. S17–S25.
Koch, J.M. and Ward, S.C. (2005) Thirteen year growth of jarrah (Eucalyptus marginata) on rehabilitated bauxite-mines in south-western Australia, Australian Forestry, Vol. 68, pp. 176–185.
Macfarlane, C., Bond, C., White, D.A., Grigg, A.H., Ogden, G.N. and Silberstein, R. (2010a) Transpiration and hydraulic traits of old and regrowth eucalypt forest in southwestern Australia, Forest Ecology and Management, Vol. 260, pp. 96–105.
Macfarlane, C., Lardner, T., Patterson, K. and Grigg, A. (2010b) A new model for predicting understorey leaf area from biomass in eucalypt forest to test the ecohydrological equilibrium theory, Methods in Ecology and Evolution, Vol. 1, pp. 371–379.
McChesney, C.J., Koch, J.M. and Bell, D.T. (1995) Jarrah forest restoration in Western Australia: canopy and topographic effects, Restoration Ecology, Vol. 3, pp. 105–110.
Mu, X.M., Zhang, X.Q., Gao, P. and Wang, F. (2010) Theory of double mass curves and its application in hydrology and meteorology, Journal of China Hydrology, Vol. 30, pp. 47–51.
Petrone, K.C., Hughes, J.D., Van Neil, T.G. and Silberstein, R.P. (2010) Streamflow decline in southwestern Australia, 1950–2008, Geophysical Research Letters, Vol. 37, L11401.
Ruprecht, J.K. and Stoneman, G.L. (1993) Water yield issues in the jarrah forest of south-western Australia, Journal of Hydrology, Vol. 150, pp. 369–391.
Schofield, N.J., Stoneman, G.L. and Loh, I.C. (1989) Hydrology of the jarrah forest, in The Jarrah Forest: a complex Mediterranean ecosystem, B. Dell, J.J. Havel and N. Malajczuk (eds), Kluwer Academic Publishers, Dordrecht, The Netherlands, pp. 179‒201.
Stoneman, G.L. (1993) Hydrological response to thinning a small jarrah (Eucalyptus marginata) forest catchment, Journal of Hydrology, Vol. 150, pp. 393–407.
Stoneman, G.L. and Schofield, N.J. (1989) Silviculture for water production in jarrah forest of Western Australia: an evaluation, Forest Ecology and Management, Vol. 27, pp. 273–293.
Ward, S.C. and Koch, J.M. (1995) Early growth of jarrah (Eucalyptus marginata Donn ex Smith) on rehabilitated bauxite minesites in south-west Australia, Australian Forestry, Vol. 58, pp. 65–71.
Water Corporation (2005) Wungong Catchment Environment and Water Management Project, Water Corporation, Leederville, Western Australia.