Bauxite Mining Restoration by Alcoa World Alumina Australia in Western Australia: Social, Political, Historical, and Environmental Contexts

摘要

Alcoa World Alumina Australia mines bauxite under lease agreements with the Government of Western Australia. The leases lie in the Darling Range to the east of Perth, the capital and major population center. In addition to bauxite and other mineral ores, the Darling Range is a major potable water source and harbors a species-rich forest dominated by Jarrah (Eucalyptus marginata), a significant commercial timber. Conservation and recreation are important land uses in the region. Social and political pressures have led to stringent governmental requirements for restoration. In addition, a summer drought period, a soil deficient in most nutrients, water management challenges, an introduced disease, caused by Phytophthora cinnamomi Rands, and a post-mining ecosystem that must be conducive to the prescribed burning management of the region pose significant challenges to successful restoration. Alcoa presently mines and restores approximately 550 ha per annum. Although the “footprint” at the end of the life of the mining operations represents only about 4% of the total forest estate, Alcoa is committed to restoring the forest values of the region of all lands impacted by mining. The major objective of restoration is to enhance or maintain forest values by restoring habitat and structural characteristics of the native forest environment. Completion criteria for Alcoa’s mine restoration have been developed. The original Alcoa mine at Jarrahdale has been rehabilitated, and in 2005, a 975-ha area received a “certificate of completion” and was returned to the management control of the State of Western Australia.