HOW CAN PLANT PROPAGATION IMPROVE THE ENVIRONMENTAL PERFORMANCE OF AN INTEGRATED BAUXITE AND ALUMINA OPERATION?

Alcoa of Australia operates two bauxite mines and three alumina refineries (plus their associated farmlands) in Western Australia. Plant propagation research and application by Alcoa’s Marrinup Nursery contributed to improving their environmental performance. The principle concept was to use a wide range of plant propagation technologies to enhance the biodiversity of restored or conserved native vegetation. A second guiding concept was ensuring the resilience of this vegetation. Native vegetation in Western Australia has to cope with regular disturbance by an annual dry season and irregular disturbance from fire and disease. Any revegetation has to be capable of surviving these disturbances.

Studying the wild biology of each species was critical preliminary research to enable propagation success. Many of the desired species had never been grown before; with little known beyond their taxonomic naming. Developing large scale plant production methods then required detailed and lengthy propagation research.

Since 1980 more than 32 million plants have been produced and planted to improve: (1) bauxite mine rehabilitation biodiversity; (2) refinery farmlands rare plant populations; (3) refinery bauxite residue revegetation; (4) refinery clay pit revegetation; (5) goldmine tailings revegetation; (6) regional landcare activities; and (7) to reduce the impact of a regional plant disease. More than 27 tonnes of seedmix was broadcast on bauxite mine rehabilitation. Furthermore, horticultural research consultation improved bauxite residue rehabilitation and farmlands vegetation.

The technologies used to achieve these outcomes included: (1) seedling and cuttings production; (2) tissue culture; (3) embryo rescue; (4) fern production by gametophyte culture; (5) artificial seed production; (6) cryopreservation; (7) provenance genetics assessment of species used in mine rehabilitation; (8) seed-orchards; and, most importantly, (9) species correct seed mixes.

Selected examples of how Alcoa’s Marrinup Nursery has applied propagation and research will be described. The information gained during the last 34 years has been freely shared with our neighbours, landholders, schools, technical colleges, universities, other mining and refining operations, government departments and environmental agencies at local, national and international levels. Alcoa’s Marrinup Nursery has demonstrated that small nursery operations can generate significant and lasting environmental improvements for mining and mineral refining operations.