Thesis: Investigation of microbiological activities and resulting nutrient fluxes impacting the use of wood waste in rehabilitating jarrah forest mine sites
Significant quantities of wood waste are generated during land clearing operations at the onset of the bauxite mining process. State forest areas scheduled for mining operations are first cleared of economically useable timber. The residual woody wastes are “snipped” to manageable size materials that can be relocated by earth moving equipment during topsoil removal mining operations. It is understood that approximately 80,000 tonnes of woody waste are generated per year under the current level of mining operations. Presently the most economic method of disposing this woody waste is by burning.
Alcoa has determined that chipping wood wastes into mulch is not economically viable as a sellable product, nor is it likely to be viable for application onto rehabilitated mine sites. In 1997, an experiment was undertaken by Alcoa to assess methodologies for managing wood waste debris by methods other than burn-off. Un-chipped wood wastes presently generated by mining operations are considerably more heterogeneous with regards to physical composition than that used for the test study initiated in 1997; however the floristic composition is relatively identical.
In order to study the biochemical processes that take place, especially considering the sequestration of carbon and mineralisation of nutrients, with the infusion of jarrah forest mulch into a rehabilitation system, this waste by-product will be tested under laboratory conditions.
Why my research is important
This study aims to understand the significance of adding concentrations of wood waste to areas scheduled for rehabilitation and to better understand what fertilisation may be able to counteract the limiting of available nutrients by adding wood wastes. The research will seek to gain a better understanding of the microbial degradation processes with the potential view to understand what nutrient deficiencies may need to be addressed in future rehabilitation operations to successfully use woody waste to augment mine site rehabilitation practices. Success in this endeavour will prevent the generation of atmospheric carbon caused by eliminating the practice of bun-off.
While a significant number of studies would be necessary to fully answer the question posed, the research project will enable a realistic understanding of the microbial activity and mineralisation processes that take place under laboratory conditions using the actual waste of concern.