R. John Raison

A common view of the opportunities, challenges, and research actions for Pongamia in Australia.

Interest in biofuels is increasing in Australia due to volatile and rising oil prices, the need to reduce GHG emissions, and the recent introduction of a price on carbon. The seeds of Pongamia (Millettia pinnata) contain oils rich in C18:1 fatty acid, making it useful for the manufacture of biodiesel and other liquid fuels. Preliminary assessments of growth and seed yield in Australia have been promising. However, there is a pressing need to synthesise practical experience and existing fragmented research and to use this to underpin a well-founded and co-ordinated research strategy to support industry development, including better management of the risks associated with investment. This comprehensive review identifies opportunities for Pongamia in Australia and provides a snapshot of what is already known and the risks, uncertainties, and challenges based on published research, expert knowledge, and industry experience. We conclude that whilst there are major gaps in fundamental understanding of the limitations to growth of Pongamia in Australia, there is sufficient evidence indicating the potential of Pongamia as a feedstock for production of biofuel to warrant investment into a structured research and development program over the next decade. We identify ten critical research elements and propose a comprehensive research approach that links molecular level genetic research, paddock scale agronomic studies, landscape scale investigations, and new production systems and value chains into a range of aspects of sustainability.

Biomass for aviation fuel production in the Fitzroy Basin, Queensland: a preliminary assessment of native and plantation forest potential

Summary This scoping study assesses the contribution that woody biomass could make to feedstock supply for an aviation biofuel industry in Queensland. The inland 600–900 mm rainfall zone, including the Fitzroy Basin region, is identified as an area that is particularly worthy of closer study as it has potential for supply of woody biomass from existing native regrowth (brigalow and other species) as well as from new plantings. New analyses carried out for this study of Corymbia citriodora subsp. variegata trials suggest biomass plantings could produce harvestable yield of aboveground dry mass of about 85 t ha−1 over a 10-year rotation at relatively low-rainfall (600–750 mm mean annual precipitation) sites and about 115 t ha−1 at medium-rainfall (750–900 mm) sites. Estimates of productivity for native regrowth suggest potential productivity should be around 40 t ha−1 during the initial decade after clearing when systems are managed for bioenergy rather than grazing. In this paper, potential production systems are described, and sustainability issues are briefly considered. It is concluded that more detailed studies focused particularly on biomass production would be worthwhile, and further research requirements are briefly discussed.

Possible Impacts of Climate Change on Forest Soil Health

A changing climate could induce a myriad of changes in forests and thus in forest soil health at the global scale, as a consequence of both direct and indirect impacts. The direct effects include increased temperature and atmospheric concentration of CO2, changes in precipitation and the frequency and severity of extreme climatic events such as heatwaves, droughts, storms (rain, ice and wind) and frosts. The indirect effects can be very significant and rapid, and are mediated, in particular, by changes in the frequency and impacts of outbreaks of pests and pathogens, changes in fire regimes and changes in vegetation growth and species composition (including from invasive species), which affect litter inputs and many associated soil processes. Changes in soil health will be location specific – determined by very complex interactions between climate, terrain, vegetation and soil type. Significant soil change can occur within days following severe disturbances, but may also take many decades when associated with succession of vegetation. Soil change can also be either moderated or magnified by management responses to the risks or opportunities created by climate change. While many important soil properties and processes can be affected, soil organic matter is a key variable affecting the health and fertility of forest soils that is very sensitive to both climate change and forest management.