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Indigenous fire knowledge offers significant benefits for ecosystem management and human livelihoods, but is threatened worldwide because of disruption of customary practices. In Australia, the historical prevalence and characteristics of Aboriginal burning are intensely debated, including arguments that Aboriginal burning was frequent across the continent. Frequent burning is supported by contemporary Aboriginal knowledge and practice in some regions, but in southern Australia evidence is typically limited to historical and ecological records. Towards characterizing Aboriginal fire regimes in southern Australia, we collaborated with Ngadju people from the globally significant Great Western Woodlands in south-western Australia to document their fire knowledge. We used workshops, site visits, interviews and occupation mapping to aid knowledge sharing. Consistent with the established significance of Aboriginal fire in Australia, planned fires were important in Ngadju daily life and land management. However, Ngadju use of fire was characterized by its selectivity rather than its ubiquity. Specifically, Ngadju described only highly targeted planned burning across extensive eucalypt woodlands and sandplain shrublands. By contrast, frequent planned burning was described for resource-rich landscape elements of more restricted extent (granite outcrop vegetation, grasslands and coastal scrub). Overall, Ngadju fires are likely to have resulted in subtle but purposeful direct effects on the vegetation and biota. However the extent to which they collectively constrained large, intense wildfires remains unclear. Ngadju demonstrated a predictive knowledge of the ecological consequences of burning, including attention to fine-scale needs of target organisms, and application of diverse fire regimes. These are consistent with the recently proposed concept that Aboriginal burning was guided by ‘templates’ targeting different resources, although diverse regimes predominantly reflect edaphically driven vegetation patterns rather than template-driven use of fire to create resource diversity. We conclude that Ngadju fire knowledge fills an important gap in understanding Aboriginal fire regimes in southern Australia, highlighting a novel balance between frequent and constrained use of fire.

This paper provides spatial estimates of potentially available biomass for bioenergy in Australia in 2010, 2030 and 2050 (under clearly stated assumptions) for the following biomass sources: crop stubble, native grasses, pulpwood and residues (created either during forest harvesting or wood processing) from plantations and native forests, bagasse, organic municipal solid waste and new short-rotation tree crops. For each biomass type, we estimated annual potential availability at the finest scale possible with readily accessible data, and then aggregated to make estimates for each of 60 Statistical Divisions (administrative areas) across Australia. The potentially available lignocellulosic biomass is estimated at approximately 80 Mt per year, with the major contributors of crop stubble (27.7 Mt per year), grasses (19.7 Mt per year) and forest plantations (10.9 Mt per year). Over the next 20–40 years, total potentially available biomass could increase to 100–115 Mt per year, with new plantings of short-rotation trees being the major source of the increase (14.7 Mt per year by 2030 and 29.3 Mt per year by 2050). We exclude oilseeds, algae and ‘regrowth’, that is woody vegetation naturally regenerating on previously cleared land, which may be important in several regions of Australia (Australian Forestry 77, 2014, 1; Global Change Biology Bioenergy 7, 2015, 497). We briefly discuss some of the challenges to providing a reliable and sustainable supply of the large amounts of biomass required to build a bioenergy industry of significant scale. More detailed regional analyses, including of the costs of delivered biomass, logistics and economics of harvest, transport and storage, competing markets for biomass and a full assessment of the sustainability of production are needed to underpin investment in specific conversion facilities (e.g. Opportunities for forest bioenergy: An assessment of the environmental and economic opportunities and constraints associated with bioenergy production from biomass resources in two prospective regions of Australia, 2011a).

The aviation industry in Australia has aspirations to supply 5% of its domestic fuel use from biomass by 2020. The majority of available sources of biomass in Australia are lignocellulosic, and novel production systems that integrate existing land uses with energy production systems could have many benefits to growers and regions through enterprise diversification. This study assessed the operational and economic factors associated with lignocellulosic biomass supply for production of sustainable aviation fuel in a case study region in central Queensland, Australia. We examined the potential for biomass supply from native grasses, naturally regenerating woody vegetation (regrowth), and newly established plantings of short rotation trees (SRT) from the Fitzroy Catchment (14.2 million hectares). We outline a hypothetical industry scale-up strategy that achieves a production target of 470 ML of aviation fuel within a 25 year timeframe. We assess the amount of biomass required to support the scale-up strategy and the associated costs of supply to meet production targets during the scale-up. Approximately 5 million tonnes of biomass per year are required to support full production capacity after 25 years; 1.1 millions of land is required to be managed to supply this quantum of biomass. A preliminary assessment of the cost of supply for each feedstock indicates that grasses are most expensive at ~$142 t −1 due to relatively low biomass potentially available for harvest per hectare, and relatively high costs of harvesting and transporting compared with woody biomass. Regrowth is the least expensive at ~$56 t −1 due to low establishment and maintenance costs. We conclude that the case study region has the potential to produce sufficient biomass to support the hypothetical industry scale-up and that a mixed feedstock base maximises the sustainability of biomass supply. We discuss a range of sustainability issues associated with biomass production.

The airline industry has a strong interest in developing sustainable aviation fuels, in order to reduce their exposure to increasing oil prices and cost liability for greenhouse gas emissions. The feasibility and cost of producing sustainable biomass-based jet fuels at a sufficient scale to materially address these issues is an enormous challenge. This paper builds directly on the biophysical study by H.T. Murphy, D.A. O'Connell, R.J. Raison, A.C. Warden, T.H. Booth, A. Herr, A.L. Braid, D.F. Crawford, J.A. Hayward, T. Javonovic, J.G. McIvor, M.H. O'Connor, M.L. Poole, D. Prestwidge, N. Raisbeck-Brown & L. Rye, In review, which examined a 25 year scale-up strategy to produce 5% of projected jet fuel demand in Australia in 2020 (470 mL) in the Fitzroy region of Queensland, Australia. The strategy was based on the use of a mixed ligno-cellulosic biomass feedstock and assumed, for the sake of exploring and quantifying the scenario, a simplified two-step conversion process – conversion of biomass to crude bio-oil within the region, and upgrade to jet fuel at a central Brisbane facility. This paper provides details on the costs of production in this scenario, focusing on two different strategies for biomass utilization, and two types of novel small–medium scale conversion technologies. The cost analyses have taken into account technology learning curves, different economies of scale and key cost sensitivities. The cost of biomass-based jet fuels is estimated to be between 0.70 and 1.90 $ L−1 when the efficiency of conversion of biomass to biocrude and subsequently to aviation fuel is varied by ±10% of published values, with an average value of 1.10 $ L−1. This is within the range of the projected 2035 conventional jet fuel price of 1.50 $ L−1. Therefore, biomass-based jet fuel has the potential to contribute to supply of Australia's jet fuel needs in the future.

SummaryThis 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 syste...

The importance of ecological management for reducing the vulnerability of biodiversity to climate change is increasingly recognized, yet frameworks to facilitate a structured approach to climate adaptation management are lacking. We developed a conceptual framework that can guide identification of climate change impacts and adaptive management options in a given region or biome. The framework focuses on potential points of early climate change impact, and organizes these along two main axes. First, it recognizes that climate change can act at a range of ecological scales. Secondly, it emphasizes that outcomes are dependent on two potentially interacting and countervailing forces: (1) changes to environmental parameters and ecological processes brought about by climate change, and (2) responses of component systems as determined by attributes of resistance and resilience. Through this structure, the framework draws together a broad range of ecological concepts, with a novel emphasis on attributes of resistance and resilience that can temper the response of species, ecosystems and landscapes to climate change. We applied the framework to the world’s largest remaining Mediterranean-climate woodland, the ‘Great Western Woodlands’ of south-western Australia. In this relatively intact region, maintaining inherent resistance and resilience by preventing anthropogenic degradation is of highest priority and lowest risk. Limited, higher risk options such as fire management, protection of refugia and translocation of adaptive genes may be justifiable under more extreme change, hence our capacity to predict the extent of change strongly impinges on such management decisions. These conclusions may contrast with similar analyses in degraded landscapes, where natural integrity is already compromised, and existing investment in restoration may facilitate experimentation with higher risk options.

There is an increasingly well-founded understanding of the chief drivers and constraints to widespread adoption by Australian landholders to practices to manage dryland salinity. However, each specific situation depends on a range of biophysical, social and economic factors. Such is the case in this study that examines farmers' salinity management in the Wallatin-O'Brien catchments in the low-medium rainfall zone of the Western Australian wheatbelt. The study involved interviews with landholders and economic modelling of representative farms and salinity management options to gain an understanding of the farmers' adoption behaviour regarding salinity management. Most landholders interviewed saw dryland salinity as a second order farm management issue, due first to the relatively slow rate of expansion of saline land within the catchments and second, because the changes in land use required to prevent further loss of land to salinity were viewed as being uneconomic. The exception to this was the minority (

In the preceding papers, the authors evaluate the usefulness of the proposition that mimicking characteristics of natural ecosystems, particularly patterns of resource capture and distribution, can lead to improved sustainability of agricultural systems. They approach this question from a diverse array of disciplines over a broad range of geographical settings and ecosystems and produce an equally broad range of views and conclusions. The aim of this paper is to draw out the major themes that have emerged concerning the usefulness of the mimic concept in generating radical solutions to the problem of agriculture. First, a brief summary of their scope and conclusions.

In this article we assess the potential for developing mimics in situations where detailed data on the ecophysiology and ecosystem function of the native ecosystem are not available. We examine two ecosystems in south western Australia, and draw together available information on these. We discuss woodlands dominated by Eucalyptus salmonophloia, which formerly covered much of the valley bottom land in the Western Australian wheatbelt, and kwongan or heath which occurs on sandplain soils at the top of the landscape. From both of these we derive possible mimics which utilise aspects of the native vegetation which we hypothesise contributed to ecosystem function and resilience, but which still allow the production of a harvestable agricultural product. We conclude that situations for which we have adequate ecological knowledge from which to develop sound mimics are likely to be rare. We hence have to be prepared to make best-bet estimates and use these to develop experimental mimic systems.

We provide a quantitative assessment of the prospects for current and future biomass feedstocks for bioenergy in Australia, and associated estimates of the greenhouse gas (GHG) mitigation resulting from their use for production of biofuels or bioelectricity. National statistics were used to estimate current annual production from agricultural and forest production systems. Crop residues were estimated from grain production and harvest index. Wood production statistics and spatial modelling of forest growth were used to estimate quantities of pulpwood, in-forest residues, and wood processing residues. Possible new production systems for oil from algae and the oil-seed tree Pongamia pinnata, and of lignocellulosic biomass production from short-rotation coppiced eucalypt crops were also examined. The following constraints were applied to biomass production and use: avoiding clearing of native vegetation; minimizing impacts on domestic food security; retaining a portion of agricultural and forest residues to protect soil; and minimizing the impact on local processing industries by diverting only the export fraction of grains or pulpwood to bioenergy. We estimated that it would be physically possible to produce 9.6 GL yr−1 of first generation ethanol from current production systems, replacing 6.5 GL yr−1 of gasoline or 34% of current gasoline usage. Current production systems for waste oil, tallow and canola seed could produce 0.9 GL yr−1 of biodiesel, or 4% of current diesel usage. Cellulosic biomass from current agricultural and forestry production systems (including biomass from hardwood plantations maturing by 2030) could produce 9.5 GL yr−1 of ethanol, replacing 6.4 GL yr−1 of gasoline, or ca. 34% of current consumption. The same lignocellulosic sources could instead provide 35 TWh yr−1, or ca. 15% of current electricity production. New production systems using algae and P. pinnata could produce ca. 3.96 and 0.9 GL biodiesel yr−1, respectively. In combination, they could replace 4.2 GL yr−1 of fossil diesel, or 23% of current usage. Short-rotation coppiced eucalypt crops could provide 4.3 GL yr−1 of ethanol (2.9 GL yr−1 replacement, or 15% of current gasoline use) or 20.2 TWh yr−1 of electricity (9% of current generation). In total, first and second generation fuels from current and new production systems could mitigate 26 Mt CO2-e, which is 38% of road transport emissions and 5% of the national emissions. Second generation fuels from current and new production systems could mitigate 13 Mt CO2-e, which is 19% of road transport emissions and 2.4% of the national emissions lignocellulose from current and new production systems could mitigate 48 Mt CO2-e, which is 28% of electricity emissions and 9% of the national emissions. There are challenging sustainability issues to consider in the production of large amounts of feedstock for bioenergy in Australia. Bioenergy production can have either positive or negative impacts. Although only the export fraction of grains and sugar was used to estimate first generation biofuels so that domestic food security was not affected, it would have an impact on food supply elsewhere. Environmental impacts on soil, water and biodiversity can be significant because of the large land base involved, and the likely use of intensive harvest regimes. These require careful management. Social impacts could be significant if there were to be large-scale change in land use or management. In addition, although the economic considerations of feedstock production were not covered in this article, they will be the ultimate drivers of industry development. They are uncertain and are highly dependent on government policies (e.g. the price on carbon, GHG mitigation and renewable energy targets, mandates for renewable fuels), the price of fossil oil, and the scale of the industry. published

"Natural resource scientists and managers increasingly recognize traditional ecological knowledge (TEK) for its potential contribution to contemporary natural resource management (NRM) and, through this, to more resilient social-ecological systems. In practice, however, inadequate cross-cultural means to organize and communicate TEK can limit its effective inclusion in management decisions. Indigenous seasonal knowledge involving temporal knowledge of biota, landscapes, weather, seasonal cycles, and their links with culture and land uses is one type of TEK relevant to this issue. We reviewed the literature on Australian Aboriginal seasonal knowledge to characterize contemporary and potential applications to NRM. This knowledge was often documented through cross-cultural collaboration in the form of ecological calendars. Our analysis revealed a variety of basic and applied environmental information in Aboriginal seasonal descriptions and calendars that can contribute directly to NRM. Documented applications have been limited to date, but include fire management, inclusion as general material in NRM plans, and interpretative information about environments. Emerging applications include water management and climate change monitoring. Importantly, seasonal knowledge can also contribute indirectly to NRM outcomes by providing an organizing framework for the recovery, retention, and crosscultural communication of TEK and linking to its broader cultural and cosmological contexts. We conclude that by facilitating the combination of experiential with experimental knowledge and fostering complementarity of different knowledge systems, Aboriginal seasonal knowledge can increasingly contribute to more resilient social-ecological outcomes in NRM. Nevertheless, the seasonal framework should augment, rather than override, other approaches to cross-cultural NRM such as those with spatial and/or social-ecological emphasis."

Many estimates have been made of the future likely extent of salinity at regional and national scales in Australia; however, there are few detailed studies of changes in temporal and spatial patterns at catchment scale. This study was conducted in the Wallatin and O’Brien catchments in the low–medium rainfall zone of the central wheatbelt of Western Australia, where we examined the spatial trends in saline land over the last 18 years and related these to the likely rate and extent of future salinisation. The analysis showed that: (1) salinity has continued to expand post-1999 in landscape positions where there has been watertable rise and also in areas now at equilibrium even though rainfall has been below average; (2) increases in the area of salinity are still dominated by increases in the valley floor but there is now the emergence of many small, isolated outbreaks on the adjacent slopes; (3) widely available satellite-derived salinity maps (LandMonitor) derived in 1998 provide a reliable base-line for saline mapping but now underestimate the area of salt-affected land by 60%; (4) the trend in watertable levels and time since clearing and interactions with proximity to uncleared native vegetation provide reliable predictors of salinity risk; (5) episodic rainfall in areas of shallow watertables is proposed as a significant cause of the expansion in observed salinisation, even though some of this may be transient. These results are discussed in terms of management options for farmers and the likely long-term outlook for expansion of salinity in the catchment.

Scenario planning was used to identify issues and drivers of change that are relevant to community efforts to improve regional prospects in the Western Australian Wheatbelt. The region, some 20 million hectares in area, is under pressure to respond to a variety of environmental (salinity, erosion, acidification, biodiversity decline), economic (declining agricultural terms of trade), and social forces (rural decline, isolation). Regional strategic plans have been increasingly seen as the means of achieving sustainability in the face of these challenges, but until recently typically had single-activity outlook and timeframes of up to a decade into the future. Systematic futures-based research has been used in various regions to avoid reliance on business-as-usual as the default strategy, and to identify opportunities and challenges not presently apparent. The Avon River Basin, the central region of the Wheatbelt, was selected as the geographic focus of the project, and the time horizon was set at 2050. The project was developed by a group of 50 stakeholders from the basin, with expertise and strategic interests across a wide range of economic, social, and environmental themes. Through a series of workshops the stakeholders identified critical issues and their attendant drivers, then documented relevant past trends. Four regional scenarios, Saline Growth, Grain and Drain, Landcare Bounty, and Harmony with Prosperity, were developed based on positive and negative combinations of 2 clusters of uncertain and important drivers: environmental change and access to new markets. Common opportunities, threats, and critical success factors for the Avon River Basin region out to 2050 were also identified. We also found that the stakeholders have a tendency to strive for positive outcomes despite negative initial conditions. This resulted in 4 scenarios that were superficially similar due to the regional scale of analysis and the continuation of agricultural industries as significant shapers of economy, society, and environment. However, each scenario represents profoundly different outcomes for the residents and communities of the Avon River Basin in 2050. The triple-bottom line outcomes for the Avon River Basin in 2050 were estimated to be in the range 4.9–9.7 Mt of wheat (currently 4.0), 46 000–66 000 people (currently 43 000), and 10–30% of farmland salinised (currently 6). The application of these results to other regions in Australia is discussed.