Potential of woody biomass production for motivating widespread natural resource management under climate change.

摘要

In this study we assessed the potential of woody biomass (short-rotation Mallee Eucalypts) for renewable energy generation as an economically viable way of motivating widespread natural resource management under climate change in the 11.9 million ha Lower Murray agricultural region in southern Australia. The spatial distribution of productivity of agricultural crops and pasture, and biomass was modelled. Average annual economic returns were calculated under historical mean (baseline) climate and three climate change scenarios. Economically viable areas of biomass production were identified where the profitability of biomass is greater than the profitability of agriculture under each scenario for three factory gate biomass prices. The benefits of biomass production for dryland salinisation, wind erosion, and carbon emissions reduction through biomass-based renewable energy production were also modelled. Depending on climate scenario, at the median price assessed ($40/tonne) biomass production can generate $51.4-$88 M in annual net economic returns, address 41,226-165,577 ha at high risk of dryland salinisation and 228,000-1.4 million ha at high risk of wind erosion, and mitigate 10.4-12 million tonnes of carbon (CO₂-e) emissions annually. Economically viable areas for biomass production expanded under climatic warming and drying especially in more marginal agricultural land. Under the baseline, the area at high risk of dryland salinisation was more than double that at high risk of wind erosion. However, under climatic warming and drying the relative importance of these two natural resource management objectives switched with the area at high risk of wind erosion becoming much larger. As biomass production can achieve multiple natural resource management objectives, it may provide a land use policy option that is adaptable to changing priorities and economically resilient given climatic uncertainties. For such a significant and enduring land use change policy it is prudent to assess both the economic and environmental potential under climate change.