Abstract
Fire management across Australia's fire-prone 1.2 M km2 northern savannas region has been transformed over the past decade supported by the inception of Australia's national regulated emissions reduction market in 2012. Today, incentivised fire management is undertaken over a quarter of that entire region, providing a range of socio-cultural, environmental, and economic benefits, including for remote Indigenous (Aboriginal and Torres Strait Islander) communities and enterprises. Building on those advances, here we explore the emissions abatement potential for expanding incentivised fire management opportunities to include a contiguous fire-prone region, extending to monsoonal but annually lower (<600 mm) and more variable rainfall conditions, supporting predominantly shrubby spinifex (Triodia) hummock grasslands characteristic of much of Australia's deserts and semi-arid rangelands. Adapting a standard methodological approach applied previously for assessing savanna emissions parameters, we first describe fire regime and associated climatic attributes for a proposed ∼850,000 km2 lower rainfall (600–350 mm MAR) focal region. Second, based on regional field assessments of seasonal fuel accumulation, combustion, burnt area patchiness, and accountable methane and nitrous oxide Emission Factor parameters, we find that significant emissions abatement is feasible for regional hummock grasslands. This applies specifically for more frequently burnt sites under higher rainfall conditions if substantial early dry season prescribed fire management is undertaken resulting in marked reduction in late dry season wildfires. The proposed Northern Arid Zone (NAZ) focal envelope is substantially under Indigenous land ownership and management, and in addition to reducing emissions impacts associated with recurrent extensive wildfires, development of commercial landscape-scale fire management opportunities would significantly support social, cultural and biodiversity management aspirations as promoted by Indigenous landowners. Combined with existing regulated savanna fire management regions, inclusion of the NAZ under existing legislated abatement methodologies would effectively provide incentivised fire management covering a quarter of Australia's landmass. This could complement an allied (non-carbon) accredited method valuing combined social, cultural and biodiversity outcomes from enhanced fire management of hummock grasslands. Although the management approach has potential application to other international fire-prone savanna grasslands, caution is required to ensure that such practice does not result in irreversible woody encroachment and undesirable habitat change.
| Original language | English |
|---|---|
| Article number | 118384 |
| Pages (from-to) | 1-18 |
| Number of pages | 18 |
| Journal | Journal of Environmental Management |
| Volume | 344 |
| DOIs | |
| Publication status | Published - 15 Oct 2023 |
Bibliographical note
Funding Information:The project received funding from the Indigenous Land and Sea Corporation, The Nature Conservancy , Northern Territory Government (Department of Environment, Parks and Water Security), Central Land Council, Kimberley Land Council, and the 10 Deserts Project.
Funding Information:
Over the past two decades significant efforts have been undertaken to develop market-based approaches for incentivizing more environmentally, culturally, and economically sustainable fire management outcomes across Australia's sparsely settled, annually fire-prone northern savannas region. This has involved learning from and applying Indigenous (Aboriginal and Torres Strait Islander) relatively fine scale (multi-hectare) burning practices undertaken progressively and systematically over the seasonal cycle. Coupled with development of ‘savanna burning’ greenhouse gas (GHG) emissions and developing carbon sequestration accounting methods and a national regulated carbon offsets market, landscape-scale fire management activities financially reward reducing the extent of late dry season wildfires and associated GHG emissions (Russell-Smith et al., 2013; CoA, 2015, 2018). Currently there are almost 80 savanna burning projects registered with the Australian Government under the Emission Reduction Fund, covering a quarter of the 1.2 M km2 northern savannas region eligible under existing Commonwealth methodologies, and having delivered over 11.2 M Australian Carbon Credit Units (where 1 ACCU = 1 t. CO2-e) of which 75% have been delivered by Indigenously owned and managed projects (CoA 2022). Savanna burning projects have transformed more sustainable fire management practice in northern Australia, along with delivering significant environmental, ecosystem services and cultural co-benefits (Ansell et al., 2020; Edwards et al., 2021; Sangha et al., 2021).This assessment essentially extends and adapts ‘savanna burning’ methods previously developed for Australian savanna systems under the same monsoonal but higher rainfall (>600 mm MRR) conditions (Russell-Smith et al., 2009; Murphy et al., 2015; Lynch et al., 2018). Based on foundational research undertaken for existing methods to date, the Australian Government has implemented formal savanna burning GHG emissions and preliminary sequestration accounting procedures to service national regulatory market-based agricultural offset arrangements through the national Emissions Reduction Fund (https://www.cleanenergyregulator.gov.au/ERF), in accord with Australia's National Greenhouse Gas Inventory accounting commitments.However, where spinifex hummocks carried fire in our treatments, mean fine fuel and shrub consumption was only slightly less in the EDS than under LDS conditions, supporting drone-based observations that internal fire scar patchiness was essentially equivalent in both periods. Consumption of both fine fuel and especially shrub fuel components was found to be proportionately greater than has been observed for other LRZ hummock grass VFTs, whereas combustion of negligible CWD and sparsely sampled heavy woody fuel loads was found to be idiosyncratic compared with other LRZ observations (Yates et al., 2015; Lynch et al., 2018).In the NAZ, our N2O EFs ranged from 0.18 to 0.70%N which is again in line with previous measurements in hummock grass open woodlands and measurements of isolated spinifex grasses. In the HRZ, Meyer et al. (2012) found N2O EFs ranging from 0.47 to 1.04%N for OWTu, 0.09–1.19%N for hummock grass open woodland, and 0.36–0.93%N for pure spinifex. Hurst et al. (1994) found average N2O EFs of 0.76 ± 0.38%N for hummock grass open woodland fires measured in July 1990. Particularly for spinifex, Meyer et al. (2012) reported a distinct seasonal difference increasing from 0.42%N in July to 0.72%N in September. We found a similar seasonal dependence in the spinifex in the Tanami region, which supports the abatement potential of prescribed EDS burning.The project received funding from the Indigenous Land and Sea Corporation, The Nature Conservancy, Northern Territory Government (Department of Environment, Parks and Water Security), Central Land Council, Kimberley Land Council, and the 10 Deserts Project.All authors reports financial support was provided by Indigenous Land And Sea Corporation. All authors reports financial support was provided by The Nature Conservancy. All authors reports financial support was provided by Northern Territory Government Department of Environment, Parks and Water Security. All authors reports financial support was provided by Central Land Council. All authors reports financial support was provided by Kimberley Land Council. All authors reports financial support was provided by 10 Deserts Project.
Publisher Copyright:
© 2023 The Authors
