Biodiverse Planting for Carbon and Biodiversity on Indigenous Land

By Anna. R. Renwick, NERP Environmental Decisions Hub, University of Queensland, Brisbane

Climate change has prompted the development of methods to reduce greenhouse gases in the atmosphere, and many countries have established emissions trading schemes that offer incentives to offset carbon emissions. In addition to carbon storage, these schemes have the potential to deliver other environmental benefits, such as biodiversity conservation and the provision of other ecosystem services. One carbon trading scheme is the Carbon Farming Initiative (CFI), established by the Australian government to provide opportunities for land managers and local communities to reduce or sequester carbon emissions by altering land management practices. Tree planting is one approved method to sequester carbon and, if mixed native trees are planted, has the potential to provide additional ecosystem services.

What makes the CFI legislation unique is that it contains provisions for benefits to biodiversity and indigenous communities. Many indigenous leaders in Australia have shown interest in carbon offset projects, and the associated co-benefits and opportunities they provide (such as increased access to education, training and decision making powers). However, it is unknown how to determine the optimum locations for tree planting to ensure the most ‘bang for their buck’. We therefore conducted a spatial analysis of the carbon and biodiversity potential of planting biodiverse native vegetation on indigenous land across Australia.

Using the conservation planning tool Marxan and an economic scenario reflecting the Australian government’s 2011-2013 carbon trading price of AU$23/tonne, we calculated the cost-effectiveness of areas across Australia for sequestering carbon and restoring each vegetation type up to 30% of its pre-1750 extent. We then determined the relative priority of the areas for meeting the combined carbon and biodiversity restoration target cost-effectively. Finally, we overlaid the map of indigenous land tenure (composed using data sourced from the official agencies responsible for the registration of various indigenous land tenures) with maps of carbon sequestration, biodiversity features, the relative priority areas to determine the proportion of carbon and biodiversity goals that can be met on indigenous land, and the proportion of priority areas on indigenous land.

Approximately 92 million hectares of land in Australia has been cleared and have the potential to be replanted with native vegetation, sequestering around 710 million tonnes of CO2/year over the next 40 years.

The amount of this area that is available depends on the profitability for environmental planting, which is based on the carbon price and other economic, social, and practical constraints in the area. Using Australia’s 2011-2013 carbon trading price of AU$23/tonne, 31 million hectares of the area are profitable for carbon farming, which would sequester 294 million tonnes of CO2. Almost a third of this area, 9.7 million hectares, is on indigenous land and could sequester 83 million tonnes of CO2 (28% of the total). If, however, the price of carbon drops to AU$5/tonne, close to the 2013 international markets, the profitable area for carbon farming is reduced severely to only 5 million hectares and the potential for indigenous communities to get involved would be limited.

Almost 19% of the combined high and very high priority areas for cost-effectively meeting biodiversity goals are on indigenous lands, primarily in southeast Queensland, eastern New South Wales, south-west Victoria, south-east South Australia and south-west Western Australia. There are few carbon and biodiversity benefits from planting on indigenous land in northern Australia, reflecting the low density of forests and historical clearing in this area, although alternative carbon offset schemes in this area may be more appropriate (savanna burning, for example). Given that indigenous land covers 19% of the total biodiversity plantable area, this result indicates that indigenous lands are approximately as important as the rest of Australia for achieving this combined goal cost-effectively.

This top-down approach provides one potential way for indigenous communities to get involved in carbon projects. The next stage is to test these model results in partnership with local indigenous communities who may require additional information, special training and community engagement skills. Despite the positive potential for the CFI to contribute to biodiversity and benefit indigenous communities and broader society, recent changes in the government of Australia highlight the instability of the policy and political environment surrounding the CFI and present new risks and uncertainties to carbon farming efforts, including those adopted by indigenous communities.

Read the full study: Biodiverse planting for carbon and biodiversity on Indigenous land