The Australian microbial landscape: Empowering mine rehabilitation
/
Mining is a major industry in Australia, contributing significantly to the economy and providing approximately 220,000¹ jobs, especially in regional areas. However, the environmental challenges associated with mining such as land degradation, biodiversity loss, and water pollution can be dramatic and long-lasting. These issues don’t end when mines close, as rehabilitating the land back to a safe and usable state requires time, planning and resources. Climate change further complicates this process, making many traditional rehabilitation methods less effective. For Indigenous landowners, the stakes are even higher, as inadequate rehabilitation can damage culturally and economically significant lands, disrupt their connection to the environment, and amplify the long-term consequences of mining.²
Restoring land to an acceptable ecological state is an enormous challenge. It involves re-introducing native vegetation to landscapes that have been significantly altered. The topsoil is frequently degraded and compacted, which affects the types of plants that can grow in these areas. Historically, this has led to high rates of failure, forcing mining companies or regional communities to invest in replanting efforts, sometimes repeatedly. In other cases, large areas of Australian land are left damaged and of little value to local communities.³
In collaboration with Cooperative Research Centre for Transformations in Mining Economies (CRC-TiME), AGRF is partnering with mining companies, government organisations, researchers and Indigenous communities to provide data that will support innovative strategies for climate resilient mine rehabilitation. The long-term goal is to return mined land to its original ecological state or a condition that meets community and environmental needs. Additionally, the project aims to empower Indigenous communities to lead and actively participate in mine closure and rehabilitation as custodians of the land. The aim is to integrate Traditional Ecological Knowledge (TEK) with modern technologies empowering Indigenous people with the skills to monitor land health and guide rehabilitation efforts. By fostering partnerships between Indigenous groups, mining companies, and researchers, these efforts not only strengthen on-site land stewardship but also provide valuable leadership and employment opportunities for Indigenous communities.⁴
Several projects under this collaboration are testing strategies to regenerate post-mine sites in ways that are climate resilient. One promising approach involves adjusting seed sourcing strategies to account for imminent climate change. The current “best practice” is to source seeds locally, to work with the local stock and environmental adaptations inherent in its genetics and epigenetics. This study explores whether seeds of the same species collected from hotter, drier environments could boost successful restoration and resilience in the resulting landscape.⁵ While the genetic and epigenetic composition of the seed is key, their growth also depends on the microbial components of the degraded surface soil available. It is this below-ground biodiversity that provides nutrient cycling and plant-microbe interactions, critical for the success of developing flora.
How genomics can enhance rehabilitation efforts
To test the effectiveness of these seed sourcing strategies, five experimental revegetation planting sites have been established across Australia. These sites are being monitored for short- and long-term outcomes, evaluating different seed sourcing options to improve post-mine rehabilitation.
AGRF’s role in this initiative is developing technology that uses the knowledge of soil bacterial communities to uncover the “land memory “the ability to read the soil’s history and understand its original vegetation and monitor its trajectory of change as the site rehabilitates. Using our Next-Generation Sequencing services, we are creating detailed genomic profiles of the soil microbiota, providing insights into current soil status and tracing its changes over time. By comparing this microbial community structure data of the rehabilitating soils with other Australia-wide soil and vegetation datasets, we aim to form a complete picture of the landscape’s past and present conditions.
The ultimate goal is to develop a technological solution that applies DNA sequencing to guide land rehabilitation efforts, helping mining companies, regulators, and conservationists select the most suitable seed species based on the initial genomic profile of the soil. As the site recovers, the changing microbial profile will indicate the system’s health and suggest necessary interventions to steer it on a desired trajectory. By leveraging AGRF’s DNA sequencing services and combining microbial and environmental data, this approach aims to enhance the success of long-term site restoration. It ensures that land management practices are informed by the soil’s land memory, helping to align management practices with the soil’s historical and current metabolic potential for more effective rehabilitation.
AGRF has developed a computational tool that integrates data from the Australian Microbiome Initiative and government sourced databases on land usage and land vegetation type. This will provide a valuable resource for decision-makers exploring the intersection of soil health and successful land rehabilitation. This online tool allows tested soil samples to be embedded and compared against a national dataset of thousands of other samples, providing a broader context for understanding soil conditions at the site in context with soils across Australia.
Through these efforts, AGRF aims to play a critical role in transforming how mine sites are rehabilitated in Australia, ensuring restoration efforts are resilient and responsive to the challenges posed by climate change.
References:
¹ Australian Bureau of Statistics, May 2024, Australian Industry, Available at https://www.abs.gov.au/statistics/industry/industry-overview/australian-industry/ latest-release, Accessed 18 November 2024.
² Centre for Social Responsibility in Mining (2020), Indigenous groups, land rehabilitation and mine closure: exploring the Australian terrain, Available at: https://www.csrm.uq.edu.au/publications/indigenous-groups-land-rehabilitation-and-mine-closure-exploring-the-australian-terrain, Accessed 17 October 2024.
³ CRCTiME (2024), Project 4.6_Evidence for effective climate-adapted seed sourcing strategies. Available at https://crctime.com.au/research/projects/ project-4-6/, Accessed 17 October 2024.
⁴ CRCTiME (2024) Project 4.6 _ Evidence for effective climate-adapted seed sourcing strategies for revegetation success and transition to mine closure in a changing climate, [PowerPoint presentation] Accessed 21 October 2024.
⁵ The Westmead Institute for Medical Research, INOVATe, Available at https://www.westmead
