Planting the smart seed

Professor Kingsley Dixon is a conservation biologist and restoration ecologist at Curtin University in Perth, Western Australia, whose research has transformed the scientific basis of ecological restoration in Australia and around the world. Professor Dixon’s expertise spans many fields, including conservation practices for mine site restoration and the re-establishment of bushland plants, and saving threatened and ‘near-extinct’ species as part of rebuilding damaged landscapes.

Many of these threads are drawn together at the Australian Research Council (ARC) Industrial Transformation Training Centre for Mine Site Restoration (CMSR), led by Professor Dixon, which is the largest collective centre in Australia devoted to mining restoration. Awarded by the ARC in 2015, the Training Centre is focused on delivering cost-effective solutions to mine restoration at scale.

CMSR has eight active industry partners, comprising a number of major mining companies operating in Australia including BHP Biliton, Karara Mining and Mineral Resources Ltd. Professor Dixon says that interest from the mining industry has powered the research behind site rehabilitation for many years.

“It was actually a mining company that first came to me, back in 1985, for help in rehabilitating a site which had a population of the rare plant the Hidden Beard Heath (Leucopogon obtectus)—a plant that has a notoriously cryptic ecology and a deep seed dormancy which still eludes us to this day,” said Professor Dixon.

Despite this interest, and the fact that mining accounts for approximately 40 per cent of Australia’s export wealth, the difficulties in effective mine site restoration are still a major impediment to compliance with regulatory, business, environmental and social requirements.

“Australia has 50,000 abandoned mines, affecting over 200,000km² and at least 15,000 plant and animal species are impacted. None of these mines have had a successful mine closure that can reinstate the natural ecosystem removed as part of the mining operation. The costs have been described as ‘chilling’. But if mining companies plan for closure from the moment that they peg the resource for the life-of-mine, through activities like storing topsoil, we have shown that the costs can be 4 to 10 times lower.”

Rejuvenating mine sites involves collecting and storing large quantities of seed from local species for replanting on the site, a task that has a number of logistical, ecological and ethical challenges. In response to the challenge of increasing the success rate of planting seeds, researchers at CMSR are developing ‘smart seed’ coatings that are inoculated with clever growth stimulants and biological agents to aid seed germination and boost early seedling growth, even in hostile conditions.

One of these chemicals is only known to science as a result of Professor Dixon’s discovery, in 2004, of the exact molecule in smoke that stimulates germination of seeds following a bushfire. The discovery, which made international headlines, was the result of a ‘typical Australian larrikin approach’ which led Professor Dixon’s team to ‘doggedly’ test each of the 4000+ chemicals in smoke in order to identify the mysterious molecule.

The Australians beat several well-funded international teams to the discovery. “Everyone told us to give up; researchers who were on the trail of the smoke chemical from the prestigious Max Planck institute had given up on the search and advised us to do the same and save our money. We persisted for 11 years and finally we located the mystery molecule,” says Professor Dixon, reminiscing about how the research team closed in on the discovery.

This chemical has now been extensively studied, its activity characterised, and it has been named ‘Karrikinolide’, in honour of the Indigenous Noongar Peoples’ word for smoke, which is ‘Karrik’.

As well as use in coatings for boosting the germination of native seeds, Karrikinolide has potential for controlling weeds in crops that costs Australian agriculture more than $6 billion in chemicals each year. Karrikinolide forces dormant weeds to sprout early, so removing them from soil that would otherwise be weed-contaminated for many years.

Professor Dixon says that Indigenous owners of the land where mining takes place are playing a significant role in its restoration. An Indigenous-owned and operated native seed farm has been established with help from CMSR to produce a reliable supply of important plant species needed in rehabilitation programs. Run by the Midwest Employment and Economic Development Aboriginal Corporation, the farm employs local Indigenous people in all phases from the planting, management, harvesting and processing of seed ready for sowing into mine sites.

Professor Dixon hopes that the seed farm will become a successful business model which could be adopted by other Indigenous communities around Australia. This is not the only example of local Indigenous owners becoming deeply involved in mine restoration.

“The Argyle diamond mine closes in two years, and a local organisation, the Gelganyem Trust, manages the funds and assets on behalf of the Traditional Owners.  It has been uplifting to work with the traditional owners leading this organisation, and who have a strong vision of how that land will be returned.”

Professor Dixon says that their position is encapsulated in what they have said to mine owners: “We lent to you our country on the condition it comes back to us healthy, and our people are better off as a result of the loan.”

The Centre for Mine Site Restoration has a large number of PhD and post-doctoral students working on related projects that are spun out of the core mission of the Centre, some with their own stream of funding and industry partnerships. Ms Sophie Cross, who was featured in the ARC’s Making a Difference: Outcomes of ARC supported research 2018-19 edition, won a scholarship that supports her work on the long term effect on animals at mine sites. Other researchers at CMSR are pursuing techniques that allow detailed analysis of DNA from soil samples, as an indicator of soil health, and can also detect the presence of endangered species such as the Pilbara leaf-nosed bat.

“The exciting thing about this research is taking things like the smoke discovery, our threatened species conservation and the ways we repair damaged landscapes, and bring it together as packages not only for communities but out into a whole range of different industries,” Professor Dixon explains.

The next stage is sharing the learnings from these activities internationally, which is now occurring through the Society for Ecological Restoration Australia (SERA) a partner organisation in the CMSR, for which Professor Dixon was the foundation Chair. SERA’s publication of National Standards for the Practice of Ecological Restoration, has given rise to the International version of the Standards  which places ecological restoration into a global context, including its role in conserving biodiversity and improving human wellbeing.

Professor Dixon says there is increasing interest internationally in the work that is being undertaken at CMSR, and that Australia is leading the way in this growing field.

“China is intolerant of mining companies not cleaning up... they are investing one trillion dollars in restoring all damaged landscapes.” And as tragic events such as the collapse of two tailings dams in Brazil, in 2015 and 2019, make evidently clear, the need for forward-thinking about the human and environmental consequences of mining activity is more important now than ever.

Images (from top):

Professor Dixon leading a group of gifted indigenous students on a tour of mining restoration. Credit: CMSR.

Part of the CMSR team testing new hand-held monitors for determining plant health in restoration. Credit: CMSR.

One of Australia’s first indigenous owner operated native seed farm to generate seed of species missing from mines due to lack of seed. Credit: CMSR.