We are taking a look back at stories from Cosmos Magazine in print. In June 2024, David Hancock wrote about a partnership between a young Brazilian scientist, a veteran horticulturalist and First Nations people of the West Kimberley, in Western Australia, that promises to improve biodiversity and heal Country damaged by wildfires and land clearing.
When she first arrived in the West Australian Kimberley six years ago, Sara Cavalcanti Marques felt a strong affinity with the region. This vast area of dramatic and relatively undisturbed landscapes, cut by pristine rivers, forms a haven for rare plants and animals. The lush, warm ecosystem with a strong tradition of Indigenous land stewardship reminded her of her birthplace of Belém, at the mouth of the Amazon in northern Brazil.
Initially based in Perth at Murdoch University, the young scientist – who holds a bachelor’s degree with honours in terrestrial ecology from São Paulo State University – was so entranced by the West Kimberley that she sought opportunities to work with First Nations people in native food production and land stewardship practices.
She contacted First Nations research institutes in Broome including North Regional (NR) TAFE, which works with Traditional Owners and trains First Nations students in conventional horticultural techniques, such as large-scale irrigation. Almost by chance, Cavalcanti Marques came across Kim Courtenay, one of northern Australia’s most experienced horticulturalists, who has spent decades working with First Nations people of the Kimberley. Courtenay has been on the payroll of NR TAFE for 29 years and has long-established links with Traditional Owners and remote communities.
Aside from training, NR TAFE staff help communities establish their own gardens and native food plantations, assist pastoralists with restoring degraded land and provide skills to inmates at rehabilitation institutions such as the West Kimberley Regional Prison. Importantly for Cavalcanti Marques, one of the first initiatives Courtenay launched for NR TAFE was an on-Country learning centre, called Balu Buru, “place of trees” in the local Yawuru language: a 20-hectare site outside Broome dedicated to training, cultivating native species and developing sustainable land-management practices.
Courtenay is particularly interested in the concept of “savanna enrichment”, where certain native flora species, usually trees, are planted within existing vegetation. Coupled with regular early-season burning, the practice results in productive woodlands where natural biodiversity is preserved and enhanced.
Much of northern Australia’s vegetation is dominated by various fire-tolerant acacias. In many places fires come through, the acacias burn and then regenerate more thickly, creating even hotter fires next time there’s a burn. During intense fires, a lot of long-lived native trees are destroyed and the landscape effectively changes from tropical woodland to scrub. Where once stood large eucalypts (such as bloodwoods, stringybarks and woollybutts), boabs, bauhinias, kurrajongs and others, often there are burned, twisted skeletons.
“This means you lose biodiversity,” Courtenay says. “And you lose the bush foods so important to Aboriginal people. Those are plants that they used to go and collect and obtain so much goodness from. Savanna enrichment is basically reversing that process [of losing bush food plants]. We are re-establishing the valuable native plants and using various methods to suppress or replace the acacia thickets.”
It is a land-management technique used by Courtenay for decades and First Nations people for generations, yet they have only been able to provide anecdotal evidence of its success. Savanna enrichment uses traditional practices such as cool, patchy fires and caring for bush produce plants that have always been part of First Nations culture. For Western science, savanna enrichment is yet to be proved.
Enter Sara Cavalcanti Marques.
The Brazilian is undertaking a PhD project at Murdoch University called “Assessing the Social and Ecological Benefits of Bush Tucker Inclusion and Land Stewardship Practices”. Its main aim is to scientifically prove the ecological process and benefits of savanna enrichment. It’s also expected to open up extensive economic opportunities for First Nations businesses and communities.
“TAFE and Kim [Courtenay] have been doing this for several years,” Cavalcanti Marques says. “We know that it works on the ground as a model for bush produce cultivation, but the idea is trying to quantify those benefits in order to get more support behind it, so this activity can be rolled out on a bigger scale.
“So far, it has happened in very specific, punctual cases from the TAFE and across a couple of different communities. The idea is to try and bring more evidence of the ecological and social benefits of this model, so it can be supported and incentivised to be carried out across regional areas.”
Cavalcanti Marques points out that while there is evidence showing that savanna enrichment works as a means to grow native bush foods and medicines – that it’s providing social benefits and increasing diversity of bush tucker plants – so far that evidence is strictly anecdotal.
“Through research you can actually prove whether or not this model is also contributing to things like restoration, and whether it is, for instance, contributing to carbon sequestration, carbon offsetting and that sort of thing,” she says.
“What I think is interesting about this savanna enrichment model is the principle can be applied to different types of country – the species you would incorporate would depend upon where you want to implement this model. Here, in this case study we are looking at with TAFE, we are looking at the pindan scrub – this tropical savanna – so the species reflects that local context.”
Pindan is a name given to the red soil country of the south-western Kimberley region, and the flora associated with it. The pindan forms a transitional zone between the wetter areas of the north Kimberley and the Great Sandy Desert to the south-east. It is a low, open woodland of scattered trees dominated by wattles, eucalypts and tall shrubs. Higher ground is home to paperbarks and larger trees.
The native species with the biggest potential to generate income for First Nations people in the Kimberley, including the pindan scrub region, is Terminalia ferdinandiana. It grows across northern Australia between Broome and the Gulf of Carpentaria in sandy soils and harsh terrain where other plants struggle to survive. The fruit is a traditional Aboriginal food and medicine known by several names including gubinge in the west and billygoat plum in the east. The name Kakadu plum was created to standardise the product name for the native-food industry.
“Kakadu plum has the potential to combat many prevalent diseases.”
The small, green fruit sells well in Australia as a gourmet bush-food ingredient for jams and chutneys. Local and global companies are also seeking Kakadu plum for cosmetic products (primarily skin care), nutraceuticals (health food and drink supplements) and as a natural food preservative.
According to some experts, Kakadu plum has the potential to combat many diseases prevalent in Western society: inflammation, cancer, diabetes and other afflictions. It has the highest known levels of Vitamin C of any plant in the world and is full of antioxidants. According to biologist Ian Cock of Griffith University, Queensland, people are starting to take notice of the plant.
“The more we work on this plant the more we find,” he says. “It has possibilities with Alzheimer’s [disease] and as a natural antibiotic to assist the old, sick and infirm in fighting bacteria. It has possibilities as a natural antibiotic in animal husbandry where there is a trend towards plant extracts instead of manufactured antibiotics that animals develop resistance to. It has major potential in many fields.”
A member of the Centre for Planetary Health and Food Security at Griffith University, Dr Cock says Kakadu plum may be the stand-out native plant that could provide value and income to communities, but others are ideal to rehabilitate the environment and provide medicinal benefits.
He cited Scaevola spinescens (also known as prickly fanflower, currant bush and maroon bush), which has potential to treat cancer, heart disease and kidney complaints. He said plants from the Eremophila genus (sometimes known as Emu bush) also have well-documented antibacterial and antiviral properties.
The native plant industry
Kakadu plum is gathered primarily from Aboriginal lands; often, it is Indigenous women who pick the fruit by walking through the bush after the wet season to harvest up to 20 kilograms per day from trees that grow to three metres. Around Darwin, non-indigenous pickers target crown land or pay a royalty for gathering on Aboriginal country; they can earn $10–20 per kg.
In some cases, plums are frozen and shipped away while other fruit are converted to powder (essentially, the plums are pulped and dried) and sold for $300–500 per kg. It takes about 10kg of fresh plums to create 1kg of powder. In a good year there is potential to harvest 40–60 tonnes of Kakadu plums from Western Australia, and 20–40 tonnes from the Northern Territory.
Courtenay believes Kakadu plum and other native plants, in combination with conventional food gardens, could underpin the economies of remote Aboriginal communities in Western Australia and elsewhere. Through practical training programs, he and Traditional Owners around Broome have planted more than 2,500 gubinge trees in the past 15 years. Nearly 600 trees were planted at Bidyadanga community, 180 kilometres south of Broome, and another 1,000 in a plantation-like situation at GoGo Station, about 400km east of Broome, near Fitzroy Crossing. The trees at Bidyadanga provide a regular harvest and income for the community; initially they were well-irrigated but now survive under normal seasonal conditions.
“Gubinge is our hero plant,” Courtenay says. “But across the north there are a number of other plants such as the wild mango or green plum (Buchanania obovata), the pindan walnut (Terminalia cunninghamii), also known locally as kumpaja, a very oil-rich nut.
“There is another nut which occurs in the desert which is called the desert walnut (Owenia reticulata) that has prized oil in it, very important to the traditional Aboriginal people from the desert; they applied the oil to their skin,” Courtenay says. “One of the old priests at Bidyadanga saw several of the people coming out of the desert, emerging from the traditional life. He said their skin shone like polished ebony and it was because they regularly applied oil of the desert walnut to their skin.”
These native plants have long been established at Balu Buru and form the backbone of Cavalcanti Marques’ program to prove the benefits of savanna enrichment; over time, there have been extra plantings in and around Broome, where First Nations people collect them to eat or to sell when in season.
“The horticultural techniques used for growing bush foods are very similar to those used in conventional horticulture, including market gardening,” Courtenay says. “Teaching these skills can contribute to the big-picture issue of food security [in] remote communities.”
In other parts of Australia native plants such as finger limes (Citrus australasica), Davidson plums (Davidsonia spp.) and lemon myrtle (Backhousia citriodora) are popular ingredients in foods, drinks, cosmetics and medicines, and demand is high.
However, in southern Australia there are relatively few First Nations people directly involved in the native-food, or bush-tucker, industry. In Australia’s north, hopes are high that native foods can become a mainstay of remote Indigenous economies.
The core of Cavalcanti Marques’ PhD research looks at social and ecological benefits of Indigenous involvement in savanna enrichment.
“That is really my focus,” she says. “Looking at what are the opportunities for communities and Indigenous groups to be able to implement savanna enrichment.
“Unfortunately, I don’t have findings or publications yet I can share about what the data tells us regarding the potential of savanna enrichment as a tool for land stewardship (namely restoration and carbon farming). However, anecdotal evidence suggests it might be an opportunity that fits in with the wants and needs of Aboriginal Rangers working on caring for Country.”
Cavalcanti Marques also works closely with the ARC Training Centre for Healing Country.
“I feel very frustrated by the fact that in Australia 2% of the Indigenous bush-tucker sector nationally is held by Indigenous people,” she adds. “It’s outrageous because the knowledge is 100% Indigenous knowledge – the whole viability of the bush-tucker industry in Australia relies heavily on this Indigenous knowledge.
“I think economic benefits are what stand out first and foremost – we know that the demand for bush tucker in Australia far outstrips supply, and we know that there is a big global interest in a lot of Indigenous products. There is not enough to actually meet that demand, so economically there is a big opportunity there – but I think that is only the tip of the iceberg in terms of social and cultural benefits.”
(Horti)cultural matters
At Balu Buru, Cavalcanti Marques and Courtenay work with Indigenous rangers and students planting, irrigating and recording details about the flora – information that forms the basis of the study project. They dig long, shallow channels in the red, sandy soil to lay poly pipes that will bring water to young saplings. These new plants exist in a time capsule, because they are alongside the same species that were established more than 15 years ago.
Recently, representatives of several Indigenous groups – the Nyangumarta Women Rangers, Bardi Jawi Rangers, Karajarri Women Rangers and the Kimberley Mineral Sands Rangers – visited Balu Buru and worked with Cavalcanti Marques and Courtenay to plant a variety of native species.
The rangers said there was potential for their communities in a variety of ways: to regenerate burnt country, establish seed banks and nurseries for native-food industries, bring native plants closer to communities so old and young people don’t have to travel long distances to gather and learn about traditional tucker, even to re-establish culturally important trees that have been destroyed by natural disasters, such as cyclones.
“Native foods can become a mainstay of remote Indigenous economies.”
Lynette Wilridge, Roberta Hunter and Lisa Toby, of the Nyangumarta Women Rangers, say they had Elders who were born under some of those large kumpaja trees along 80 Mile Beach, south and west of Broome. “They were very important places for our community,” the women say. “Cyclones took all that. We would like to grow those plants and put them back there. It won’t be the same, but it is important that we take those plants back to Country as a way to remember our ancestors.”
The rangers agreed elements of savanna enrichment could bring a community back to doing things they have been doing (traditionally) in the past, and help protect plants and animals as well as providing shelter and food.
Pat Torres, of Mayi Harvests, who helps develop native-food ventures, says governments should support First Nations groups and families who want to return to Country to grow and harvest bush tucker.
“Western agricultural methodology, including grazing by cattle and horses, has meant many native species have become extinct,” she says. “Aboriginal people are more aligned with a holistic way of looking after the land. Targeted burning and savanna enrichment is part of that.”
Torres says it is essential governments legislate to recognise and protect Indigenous knowledge, and provide as much infrastructure funding to remote communities as is provided to large corporates and pastoral interests.
Cavalcanti Marques says working at Balu Buru feels like a “very lucky occurrence”: “Having that site there that TAFE has looked after for so many years, having the ability to take students through and show them that this area we just planted out will look like in 15 to 20 years, people can experience the transformation before their eyes,” she says.
“They can examine mature, enriched savanna areas … you can see their eyes light up immediately when they start looking at the plants, identifying the plants, talking about how it compares to their Country. I think that site has power and impact. People can go there and not only get the training and the skills but get inspiration of what the potential is and what it could look like.”