The Great Sandalwood Transect

Across a 1500-kilometre arc from the Gibson Desert to Shark Bay, researcher Richard McLellan is uncovering the ecological and cultural value of sandalwood. 

In the rangelands of Western Australia, there is a slow growing, hardy and iconic tree. When rain rolls in over the arid and semi-arid plains, the tree flowers, a scent is released. Wasps, ants, butterflies and other insects feast on the nectar.

The scent is earthy and sweet and if you break open the tree, deep within the heartwood, the fragrance becomes more profound, more aromatic.

It is the Australian Sandalwood tree (Santalum spicatum), the most commercially valuable tree in Australia.

Commonly found in incense, perfumes and soaps, and hugely popular overseas, Australian Sandalwood has become a pillar of WA's forestry industry. But while a lot of recognition has been placed on its commercial value, what of its ecological and cultural value?

That's where researcher Richard McLellan comes in. Richard has been investigating the role of hemiparasitic trees (meaning they derive some of their water and nutrients from other plants) in desert communities for his PhD at Charles Sturt University.

Alarmingly, he has found Australian Sandalwood appears to be going extinct in the wild.

It is in such rapid decline that he is calling for it to be listed as a threatened species in Western Australia. Commercial exploitation, land clearing, grazing and climate change are all partially to blame, as is the loss of native animals that helped disperse its seed.

“One of the reasons sandalwood is not regenerating in the rangelands is because it's lost its seed dispersers – the Boodies and Woylies – which behave a bit like squirrels, collecting fruit that falls underneath the tree, taking them away, and burying them as a form of scatter hoarding,” says Richard.

When feral cats and foxes were introduced to the rangelands, Boodies (Burrowing Bettongs) and Woylies (Brush-tailed Bettongs) disappeared, setting off an ecological domino effect.

Unfortunately for sandalwood, it doesn’t just smell good, it tastes good too. Richard’s research found that when sandalwood does germinate it is highly likely to be eaten by animals like goats, sheep, cows, camels, rabbits, and kangaroos.

Its decline is further influenced by the impacts of climate change; without successive years of sufficient rainfall, the plant fails to regenerate.

“You lose those seed dispersers, and suddenly you've lost 80 years of regeneration of sandalwood. Once we lose sandalwood, we will lose some of the pollinators that depend on the nectar. What's next?

Keen to ground-truth this for himself, Richard came up with a plan to survey sandalwood at 12 different locations over seven weeks in a 1500km arc from the Gibson Desert to Shark Bay. He named it ‘The Great Sandalwood Transect’ and embarked on the ambitious field project with his PhD supervisor, Professor David Watson.

Sites included Bush Heritage’s Charles Darwin, Hamelin Station and Eurardy reserves where Richard has been monitoring sandalwood for over two years to assess its ecological importance.

“Santalaceae species are all hemiparasites and produce a huge amount of high-quality litter,” he says. “As a result, there's always insects and grubs getting into that litter to make use of the nutrients and that attracts a lot of birds, reptiles and even mammals.”

While sandalwood populations are flowering and producing seeds at Bush Heritage reserves – having benefited from the exclusion of livestock – Richard is yet to see regeneration of young plants; a vision he would like to see realised in the future.

Further east on the Great Sandalwood Transect, another man shares a similar vision. When Richard visited the Birriliburu Indigenous Protected Area (IPA), 6.6 million hectares in WA’s central deserts, he met with Martu man and sandalwood harvester Clinton Farmer.

Despite protecting some of the oldest sandalwood trees in the world on his country – ‘mother trees’ which are up to 300-years-old – Clinton, too, is worried that overharvesting and climate change are threatening the future of sandalwood.

Clinton was born into a long history of sandalwood harvesting. His father, Ken Farmer, walked out- of the Gibson Desert in the early 40s with the first contact desert nomads. Seeing some difficulties in the town, Ken began harvesting in 1977 as a way to keep his people connected to country.

“Sandalwood is special to our culture: it’s a medicine, it's for smoking, and for calming the mind when making important decisions,” says Clinton. “If there was a cut, or spear wound, or skin infection, the old people would warm the seed up, grind it on the grinding stone and put it on the wound.”

Clinton took on the responsibility of running the business, naming it after the Martu word for sandalwood, Dutjahn, and to this day, has carried on his father’s mission.

“Our people’s deep spiritual connection with the land is passed down in the blood from generation to generation, that’s how we survive, with that strong relationship. We treat the land like it’s our relative. It’s our family. It’s our people. Because when our people pass on, that's where we return to − to the land.’’

For Martu people, sustainability is a way of life, and as the threats that come with climate change increase, Clinton recognises the need for smart, collaborative land management to respond to it.

Ultimately, he would like to see country replanted and a strong population of sandalwood thriving for future generations. Thankfully, he’s not alone. As Richard sees it, sandalwood’s fate is not yet sealed.

“Every landholder and Aboriginal ranger program we’ve encountered on the Great Sandalwood Transect wants to be a part of the solution.

“We’re keen to see those people empowered to plant sandalwood, nurture it, and keep it on their properties. Hopefully my research can contribute to that.”