Surveying for Sandalwood
Decreasing numbers of Australian Sandalwood trees across their known range is the sad legacy of an unsustainable harvest that began across South Australia a century ago.
Back then, during the darkest years of the Great Depression, many supplemented their income by harvesting Sandalwood that would then begin a long journey to Asian markets.
The outcome of a recent survey for Sandalwood (Santalum spicatum) at Bush Heritage’s Bon Bon Station Reserve, south of Coober Pedy, is consistent with this history – as well as what many researchers have found throughout the country’s entire Sandalwood range. It is a species under threat on a number of fronts.
Unsustainable legal harvesting in Western Australia is just one. Add to it illegal harvesting, loss of seed dispersers, fire, drought, climate change and grazing by kangaroos, rabbits, goats, sheep, cattle, camels, horses, and donkeys and you have a species that is now threatened in South Australia. The penalties for illegally harvesting the fragile plant vary from hefty fines to imprisonment.
Sandalwood is listed globally on the IUCN Red List of Threatened Species as Vulnerable and is currently being assessed by the Australian Government to determine if it should be listed as a threatened species across its entire range.
Bon Bon Station Reserve is on the northern, outer edge of sandalwood’s distribution in South Australia, but records indicated there were ‘one or two’ trees scattered around the property.
A baseline survey planned to better document the number, age and condition of the plants on the property resulted in a full week of May spent criss-crossing the reserve looking for, and documenting, Sandalwood trees for adjunct Research Fellow Charles Sturt University Richard McLelland and long-time Bush Heritage Australia volunteers Garry McDonald and Anne Williams.
While they didn’t find huge numbers, they did find enough Sandalwood to brighten the day for Bush Heritage ecologist Pat Taggart and SA Healthy Landscape Manager Graeme Finlayson.
Richard McLelland said most of the ‘stands’ of Sandalwood consisted of just one or two trees more than 100 years in age, with a few younger trees providing a glimmer of hope.
“Some were growing directly under parent trees, where they are almost certain to perish, but others were found growing in relatively moist creek-lines, where seeds had been washed downstream from a parent plant and buried where creek-bed soil moisture levels provided a higher likelihood for survival” he said.
“We were heartened by the minimal evidence of grazing impact on all of the plants we found, no doubt a tangible benefit of the sustainable conservation management being implemented on the reserve.”
He said its presence on the reserve potentially makes Sandalwood an important indicator species for assessing landscape recovery, and a valuable on-site threatened species to incorporate into reserve management planning and interventions.
The missing link in the Sandalwood story is that of digging mammals like Bettongs, now extinct across much of the species range. These marsupials provided an ecosystem service by burying the seeds and promoting dispersal and germination. This service is now lost.
“Slowly disappearing from the wild in the rangelands, Sandalwood will likely only persist into the future across much of its former range if it is proactively cared for by land managers, and replaced in carefully planned re-seeding, revegetation, and restoration programs,” Richard said.
