When bushfires burn through the spinifex plains on Ethabuka and Pilungah reserves, arid species find refuge in Gidgee woodlands that are as vital to their survival as they are threatened.
When Glenda Wardle first stepped onto the red sands of Ethabuka Reserve, Wangkamadla country, in 1998, she had no idea of the scientific journey she was embarking upon.
“Back on that very first trip, my initial impression was awe at the amount of plant life in Australian deserts – it’s not just grasslands, there are lots of shrubs,” she says.
“Our idea of deserts being stark, barren places is a little different to the reality in Australia.”
Glenda and her colleague Chris Dickman lead the University of Sydney’s Desert Ecology Research Group, which has been studying Bush Heritage’s Ethabuka and Pilungah (formerly Cravens Peak) reserves for over 30 years. Their dataset represents one of the longest-running studies of any arid system in the world.
At the heart of Glenda’s research are two ecosystems that have an intriguing relationship to one another: Georgina Gidgee Woodlands and Spinifex Grasslands. The former is dominated by the gnarled forms of slow-growing Gidgee trees (Acacia georginae), and the latter by the spikey, circular mounds of the hummock grass, Triodia basedowii, also known as spinifex.
In isolation, these ecosystems each support many species: Spinifex Grasslands provide food and shelter for a huge diversity of reptiles, small mammals and seed-eating birds, while the woodlands provide habitat for over 80 bird species. But when the woodlands occur alongside the grasslands, as they do on Ethabuka and Pilungah reserves, they take on a whole new role.
Gidgee Woodlands are usually found in lower swale areas between dunes and are generally quite resilient to fire. As a result, they become safe havens for desert animals fleeing grassfires and the mouths of the hungry predators that are attracted by the smoke.
“After flooding rain, the grass grows rapidly then dries out and we anticipate fires that burn the spinifex and create a riskier environment for fauna,” says Glenda. “When that happens, we noticed that the Gidgee Woodlands next door provided shelter and food resources and acted as a refuge for fauna and plants.”
Worryingly though, the future of Gidgee Woodlands is uncertain.