The surprising history and rich diversity of Australia's deserts
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Their names spark both fear and awe: The Gibson, the Great Sandy, the Little Sandy, the Simpson, the Strzelecki, the Tanami.
These deserts are legendary in the Australian story and a big part of our national mythology.
There's also a collection of lesser-discussed regions: The Barkly Tablelands, the Channel Country, the Flinders Ranges, the Nullarbor, the Pilbara.
Together, landscapes like this form Australia's arid zone, or what we might call the outback.
These areas represent 5 million square kilometres, or three quarters of our island continent.
But despite this, the history and complexity of these landscapes aren't widely known.
One ecologist is on a mission to change this.
Dr Steve Morton is an ecologist who worked for years with the CSIRO investigating the arid zone and recently released a book called Australian Deserts.
He says Australia is so arid because "the continent is so old".
"It drifted from its original position … attached to Gondwana into the 'subtropical zone', where the rainfalls are inherently lower and more uncertain," Dr Morton tells ABC RN's Saturday Extra.
He says the drift started "about 20 million years ago", and subsequently "we began to dry out [and] the rainforest retreated to the east coast".
"So it's our geological history which delivered us aridity … we have a long history of being dry."
And for tens of thousands of years, Australia's Indigenous people have lived and thrived across these dry areas.
"[I have such] humility at the extraordinary cosmology that Aboriginal people developed to explain the formation and the functioning of the country that they belonged to," Dr Morton says.
The term 'desert' can conjure images of huge sand dunes without a tree in sight, like the Sahara. But Australian deserts are very different.
"People are surprised. Yes, it's called a desert. But when you come and visit, for much of that 5 million square kilometres, it's actually a shrubland or a grassland or even a woodland," Dr Morton says.
"The very word desert is rather confusing, because often you're looking at a shrubland. It's only a desert so-named in Australia, such as the Gibson, because our society, the white society, has not found a way to make use of it economically [like farming]."
Dr Morton says the makeup of the arid zone is caused by an erratic climate.
"Aridity here is characterised by extreme climatic uncertainty," he says.
"The uncertainty of rainfall delivers not just long, dry periods, but occasional periods of flooding rain."
Once-dry parts of Western Australia, for example, have been experiencing severe flooding.
And this pattern means Australia's deserts can be surprisingly diverse places.
All over Australia's arid zone, there are different plants, which Dr Morton says are evolutionary marvels.
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He says on one end of the spectrum are the "perennial plants" which "through physiological adaptation … can withstand the harsh, long dry spells that go on for years".
These plants can be "sustained by minor trickles of moisture brought up from soil moisture stores, by deep roots".
Then at the other end of the spectrum are the "ephemeral plants" that "don't bother to fight this – they just create seeds, which last for years, grow after a pulse of rain, then set more seeds and disappear".
It's the same story with animals.
Dr Morton points to insects like termites and ants, that "have colonies they can bring back supplies to, which allow them to harvest when abundance is there, and then sustain themselves by locking down … during the intervening dry periods".
Then there are animals which make use of the desert when there are extreme weather events, like floods.
"They are called the 'boom and bust species' … [It's a] strategy that is almost unique to Australia," he says.
"Because you have these massive peaks of production and biological activity, there's a group of organisms that have found ways to hop from peak to peak – use it when it's there and bail out when it's not."
He points to the "pelicans that fly to Lake Eyre and use the resource when it's present" as a classic example.
Thousands of pelicans flock to South Australia's Lake Eyre when it's flooding, before departing to another area of the country.
If you've ever flown across Central Australia, you may have noticed the twisting and turning lines below – great squiggles that cut through the landscape.
Dr Morton has an explanation for that.
"When you get heavy rain, the water moves across the landscape – it runs to the lowest point," he says.
"That whole process carries with it nutrients and soils, and creates moisture stores."
"So the run-on and run-off hydrology of inland Australia is the dominant ecological force. That's what creates the landscape pattern that you see when you're flying across it."
After years of studying and experiencing this country's arid zone, Dr Morton urges everyone to reacquaint themselves with the regions of our huge interior.
"It's immense and vast, and it seems so uncaring of human beings. But if you choose to look at it carefully – you can find a way into it and understand that immensity."
It's an immensity that's diverse, complex and uniquely Australian.
"This has been my passion for 30 or 40 years, to try and understand this place on its own merits … [I'm] humbled and awed by the place," he says.
"This is certainly more than simply an intellectual interest, it's an emotional attachment. I love it."
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The surprising history and rich diversity of Australia's deserts – ABC News
