The words green and desert do not usually go hand in hand. But in 2010, the description couldn’t be more fitting. It’s a rare event, but when the rains arrive in Australia’s central deserts, the seemingly desolate environment erupts with life.
Now, months after the February and March saturation of Western Queensland, the effects are starting to take hold.
For Professor Chris Dickman, University of Sydney Ecology Professor, Institute of Wildlife Research Director and Desert Ecology Research Group (DERG) founder, it is a particularly rewarding occurrence. After 20 years of continuous research in the Simpson Desert, this is only the fourth ‘boom period’ induced by heavy rain he has experienced.
And it’s at times like these, according to Dickman, “everything’s moving”.
“Water surged down the river channels and as it did, it carried with it organic matter and debris, providing the water, nutrients and all the material necessary for a lot of plants to germinate,” says Dickman.
As deeper-rooted perennial species like the Coolabahs and Emu Bush recharge and flower, birds and insects have followed.
Dr Glenda Wardle, fellow DERG leader, Botanist and Senior Lecturer at the University of Sydney, says resources from the germination of annual plants will also flow onto the small mammals and reptiles.
But boom periods are not long-lived. The birds, according to Dickman, will be around in large numbers until the seed resources disappear in a few months. Rodents will increase to a peak around September.
“Next year, numbers will start coming down,” says Dickman.
And this is not just the result of drying conditions. Predators like foxes and cats are also attracted to the abundance of life in the desert. Even the Mulgara, the biggest of the predator marsupials, is vulnerable.
“They’ll eat rodents, Mulgaras and everything else and hang about until dry conditions prevail again,” says Dickman.
Predators are also the focus of a DERG study looking at the effects introduced species like the red fox have on small mammals, lizards and the broader prey community. Their other main study, focused on climate, seeks to look at how ecological systems, including plant-pollinator interactions, respond to extreme events, like wild fire.
As they celebrate 20 years of a long line of projects, Dickman and Wardle are nowhere near experiencing their last ‘boom period’. When Dickman first set out to the Simpson Desert in January 1990, he thought they’d know all they could about biodiversity in Australia’s arid dry-zone after five or six years. That was two decades ago.
“After the 1991 rains, it became apparent it was a much more complex system, with many more species, interactions and chance effects than we’d ever appreciated to being with,” he says.
Like Dickman, Wardle thinks it’s a landscape worthy of long-term study. “There are very few systems in ecology when you can work on all levels simultaneously and get a handle on how diversity functions,” she says.
But with every ‘boom’ period there comes a ‘bust’: a cycle that, according to Dickman, characterises inland Australia.
Predictions for arid Australia are that we’ll have longer dry periods, punctuated by even bigger boom events in even greater amounts than currently, says Dickman.
“We’ve got at least an inkling of how the boom and bust system works at the moment,” says Dickman. “We know some species will be OK with this. Some will spend more time under ground. Others, we’re not so sure about.”
For Dickman, studying how species and ecological communities cope in different conditions, in light of climate change, is crucial.
But even in dry times, Dickman recognises the desert environment as a place that is “bursting with life.”
“In the height of a dry summer the dunes are still covered with the tracks of small mammals, lizards, snakes and birds,” says Dickman.
“There’s a richness that hasn’t been great affected by human activity.”
With the Desert Ecology Research Group showing no sign of slowing down, Dickman prepares to look back on their progress. The Some Like It Hot public talk on 12 August is a chance to share what has kept him busy all these years.
Sydney Science Forum – Some Like It Hot
Date: Thursday 12 August 2010
Time: 5.45pm – 6.45pm
Location: Eastern Avenue Auditorium, The University of Sydney
Bookings: Register online: www.usyd.nicheit.com.au/science/science_forum/ or via email:firstname.lastname@example.org or phone: (02) 9351 3021.