Australian regional ecosystems are losing resilience

Tourists flock in to go fishing. Patches of pristine bushland pull in campers. Thriving crops keep the wheels of industry turning.

Regional communities may feel confident their slice of Australia is doing fine. But new research warns it all may already be doomed if we don’t take a closer look.

“The Millennium drought really changed the dynamics of Australian agriculture,” says Flinders University Professor Corey Bradshaw. “And we are already farming largely marginal land.”

Bradshaw and a group of international researchers have built replica ecosystems and run them through one of Europe’s most powerful supercomputers. The idea is to understand the domino effects induced by the extinction of any given species.

New research published in the journal Science Advances demonstrates that losing even one plant or animal can have devastating implications for any given region. And that’s also true on the national and global scale.

“We’re already on the edge,” the professor of ecology told Cosmos. “The more we degrade those ecological functions that provide us with water flow, soil fertility, nutrient exchange and pollination, the more we will see the abandonment of farms and country towns.”

This risk is widely known.

But the processes driving the loss of these vital ingredients of life need to be better understood.

Professor Corey Bradshaw (Pic Flinders News)

“We know an economy that has many different components can withstand shocks from global events much better than an economy based on one or two major industries,” Bradshaw says. “It’s the same for an ecosystem. If you have just a few species doing the big jobs, when a shock comes along – a drought, fire or flood – the whole thing can suddenly crumble into a heap.”

For example, we know koalas eat only a handful of different eucalyptus trees – manna gum, swamp gum, long-leaved box and brown stringybark. And we see the remnant forests of these still being felled.

And some fruit growers are swimming in pest insects because the local southern bent-wing bats have gone?

The Bogong moth is also in rapid decline. It’s one of the primary food sources for the mountain pygmy possum, which are critically endangered.

“Now they’re losing a vital food source,” Bradshaw says, “So it’s very possible that we could lose the possum. But if we can save the moth, the possums will have a better chance.”

Almost all Australian regional ecosystems are losing such resilience, Bradshaw says. Where once a wallaby may have had three types of berry bush to feast on, it may already be down to one.

But simply planting more bushes won’t solve the problem.

More in Cosmos: Regional ecosystems: Bent-wing bats and Bogong moths.

Bats carry seeds and pollen. Bugs shift nutrients. Worms turn the soil.

Remove just one link in this ecological economy, and the whole system is put under strain. Though that may not be immediately apparent, Bradshaw says.

That’s why regional bird watchers, plant lovers and ecological groups need to be on the lookout, he warns. As well as local tourism businesses, farmers and councils.

Satellite photos are readily available via Google and the ESA Sentinel project. These can be used to track tree removal and waterway changes over the past 20 years for just about anywhere on the globe.

But nothing beats local knowledge.

“It’s about community and peers,” Bradshaw says. “If my next-door neighbour of 40 years says, ‘look mate, you shouldn’t cut down that row of trees because I need the bees’, I’m more likely to listen.”

And it has to be more than just about conserving what you have left, he says.

It’s about identifying what’s gone. Understanding the implications. And replacing the missing links.

“Your patch of forest in the back paddock may already be doomed,” Bradshaw explains. “It’s probably too far from the patch that has the right kind of bird or possum for it to regenerate, for example.

“So if we can start connecting up all these little fragments of forest, if we can start putting back some of the missing species, it may be enough to keep it all going. But only local communities can get enough of these things off the ground to make a difference.”

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