Fires set stage for irreversible forest losses in Australia
CGTN

Australia's forests are burning at a rate unmatched in modern times and scientists say the landscape is being permanently altered as a warming climate brings profound changes to the island continent.

Heat waves and drought have fueled bigger and more frequent fires in parts of Australia, so far this season torching some 40,000 square miles (104,000 square kilometers), an area about as big as the U.S. state of Ohio.

With blazes still raging in the country's southeast, government officials are drawing up plans to reseed burned areas to speed up forest recovery that could otherwise take decades or even centuries.

Smoke and rain mist mix in the air as cattle graze below burnt grass fields near Milton, January 5, 2020. /AP Photo

Smoke and rain mist mix in the air as cattle graze below burnt grass fields near Milton, January 5, 2020. /AP Photo

But some scientists and forestry experts doubt that reseeding and other intervention efforts can match the scope of the destruction. The fires since September have killed 28 people and burned more than 2,600 houses.

Before the recent wildfires, ecologists divided up Australia's native vegetation into two categories: fire-adapted landscapes that burn periodically, and those that don't burn. In the recent fires, that distinction lost meaning — even rainforests and peat swamps caught fire, likely changing them forever.

Flames have blazed through jungles dried out by drought, such as Eungella National Park, where shrouds of mist have been replaced by smoke.

"Anybody would have said these forests don't burn, that there's not enough material and they are wet. Well they did," said forest restoration expert Sebastian Pfautsch, a research fellow at Western Sydney University.

"Climate change is happening now, and we are seeing the effects of it," he said.

High temperatures, drought and more frequent wildfires – all linked to climate change – may make it impossible for even fire-adapted forests to be fully restored, scientists say.

"The normal processes of recovery are going to be less effective, going to take longer," said Roger Kitching, an ecologist at Griffith University in Queensland. "Instead of an ecosystem taking a decade, it may take a century or more to recover, all assuming we don't get another fire season of this magnitude soon."

Fire is a normal part of an ash forest life cycle, clearing out older stands to make way for new growth. But the extent and intensity of this year's fires left few surviving trees in many areas.

Already ash forests in parts of Victoria had been hit by wildfire every four to five years, allowing less marketable tree species to take over or meadows to form.

"If a young ash forest is burned and killed and we can't resow it, then it is lost," Bassett said.

Unlike grasslands, which see the vast majority of Australia's huge annual wildfire damage, forests are unable to regenerate in a couple of years. "For forests, we're talking about decades, particularly in more arid climates," Andela said.

Most forested areas can be expected to eventually regenerate, said Owen Price, a senior research fellow at the University of Wollongong specializing in bushfire risk management. But he said repeated fires will make it more likely that some will become grasslands or open woodlands.

Price and others have started thinking up creative ways to combat the changes, such as installing sprinkler systems in rainforests to help protect them against drought and fire, or shutting down forested areas to all visitors during times of high fire danger to prevent accidental ignitions.

That could involve planting trees in areas where they might not be suitable now but would be in 50 years as climate change progresses.

"We cannot expect species will move 200 kilometers (125 miles) to reach a cooler climate," said Pfautsch. "It's not looking like there's a reversal trend in any of this. It's only accelerating."

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Source(s): AP