AUSTRALIA – The amount of vegetation burnt by fires caused by lightning strikes in Tasmania’s world heritage area has increased dramatically this century, according to new research led by the University of Tasmania.
The study, published this month in the academic journal Fire, warns the state’s heritage forests face rising threats because of the tendency toward drier summers and that the probability of “catastrophic” fires could increase as a result of more fuel igniting from lightning strikes.
In 2016, parts of the world heritage area were devastated by fires, many ignited by lightning strikes.
Researchers at the University of Tasmania looked at historic fire data collected by the Tasmanian parks and wildlife service from 1980 to 2016.
The records detail the number of fires each year, the area burnt and what caused the fire.
From the year 2000, they found an increase in the number of lightning-caused fires and an increase in the average size of the fires, “resulting in a marked increase in the area burnt”.
Their data shows only a few fires caused by lightning were recorded in the 1980s and 1990s, compared with almost 20 that were recorded in 2015-16.
There were major fires caused by lightning in 2000-01, 2006-07, 2012-13 and 2015-16.
“Lightning is now responsible for the majority of the area burned in the TWWHA [Tasmanian wilderness world heritage area],” they state.
Fire ecologist Jenny Styger, the paper’s lead author, said: “Something changed about 2000.
“It was the tipping point at which lightning started to become the predominant cause of fire ignition.”
The researchers were unable to determine if the reason for this was because there had been an increase in lightning strikes, or if drier fuel in the world heritage area was making it more likely a fire would start because of a lightning strike.
They said this was because western Tasmania does not have reliable historic data on the detection of lightning strikes.
But Styger said it was a significant issue because many of the fires in the world heritage area occurred in remote forest with no road access, making them difficult to detect and extinguish.
“This is going to impact how we think about fire management for the world heritage area and it’s going to become a much greater threat with climate change,” she said. “It’s going to be a really significant issue going forward because the world heritage area has lots of areas that we don’t want to burn.”
In 2016, an Australian Senate inquiry examined the fires in remote Tasmanian wilderness in January and February of that year.
The Tasmanian Greens senator Peter Whish-Wilson said the new research showed “climate change’s impacts are here now and this is another reminder of the need to urgently reduce emissions”.
He said the inquiry had considered whether an increase in fires caused by lightning may have contributed to the destruction in 2016.
“To have this confirmed by this study should send shockwaves through the conservation community,” he said.