Why is Tasmania burning, and why are scientists worried?

Over the past decade, dry lighting-caused fire instances have increased in Tasmania, which scientists say is linked to climate change.

On January 13, dry lightning strikes sparked off a series of fires in northwest Tasmania that spread quickly. So far, the fires have ravaged more than 107,000 hectares of land, according to the Tasmanian Fire Service.

As of Monday, there were 81 active fires across the state, of which, 26 are currently either uncontained or uncontrolled. Nearly a month after the fires started, many are still ablaze. One problem is that most active fires are located in remote, rugged areas of Tasmania. Moreover, some fires are burning in deep peat soil, Ted Lefroy, Director of the Centre for Environment at University of Tasmania, told Mongabay.

The trouble with peat fires — or fires that result from the burning of partially decomposed plant matter in wetlands — is that these tend to keep smoldering underground without becoming outwardly apparent on the surface. This makes it difficult for firefighters to detect and control the fires. The peat fires do become visible occasionally, Lefroy said, when the temperatures rise further and wind speeds increase.

To manage the active fires, over 180 remote area specialists from Tasmania Fire Service, Tasmania Parks and Wildlife Service, Australian mainland and New Zealand have been operating throughout the state. Given the enormous scale of the fires, firefighters have been focusing most of their efforts on human life and property such as farmlands, and critical infrastructure like major hydro-electric transmission lines.

While specialists are striving hard to control the fires, Tasmania’s woes are far from being over. The Tasmania Fire Service has planned four more weeks of firefighting operations, Regional Fire Chief Jeremy Smith told reporters. “There’s several fires that have the potential [to move],” he said.

“We’re putting sufficient resources on those fires to ensure that they don’t move. And also looking at other options so if the fire weather eventuates – those days where it is warm and windy, those days that Tasmania notoriously gets in February – that we have plans in place.”

Why are scientists worried?

The current fires have burned down around 11,000 hectares of the state’s United Nations World Heritage wilderness area. And this has conservationists worried.

One reason for their worry is that some of the burned area in the World Heritage region is home to unique vegetation found only in Tasmania. These include cushion plants, and conifers like the King Billy pine (Athrotaxis selaginoides) and the Pencil Pine (Athrotaxis cupressoides). Much of this vegetation is ancient, representing a time when Australia (and Tasmania) were still a part of Gondwana some 170-180 million years ago. These alpine trees — many over 1,000 years — are extremely sensitive to fire.

Different trees cope with wildfires differently. Some vegetation, such as Tasmania’s eucalyptus forests occurring at lower elevations, are adapted to wildfires. In fact, eucalyptus trees thrive in those conditions.

“Fire opens up the woody capsules that hold the seeds, which love growing on freshly burned soil,” David Bowman, a Professor at the University of Tasmania, told KQED in 2013. “Give a hillside a really good torching and the eucalyptus will absolutely dominate. They’ll grow intensively in the first few years of life and outcompete everything.”

In contrast, fires can be devastating for Tasmania’s slow-growing and long-lived, ancient native conifers like pencil pines that grow at high altitudes. These trees have successfully persisted for many years mainly because they grow in wet and cool regions of the state, where fires have typically been rare, low in severity, or spatially patchy.

Sometimes though, extreme dry and hot weather conditions have triggered massive wildfires that have devastated this fire-sensitive alpine vegetation. In 1960 for example, human-ignited bushfires burned down around 60 percent of the Central Plateau, including vast swaths of pencil pine stands. A study published in 2014 found that the 1960 fire killed one-tenth of the total population of pencil pines in the region. The loss of these pines has largely been irreversible, scientists say.

Researchers found, for instance, that pencil pine stands that were burned in 1960 are still almost completely devoid of live pencil pine trees and seedlings. Instead, the burned patches have given way to a community of more flammable vegetation, creating what researchers call a “fire-trap” that perpetuates fire, and prevents trees like pencil pines from regenerating.

So why do pencil pines or King Billy pines have trouble recovering after fire events? One problem is that they don’t produce seeds very often. These trees tend to produce seeds episodically, at an interval of five to six years,according to A. Malcolm Gill of Australian National Herbarium. Moreover, these trees typically begin producing seeds only after they reach a certain height (of around two meters). Since the trees grow very slowly, reaching these heights can take several decades.

Another problem is that fires destroy peaty soil, which has taken millions of years to accumulate. While surface fires destroy the above-ground parts of the trees, the peat fires incinerate the below-ground parts, which have the potential to help the trees regenerate. So re-vegetation of bare ground in these alpine zones can sometimes take centuries. In some cases, the vegetation may never recover.

The current fire is destroying some of the last large stands of pencil pines, King Billy pines, and Australia’s only winter-deciduous beech Nothofagus Gunnii. And these burned patches could have little chance of bouncing back in the future, conservationists fear.

The fires are also burning and killing wild animals. Wilderness photographer and bushwalker Dan Broun witnessed “devastated wildlife; burnt wallabies, dead wombats and the like” while hiking through the bushfire-affected regions in the Central Plateau in January.

Are bushfires “normal” in Tasmania? Or is climate change to blame?

Bushfires are common in Tasmania, and have been a part of Tasmania’s natural history. But the frequency and intensity of the fires — mostly human-induced — has changed over the years.

During early 1800s, for example, Aborigines are thought to have used low intensity and infrequent fires in Tasmania, most likely to flush game when hunting, or to create paths, according to a study published in 1998.

With the arrival of Europeans in mid 1800s, though, Tasmania’s fire regime shifted. Europeans used frequent — often extensive — fires to clear dense vegetation for their exploratory activities, and to strip the ground bare to look for mineral deposits. Many European settlers also torched vast areas of Tasmania’s rainforests to transform them to grasslands for cattle ranching.

Fires in Tasmania’s alpine region, however, have been infrequent. Occasionally, pastoralists and arsonists have set fire to the area, and bushwalkers have triggered some fires by accidentally leaving camp fires alight, or by burning toilet paper. Sometimes, lighting strikes have caused fires.

The declaration of the World Heritage Area in 1982, and regulation of campfires in the region has sharply reduced human-induced wildfires, Bowman writes. However, lightning-caused fires have increased over the last decade, he adds. The Giblin River Fire in 2013, for example, was one of the largest fires recorded in Tasmania, burning more than 45,000 hectares.

This increase in lighting-induced fires, he says, is due to climate change.

Scientists say that conditions for fire in Tasmania were ripe. 2015 had one of the strongest El Niño events on record, and a record-warm Indian Ocean, which helped shape very hot and dry conditions in Tasmania last year. Rainfall was below average across the state, and a record low in western Tasmania, according to Australian Government’s Bureau of Meteorology. Last year was also Tasmania’s second hottest year on record, behind 1914.

These extremely hot and dry conditions — attributed to changing climate — have “left fuels and peat soils bone dry,” Bowman writes.

“A critical feature of the current Tasmanian fires is the role of lightning storms – climate is not only creating the precursor weather conditions for the fires, it is also providing the storms that ignite them,” Bowman adds.

How do we deal with such wildfires in the future?

Scientists predict that as climate becomes warmer and drier, wildfires will become more common in the future. Controlling frequent and extensive fires will need adequate warning systems, resources, and aggressive fire management strategies, conservationists say.

First, fighting massive wildfires needs prioritizing.

“We have already sensibly decided that protection of property during fire events is less important than ensuring the survival of people,” Jamie Kirkpatrick, a conservationist ecologist at University of Tasmania, write in the Mercury. “We should also privilege the maintenance of ancient forest life over the protection of property. It is easy to rapidly rebuild houses and bridges. It is impossible to rebuild the Huon pine and King Billy pine forests that make Tasmania so special and attract people from all over the world to admire their beauty.”

Under predictions of a warming climate and frequent wildfires, David Bowman suggests moving vulnerable species to artificially protected environments, such as botanical gardens. “In the worse case scenario moving some species to sub-Antarctic island may not be far-fetched,” he wrote in the Conversation.

So far, the fires have spread to hostile geographic areas with limited access, and are expected to spread further. Given how unusual the conditions are, the firefighters’ response has been as good could be expected, Lefroy told Mongabay. But “while they can contain these fires, it will take soaking rain before they are all extinguished,” he added.

There needs to be more emphasis on remote area fire-fighting specialists, Lefroy and Andrew Campbell of Charles Darwin University wrote in an op-ed in the Conversation. Additionally, scientists say that wildfires need to be tackled more aggressively during the early stages of the fire using highly trained specialists with well-equipped aircrafts.

But this “would take more than money and kit,” Lefroy and Campbell write. “It would first require a change in policy, a different attitude to land management and a different attitude to risk.”

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