Working in Tasmania stories
Ancient ash inspires fire plan
A core sample taken from a secluded lake on lungtalanana/Clarke Island in Bass Strait suggests Aboriginal people were using fire management there at least 41,000 years ago.
The discovery inspired leading fire ecologist David Bowman to propose a revival of ancient practices to make life in modern Tasmania safer.
Only a few weeks after the core was taken on Clarke Island there was a successful real-world test of Professor Bowman's concept on truwana/Cape Barren Island.
One volunteer, Terry Maynard, said the experience of using ancestral cool-burning methods to lower bushfire risk on the island made him feel "10 feet tall".
And there is economic potential to go with enhanced community safety and Aboriginal cultural pride.
By burning areas of the Arafura Swamp (nearly as big as Tasmania) at the start of the dry season, Northern Territory Aborigines prevent much bigger fires flaring up when the country dries out.
Reduced carbon emissions are recognised and paid for under Commonwealth carbon-abatement programs and the locals call this new income stream "smoke money".
"It's a beautiful example of Indigenous knowledge [creating] a market and an industry," the Chief Executive of Arnhem Land Fire Abatement, Jennifer Ansell, said.
At the other end of the nation, the Tasmanian Aboriginal Centre invited Professor Bowman of UTAS and the Professor of Natural History at the Australian National University in Canberra, Simon Haberle, to Clarke Island.
The landscape had been hit hard by an intense bushfire in 2014.
As expected, a core sample from the lake contained charcoal and pollen, enabling the scientists to reconstruct the island's fire history.
They were able to determine how often vegetation had been burnt and how intensely it had burnt over thousands of years.
Professor Bowman said: "We found a lake which had superb organic sediments in the base and we assumed that they were just from the last 10,000 years.
"We radiocarbon dated the sediments and we discovered, to our amazement, that these sediments actually stretch back [beyond] 40,000 years.
Professor Haberle said the dating suggested fire management had been introduced to the island at least 41,000 years ago.
The core sample showed how fire regimes on Clarke Island had changed substantially over the ensuing time.
"Part of that change was really due to the landscape management activities of Tasmanian Aboriginal people as they lived on those islands and used fire as a tool to manage the landscape," Professor Haberle said.
"What we see is that over most of the period of the record, frequent and low-intensity fires occurred on the island.
"This can really only happen through regular burning of the vegetation, most likely because of people lighting those fires and managing the landscape."
In his book The Biggest Estate on Earth, Adjunct Professor Bill Gammage, AO, built a powerful case for the concept of Aboriginal modification of Australia's landscape through controlled burning.
The Australian National University academic postulated — and provided impressive evidence for —his argument that there had been little wilderness in Australia in 1788.
The majority of the landscape that settlers described as "parklike", in fact, reflected a successful and sensitive land-management regime that had been implemented by uncounted generations across the fire-prone Australian landmass.
Fire was not simply a tool of fuel reduction or grass promotion, but was employed to ensure certain plants and animals flourished.
Plant and animal resources were kept abundant, convenient and predictable.
Professor Haberle said bushfires had become more intense on Clarke Island after Tasmanian Aboriginal people had left.
"When Europeans arrive there is a change in the fire regime and there are many very strong fires and, in many cases, catastrophic fires have occurred in the recent past," he said.
"Those fires are a result of ... changes in the land-management strategy."
Professor Bowman said: "Scientists have looked at various sediment traps, but nothing really of such quality and time depth in southern Australia. We are terribly excited about this core."
Andry Sculthorpe of the TAC's project team said: "Fire is something that was always used by Aboriginal people to shape the environment and to keep country healthy."
Professor Bowman said traditional low-intensity burning should play a greater role in today's fire mitigation in Tasmania.
"This would be, I think, a really great aspiration for Tasmania — to help a group of people who have had their culture disrupted by colonisation to rekindle their traditions and actually serve their society — our society — by making flammable, dangerous environments much safer," he said.
"This is getting quite urgent now because of the deteriorating climate conditions.
"We must learn from the past, we must learn from the first Australians.
"They obviously did something very clever, that they were able to sustainably coexist in a very flammable environment."
Even before Professor Bowman's proposal, the Tasmanian Fire Service (TFS) had been working with volunteer Truwana Rangers on Cape Barren Island to investigate the potential of integrating ancient and modern fire-management skills.
The Tasmanian Aboriginal Centre had been rekindling traditional burning on its land for about three years, leading up to the October trial on the island which had been handed back to the 600-strong Aboriginal community by the Tasmanian Government in 2005.
Volunteer ranger Terry Maynard told the ABC: "We've gone up to the Top End and learnt from the traditional burners up there how to 'cool burn' properly, so we can regenerate our land."
The TFS has been teaching the rangers about fire behaviour and the rangers have been teaching the TFS what they have learned about the "cool burn" techniques.
The rangers recently took part in remote-area fire-fighting training with the TFS in Launceston, learning various skills, including first aid and helicopter-assisted fire-fighting.
Two TFS personnel were involved in the experimental October burn-off.
Paul Catrell from the TFS told the ABC: "The fires that we've had here in the past have been quite destructive because the vegetation has been able to build up over a period of time."
He said the mosaic-style of "cultural burning" would help protect the community by reducing fuel loads as summer approaches.
Over 10 years, bushfires had burnt huge sections of the 4,370ha island which sits just south of Flinders Island, off the north-eastern tip of the Tasmanian mainland.
"You can go back in history and you can see that by doing this sort of practice that it stops those intensely devastating fires from occurring," Mr Catrell said.
"They know the weather patterns, they know the country, they know the fuel types, they know what they want to protect."
A "cool burn" fire is designed to move quickly through undergrowth without damaging plant roots or the earth. It helps native plants regenerate.
Mr Maynard said: "Instead of letting the hot fires go through, we've got to try to heal our land with cool burns, so we can get our land back to how it was."
The TFS hopes the Truwana Rangers can become first responders to fires not only on Cape Barren, but also on other nearby islands.
Fighting fires on remote islands is expensive, so having the rangers on site could be a big cost-saver and the volunteer rangers say they find the role empowering.
Mr Maynard said: "It's really important now that we've had the land handed back to show people off-the-island how we can look after our land and that we want to."
So a 41,000-year-old story may still have some time to unfold.
Footnote: The carbon dating of fire sediments on Clarke Island is, potentially, the oldest hard evidence yet of human presence in Tasmania.
Image courtesy of the ABC
5 December 2017, Edition 190