In Australia, there are natural fires happened in each year for long, ling time ago, called bushfire. Bushfires still happen each year and the latest bushfires situation is still in risk situation that Australian people need to keep their eyes always on. Here is an example of bushfires occured in Australia.

TRANSCRIPT

NARRATION
Bushfires can bring devastation… and they also bring new life…

DR PAUL WILLIS
It’s wildly understood that fire is a natural part of the Australian environment but what is a natural fire regime for bushland like this? And what role will people have to play in the future burning of Australia? It’s time to take a look at the science behind the puff and bluster.

NARRATION
Scott Mooney has been looking at charcoal trapped in lake and swamp sediments – a record of burning in Australia stretching back more than 40,000 years.

Dr Scott Mooney
We’ve discovered that actually there’s a whole lot of history, pre-history if you like that we only imagined.

NARRATION
It’s commonly thought that the greatest influence on fire regimes is aboriginal firestick farming. While that may be true for more recent times, Scott’s research indicates a much more complex story. There’s very little association between the archaeological record and the fire record. So the last glacial maximum was about 20,000 years ago. Over the last 15000 years fires have become more frequent as the vegetation recovered from the last ice age.

Dr Scott Mooney
I believe that the dominant signal in this record is a climatic signal.

NARRATION
The vegetation responds to changes in climate and the climate sets the conditions for fire.

Dr Scott Mooney
It doesn’t matter which way the change is, whether it’s wetter or drier or hotter or colder, the change itself seems to drive fire in our landscape

NARRATION
Chris Lucas has been looking into future changes in climate.

DrChris Lucas
Climate and weather are the main drivers of bushfire risk /. Everything else follows from the weather and the climate.

NARRATION
And the hot topic at the moment is the effects of the Indian Ocean Dipole. In the negative phase there’s cool water in the Indian ocean and warm water off the coast of Australia bringing rain. In the positive phase it’s the opposite – bringing drought to southern Australia

DrChris Lucas
The positive dipole which is the bad one for causing drought in southern Australia tends to occur with an El Nino quite often.

NARRATION
El Nino also brings dry weather, and in recent years this double whammy has been occurring more frequently creating ideal bushfire conditions

DrChris Lucas
We are starting to see the effects of climate change. …extreme days are occurring more frequently,

NARRATION
Based on current climate trends we can expect a 10% increase in fire danger days by 2020 and up to 40% increase by 2050. So what’s to be done? We can’t control the weather or the climate, the only lever we really do have is fuel. So it would seem some sort of burning will be necessary. In the aftermath of Black Saturday a lot of people had strong opinions about bushfires ….

DR PAUL WILLIS
It seems like everyone’s got an opinion and the debate is polarised between those that don’t want to burn anything and those that want to burn everything. But where’s the science?

Prof. Mark Adams
I think we’ve got to start from the point that these forests are supremely well adapted to fire.

NARRATION
Professor Mark Adams has been studying the vulnerability of different forest types to fire.

Prof. Mark Adams
If a mountain ash forest were to be burnt in a bushfire twice in reasonable short succession we could well lose it. And so that’s one of the reasons why we don’t advocate the use of prescribed fire in mountain ash forests. But in the other forests, in Victoria we’ve got more than three million hectares of foothill forest where we can use prescribed fire on a regular basis.

NARRATION
And after only seven months since Black Saturday, the foothill forests are showing signs of life..

Prof. Mark Adams
This is an example of areas of forest that we can still use fire in, very safely, but we’re getting up towards the limit. These forests produce seven tonnes of fuel a year quite easily and as you can see recovers superbly well after fire.

NARRATION
But how often should a forest burn? No-one from a scientific point of view is advocating a scorched earth policy of burning every year. On the basis of the data it means something of the order of five year return periods for fire.

NARRATION
Forest ecologists Patrick Baker and Rohan Simkin’s field site is right next to Marysville – the epicentre of destruction for the Black Saturday fires.

Dr Patrick Baker
Yyou can see there’s some of the fires, this 2009 fire got into the forest back here..

NARRATION
How these forests respond to fire is part of their study..

Dr Patrick Baker
When you have this very heterogeneous landscape in terms of the response to the fire burnt in some places didn’t burn in other places and along these streams you have a lot of these trees seem to have survived.

NARRATION
It’s all about working out how frequently a particular forest would naturally burn – or if it should be burnt at all.

Dr Patrick Baker
Vegetation types have different fire intervals, so different vegetations burn more often and others burn less often.

NARRATION
It’s this variability between vegetation types that makes fire management so tricky, and although Patrick doesn’t agree that there should be a blanket rule to control burn, he is realistic….

Dr Patrick Baker
The forests now are not in an ecological bubble, there are people who live in the forests. Your fuel reduction burns may have to be more aggressive in order to try and minimise the risk, realising that it’s not possible I don’t think to eliminate the risk, you have to remember there’s a huge pool of fuel on the forests that is not being reduced and that’s what’s up in the crowns of the trees. And if you get fire into that when you have the extreme weather conditions that we had this year, all the fuel reduction, …… burning in the world will do nothing.

NARRATION
and Patrick understands those risks…

Dr Patrick Baker
Living here in, in Selby where we have a wooden house and we’ve got lots of trees around, I have 5 kids. We have no illusions that we would stay and protect this house in any way shape or form.

Dr Paul Willis
The forest ecologists might disagree about the frequency with which certain types of bush should be burnt but they do agree that controlled burning should take place where appropriate. They also agree that no amount of hazard reduction burning would have prevented Black Saturday.

Prof. Mark Adams
That day, with in excess of a hundred kilometre an hour winds, temperatures in excess of 45 degrees, ah there was no way that we were going to stop that bushfire just because we had some prescribed burning.

Dr Patrick Baker
As we saw this year in 2009 you’ll have fire moving through large areas and with extraordinary force because you have a huge amount of energy and biomass in the crowns of those trees. It’s those fires that are so dangerous.

Since bushfires still occurs in every year and it surprisingly increase at large numbers of this risk situation that affected to Australian’s natural and world’s climate. We need to take care of them closed up and try to prevent every calamity that will be occur in the future at the best effort we can.

Story Contacts

Dr Scott Mooney
School of BEES
The University of New South Wales

Professor Mark Adams
Faculty of Agriculture
University of Sydney

Dr Patrick Baker
Monash Forest Dynamics Lab
School of Biological Sciences
Monash University

Dr Chris Lucas
Research Scientist
Bureau of Meteorology