Two myths about climate change and bushfire management are often repeated in the media:
1. Because of global warming, Australia will be increasingly subject to uncontrollable holocaust-like “megafires”; and
2. Fuel reduction by prescribed burning must cease because it releases carbon dioxide into the atmosphere, thus exacerbating global warming and the occurrence of megafires.
Both statements are incorrect. However they represent the sort of plausible-sounding assertions which, if repeated often enough, can take on a life of their own and lead eventually to damaging policy change.
I’m paraphrasing from an important new report entitled ‘Bushfires, Prescribed Burning and Global Warming’ by Roger Underwood, Chairman of the Bushfire Front, David Packham, Senior Research Fellow at the School of Geography and Environmental Science, Monash University, and Phil Cheney, Honorary Research Fellow, CSIRO, Canberra.
The authors consider in detail at the carbon balance in relation to fire in the three most typical Australian ecosystems: tropical grasslands, tropical/subtropical savannahs and tall forests and conclude:
1. Although the situation is almost carbon-neutral, all fires in tropical grasslands actually sequester some carbon in the form of “black carbon” which is incorporated into the soil;
2. Over time, the carbon balance of fires in tropical and subtropical savannahs is also just about neutral. In some years more CO2 is emitted to the atmosphere from fires than is absorbed by post-fire regrowth, while in other years more carbon is taken up by regrowth than is lost to the atmosphere from fire (including prescribed burning and wildfires).
The management approach that will optimise storage of carbon in Australian savannahs is one of low-intensity, early dry-season burning under mild weather conditions. This protects the overstorey trees and woody shrubs which are consumed by hot late-season fires.
3. Tall forests store carbon in tree trunks, bark, branches and roots, in woody shrubs and mid-storey vegetation and in the litter and accumulated organic debris on the ground. Eventually all old trees begin to decay from within, and in the absence of fire, the accumulated litter on the forest floor begins to rot away. At this point, the rate of release of carbon through decay exceeds the rate of storage of carbon by new growth. Thus Australia’s “old growth” eucalypt forests eventually stop being a carbon sink and become a source of CO2.
Fuel reduction by prescribed burning employs low-intensity fires lit under mild weather conditions at a time when there is still some moisture in the fuel. This ensures that the flames are generally less than a metre high and the fire is confined to the surface layer of fine fuel and the green material in the low shrubs. A properly managed prescribed fire will be conducted at a time when organic matter (including charcoal) in the soil will not burn. The ideal prescribed burn consumes only the surface fuels, leaving behind a layer of ash protecting the soil and the heavy logs.
The amount of CO2 released by a low-intensity fire is small and the store of carbon on the forest floor is rapidly replaced as the fine fuels re-accumulate and the low shrubs regrow. By comparison, a hot summer bushfire burning under drought conditions will consume all of the surface fuels, including large logs and organic matter in the soil which may have accumulated carbon for thousands of years. An intense summer bushfire will even consume the canopies of the tallest trees. The amount of CO2 produced by a fire is directly proportional to the total amount of fuel consumed in the fire. Thus a hot summer bushfire [in Australia’s tall forests] will release massive amounts of carbon.
The authors conclude that from the point of view of carbon storage in grasslands, savannahs and tall forests, the best management approach is one in which large high-intensity wildfires are minimised by periodic prescribed burns carried out under mild weather conditions.
The authors also examine the alarmist concept that “global warming will lead to unstoppable megafires”. They observe that if the current climate change models are correct, there will only be an increase in average annual temperatures of between 2 and 4 degrees over the next 100 years. The effect of this on bushfire behaviour, by itself, will be trivial. Fire intensity is far more significantly affected by fuel quantity, fuel dryness and wind strength, than it is by temperature.
Some climate change computer models also suggest a significant reduction in rainfall, leading to increased fuel drying and increased fuel availability at lower temperatures. This is the same effect as that of drought, a phenomenon which is common in Australia. Drought does result in more intense fires…..but only if nothing is done to reduce fuels before the fire occurs.
The factor which “doomsday” commentators ignore is the opportunity for land managers to get in first, and reduce fuels before a potential megafire starts. In other words, the potential megafire can be forestalled, simply by the adoption of a program of fuel reduction prescribed burning under mild weather conditions.
Finally, the authors advocate that the Precautionary Principle must apply: this means playing safe while the research is being done. The safe approach is not to ban prescribed burning because of an unsupported assertion that it may increase atmospheric CO2 levels, but to promote prescribed burning because it reduces the size and intensity of wildfires.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
I’ve not seen either of these ‘myths’ reported in the media. 6 million Jews were murdered in the holocaust and, as far as I know, no one has used that particular event as an analogy for a bushfire. Haven’t seen the prescribed burning = global warming = megafires one repeatedly produced in the media too. Perhaps I read the wrong publications. Could you provide links to these darstedly stories?
Nexus,
don’t you listen to the radio?
last Christmas it was ‘everywhere’ and on you ABC that the fires in north eastern Victoria were a consequence of global warming.
in California the fires are also going to get worst as a consequence of global warming …
and then just last week we had this
http://www.abc.net.au/news/stories/2008/07/09/2299136.htm … a national carbon trading scheme could give rise to calls for less prescribed burning
“1. Because of global warming, Australia will be increasingly subject to uncontrollable holocaust-like “megafires”; ”
It was repeated in the media because it was the result of a scientific study. So it is not a ‘myth’, but ‘reporting’. You won’t have to worry, however, in several decades the fires will have destroyed so much vegetation, there will be nothing left to burn.
Rather than attacking the media, perhaps you could address the findings of the scientists.
Severe bushfires linked to global warming
Tuesday, 9 December, 2003. Rafael Epstein
http://www.abc.net.au/pm/content/2003/s1006755.htm
There are growing fears that climate change will cause more damaging bushfires.
Last year, Victorian Emergency Services Commissioner Bruce Esplin said natural disasters were getting worse because of climate change. He pointed to the devastating 2006-07 summer bushfires in Victoria’s north-east…
http://www.theage.com.au/environment/less-land-ruined-by-bushfires-20080707-34ey.html
While Bush is attempting to score compassion points with the people of California, let’s tell him not to burn Californians by blocking their duly enacted laws. The EPA must allow the state’s Pavley, or “Clean Cars” fuel emission standards to go forward – along with the standards of a dozen other states that have followed California’s lead. No one fire can be blamed on global warming, but there is no doubt that changes in our climate are causing more fires that are more severe. The tragic events unfolding in California are yet another stark reminder that action is needed to combat global warming now, and the EPA should not stand in the way of California’s lead.
http://action.foe.org/content.jsp?content_KEY=3406
Well,
I can tell you of our success in the US.
The Native Americans (immigrants from Asia, perhaps) set the Central Great Plain afire annually, to help ensure that the plains did not get choked out by arboreal infestations.
These massive mid-continental fires completely failed to usher in the lush opportunities for herbivory which existed back when C02 was between 4k-5k ppm (about ten times what it is now).
These controlled burns *did* sustainably maintain the North American ecology.
Even today, we’ve maintained that heritage. Today, the continental USA absorbs more atmospheric carbon than it produces.
Other countries interested in our carbon production and sequestration successes are cordially invited to study our methods.
Although, it’s really pointless. We have 4,500 ppm to go before things get *really* tropical.
The report by Roger and his co authors confirms that Sustainable forest management in Australia includes fire as a key management element.
Our eucalypt forest is a fire evolved species and depends upon fire for regeneration.
Planned burning is an essential tool for forest management and is done for a number of key reasons:
• regeneration of eucalypt forest after harvesting
• risk management to protect forest assets and minimise fuel levels under controlled conditions in order that the risk of wildfire is reduced
• promote ecological diversity and specific plant species for conservation management.
However since 1990 the green movement has attacked this sustainable practice each Autumn, remember Flanagan’s “Nicotine Stain”. So it is pretty amazing that since we have been tracking greenhouse gas emissions, Tasmania has led the nation by reducing from 14.3 MT in 1990 to only 8.5 MT in 2006 a massive 40% decrease.
Faith tells us so much that can’t be verified by science. Who is God? Where does he/she live?
This blind faith is now determining attitudes that exscuse bad forest management for the past three decades. Leaves, twigs and branches fall to the forest floor and, because we don’t have a wet climate there is no mulching action. Fuel builds up without prescribed burning and summer’s lightning storms ignite the fuel and off we go.
This has nothing to do with the fallacious Global Warming and a lot to do with the greens insisting the forests are locked up and left alone.
Thanks Greens, you have now totally destroyed thousands of square – miles- of Victoria, S.A and N.S.W.
You want proof? Let me show you what the recent fires did to the bush around my back yard. Ring me on (03) 5143 1053 and we’ll make a date for an inspection.
Jennifer, thanks for posting this.
Clear and precise infornation is exactly what we need to ensure that management fires continue to be conducted.
Its no surprise that so often the wildest fires occur where the least control has been exercised in previous years.
The likelihood of course is that management of relevant types of forests with fire will release CO2, but equally obviously, that will happen in a controlled situation, unlike a wildfire that arises from no or poor fuel management where the likelihood is that far greater volumes of CO2 will be emitted.
Australia already has uncontrollable mega-fires. They burn in the scrub and forest between the Western Australian wheatbelt and the Goldfields.
You don’t hear about them because nobody lives there. They were reported this year, because unfortunately 3 truckers died as a fire swept across the main road east.
There is very little data on the size and frequency of these fires, but I happen to know that one in the 1990s burned for 2 years over 4 million acres.
I think anyone with hands-on experience of bushfire will know that Roger, Dave and Phil are telling the plain and simple truth.
A point they did not mention is that the more ignitions there are in an area of bush, the finer the vegetation mosaic will be, and the smaller the fires. Fewer ignitions on the other hand, lead, inevitably, to an unstable, coarser mosaic, and eventual bigger fires. There is a clear mathematical model of this, not yet published, but soon to be.
If diversity is the point at issue, then a finer grained vegetation mosaic is clearly more diverse than a coarser grained one. Animals have both shelter and feeding opportunities.
Further, a fine grained mosaic of small fires will not lead to water pollution by silt and ash, but a coarse grained mosaic of large, fierce fires will. The experiment has been done, both here (e.g. Brown 1972), and in South Africa (e.g. Scott 1993). There is a discussion (‘Burning issues for water supplies’) by S. Davidson (2004) in Ecos, Issue 120:8-12.
Glib dismissal of Aboriginal fire practice (e.g. Esplin et al 2003) is complete nonsense. As Deborah Bird Rose (1996) has put it, ‘There is so much to be learned from Aboriginal people – about land management with fire … Aboriginal burning practices are based on patch-burning with low intensity fires over a number of years to create a mosaic of habitats.’
If evidence from Australia is not enough, then anyone interested in the truth about fire should read Christian Kull’s (2006) ‘Isle of Fire: The Political Ecology of Landscape Burning in Madagascar’, or Oliver Rackam’s ‘Fire in the European Mediterranean Aridlands’ Newsletter No. 54 (available online). These are only a tiny fraction of the literature on the benefits of frequent burning.
Unfortunately,
At the recent Old Growth – New Management conference in Hobart, several international papers claimed that prolonged protection from fire would continue the sequestration of carbon and eventually produce peat and then coal. It may happen in other parts of the world and may have been the case in the distant past but in today’s Australian dry climate and high incidence of lightning, this is a pipe-dream. Fuel reduction is the only realistic option to regulate mega fires.
That’s Oliver Rackham, and delete ‘Unfortunately…’
From July 2008 issue of Australian Geographic, pp. 60 & 67:
“…media reports are always biased toward the populated south-east of the country. Elsewhere in Australia – such as in the desert or the savannah country – fires much larger than any of these are an annual event. “One at the moment is 60,000 sq. km – that’s a fire burning the size of Tasmania,” said Jeremy Russell-Smith of Bushfires NT late last year. “That’s not even reported in the local media, let alone the wider Australian media.”
later in the article:
“There’s no doubt that when people walked constantly over the landscape, burning as they went, the ‘patchwork’ of fire was intricate. Aerial photographs show that in 1953, in 2500 sq km of the western desert area, there were 864 measurable fire events, with an average burnt patch of 64 ha. Thirty years later there were just four measurable events, with an average are of 52,644 ha.”
If you burn rainforest or even the edges of rainforest you eventually convert it to dry forest.
This is what aboriginals did for their own good reasons. The more you burn, the more you have to and the more it will naturally happen, particularly in an aridifying continent like Aust.
I’m trying to regenerate old rainforests that have been burnt to the point where cliffs of basalt columns have collapsed as a result.
Only where these rainforests have been removed [probably always by fire] have the cliffs collapsed.
This is probably an evolutionary process and why we are such a flat continent.
My bushfire strategy is to have as cool a burn as seldom as possible.
Not only does wildfire remove flora but it leaves native wildlife very unprotected against our ever increasing feral predators and while we still have a good flora bank, our faunal bank balance is in dire straits.
This is much more important than our ACO2 balance.
Spanglo,
No doubt we should keep fire out of rainforests. The best way to do this is by burning frequently around them. In several parts of the world (India, Africa) frequent burning of surrounding grassland provides protection for ‘sacred groves’ of rainforest. In Africa there is ‘gallery forest’ along some rivers, which is like rainforest, with looping lianas, buttressed trees etc. It only survives when the neighboring grassland is burnt every few years. Keep fire out (an experiment was done) and the grassland is invaded by woody thornbush, which will eventually carry a much fiercer fire, which can punch right through the gallery forest, due to increased radiant heat. Look up the fate of the stinkwood groves of south Africa – the botanist Robert Brown admitted he probably destroyed them by banning frequent veld burning in the nineteenth century.
Don’t know whether this is an adaptation or incidental effect but some reckon the rock wallabies that live in the rainforest vine thickets emerging from the Undurra lava tube sinkholes actually prune the savanna grass back from the hole margins reducing fire risk. Are there any other incidences of this type of behaviour?
http://undara.com.au/lava-tubes/tunnels-to-a-wildlife-underworld/
Green Davey,
I suppose each bushland and savannah region has to be assesed depending on local specifics and dry forest trees need fire to propagate.
It’s a slow job to get rainforest to regenerate from a dry forest that has taken over through fire and in some cases not worth it because these days eucalypts are often more endangered than RF due to urbanisation.
However there is nothing more beautiful than RFs with good stands of big gums through them.
Luke,
I’ve noticed rock wallabies seem to have this passion for cropping grass to carpet level and just feeding on this carpet.
There’d be some interesting reasons for it, no doubt, if someone did a study.
In Chapter 1 of Garnaut’s review on Climate Change and the need for an ETS he states:
“In making their choices, Australians will have to decide whether and how much they value many aspects of the natural order and its social manifestations that have been part of their idea of their country. In the discussion of climate change, much is made of natural wonders—of the Great Barrier Reef, the wetlands of Kakadu, the karri forests. We know that we value them highly, and now we will need to think about whether we are prepared to pay for their preservation.”
Yet nowhere else in the 500 page report does he describe the impacts of climate Change on the Karri forests. Although he does refer to SW West Australia as a biodiversity hot spot, perhaps as defined by Norman Myer; to be a hotspot an area must contain at least 1,500 species of vascular plants as endemics, and it has to have lost at least 70 percent of its original habitat.
As Roger has some experience in Karri forests, is there any likelihood that the Karri forests needs all Australians to pay for its preservation?
Its perhaps worth time to read his previous post at http://www.jennifermarohasy.com/blog/archives/002326.html
Hands up those who have a degree in, and many years of, experience in forestry? For a Forest Scientist, university qualifications and experience are essential. If you dont have these qualifications, why make wide sweeping claims on extremely complex issues you obviously do not understand?
For too long the ancient art of forest management has been taken over by the feel goodies who haven’t a clue. It is disgusting and shameful.
We need to get our advice from the people who understand the immensity of the problems with forest management, those the green movement has ousted and denigrated, i.e the grand body of Scientists called Foresters. We must stop control of environmental matters being in the hands of the ignorant and raving ratbags in the greens.
Fires, their control and implications for the management of the land, have been part of the Forestry ethos and study for generations.
Why are we ignoring their professional advice?
During the winter of 2001 I travelled the top end – from Karumba in the gulf to Broome via the Gibb River rd. Everywhere we went were fires and the high flying kites that accompany them.
I was camping out in a 4WD van and every night we would have a fire. Collecting the best firewood was therefore a priority and we soon learnt that the best wood was from what we called the “Falldown Trees” These were baby eucalyptus that had reached a height of around 4m and had literally fallen over. Their interior had been white anted and the yearly burning had ring barked their trunks. They were everywhere.
From the gulf to the western coast had been burnt, not by lightning strikes but by man. An old miner outside Kununurra pointed to the hills around and said that now there were only a few trees on the hills yet when he first arrived 50 years ago they were covered in trees.
South of Broome was a bird sanctuary where the owner explained how 30 years ago there were huge flocks of birds which have since disappeared because birds need grass seed and when you burn it every year there’s no feed.
Sure the aboriginals used to burn but a small nomadic tribe on foot with a fire stick is a totally different story to 5 of them in a Landcruiser Troupe with diesel guns which is what we witnessed day upon day.
We eventually camped by the Margaret River near Fitzroy Crossing – suddenly we were we surrounded by fully grown magnificent “falldown trees”. We could hear the wildlife that accompanied them, birds, reptiles and roos thumping in the night. The only wildlife we experienced during the 5 month trip. The next day the station owner admitted that the area hadn’t been burnt, it was their private camping ground.
The yearly burning of the top end is a serious environmental disaster facing this country yet no one seems to be concerned.
So perhaps we have two Australia’s – the north which is burnt too often with hot fires and the south which isn’t burnt enough, resulting in episodic conflagrations. ?
My partner on the trip did hear a report on RN of similar trees appearing in the Blue Mountains – i.e. ringbarked by fire and falling over – they even referred to them as “fall down trees”
Prescribed burning is the only tool that we have to effectively manage the amount of fuel on land that is not under the plow.
You have to decide to what end result you want from your management of that land.
Is it to protect assets on the bush urban interface or is it to protect a high value ecological regime?
All I know is that having attended a poa tussock fire last night in a bush paddock with an air temperature of 3c and a frost on the way, it was a lot better now than in the middle of summer with a temp of 30 plus degrees and a howling westerly. The fire was part of a management plan to protect assets but got away with a gust of wind. The unplanned can always happen and was a lot easier to deal with in the middle of winter than in the middle of summer.
There are a lot of inputs into the decision making process but there are two constants.
The bush WILL burn (even without human intervention) and it WILL grow back, given time.
As someone who was a forester many occupational reincarnations ago, the notion of small localised fires lit by aborigines in our pre-european history puzzles me. I tried on a couple of occasions to light small localised fires in mild conditions and believe me they did not always stay small and localised. The only research I have heard of in this context was with button grass plains in Tasmania. I can accept that fires there could be small and localised. But I wonder whether this finding has been generalised across Australia by idealists. What seems more likely to me is that aborigines were no more successful in containing their fires than we are. Their presumed goal was in producing grassland, so the frequency and intensity of their fires woud have been geared to this. Note a few bits of circumstantial historical evidence: cook noted many (large) fires clearly visible fom out to sea; the land was likened to South Wales (pastureland with copses and small woods?); european settlers took their flocks to vast pre-existing pastures that stretched away from Sydney. Does anyone know of any research or have insight into this question?
Bernie,
There is plenty of history, and practical experience, which shows that trying to burn small patches in the midst of a sea of long unburnt is mission impossible. However, patches of long unburnt in an ocean of frequently burnt are entirely possible, and are well known in many parts of the world. Hence rainforest patches for example.
Western Australia’s first Conservator of Forests (1916), Charles Lane-Poole, was European trained, hated fire, and tried the former strategy in the jarrah forest. Predictably it failed, and, combined with logging trash, caused eventual fierce, destructive fires.
His successor, Stephen Kessell, also tried burning only small patches (5 chain breaks around timber blocks). The fires got away, and he faced a mutiny by forest workers, who knew what they were talking about. He finally admitted that the only way was broadscale, frequent, mild fire, set by people who knew local conditions.
Luke,
There is extensive literature on interactions between grazing and burning. As a start, Booysen and Tainton (1984) Ecological effects of fire in S. African ecosystems. More recently, and locally, Murphy and Bowman (2007) The interdependence of fire, grass, kangaroos and Australian Aborigines. J. Biogeography 34:237-250.
Then there is, of course, old Sir Tom Mitchell, back in 1848. “Fire, grass, kangaroos, and human inhabitants, seem all dependent on each other for existence in Australia …”.
Thanks Davey
Large areas of eastern Australia are also changing to greater woody dominance from reductions in fire frequency. Areas have “natural” trees that weren’t there 50 years ago. “Woodland thickening”.
A carbon sink of magnitude but also a subtle form of land degradation.
http://www.ingentaconnect.com/content/bsc/gcb/2002/00000008/00000008/art00006
More documented changes due to fire:
http://www.aph.gov.au/HOUSE/committee/JSCT/kyoto/sub38attach4.pdf
Thanks Moha – er – Luke.
Ah so you still think I was Moha eh? Nope. Swear on a stack of IPCC reports.
4 DOWN (8) Nah, just a silly mixed up mad homme.
Apologies: Watching the Tour de France in daylight takes precedence over blog-front politics, sorry.
On this bike race rest day I read the thread comments first as I usually do then looked up some books in my library with the sole intention of offering a bit more from my narrative in response to Dave and one or two others but I decided to read the report via the link.
1) I don’t like the term “prescribed” burning as used in the front page. In fact I have never gone along this path. Every area in every region has different peculiarities
2) The idea that some elitist central body can manage our environment with their “prescribed” fire is nonsense in that it defeats the concept of fine mosaics from the outset. Each one of us sees a different picture. We need to get right back to what individuals can do with their patch given a full opportunity.
3) We are still only paying lip service to local knowledge and tradition. The prescribed burn in wandoo forest, Western Australia as pictured is hardly typical of conditions most land managers face in rugged country anywhere today. That’s where our trouble starts.
4) Any rigid intreprentation of the recipe can’t allow for the other complexities and expectations. Too often modern fuel reduction campaigns are run by single interest groups.
5) “there will only be an increase in average annual temperatures of between 2 and 4 degrees over the next 100 years. The effect of this on bushfire behaviour, by itself, will be trivial” This bit is regretable. As I have said often enough here, “climate change” is not only about average temperature change.
Let’s get back to studies and “evidence”. There is a creeping tendency to view all old growth as potential rot. New growth versus old growth is all about forest harvest rates IMO. Natural forest in Tasmania although widely varied was incredibly dense at every stage of its development. Old trees and their timber survived hundreds of years even in death. Wild forests featured massive standing dead trees and the forest floor was littered with ancient logs. Carbon stored above ground averaged meters deep.
A lot of practical history is lost however some of us old timers with long roots know how to recover it. The character of the bush as it was is still there in paintings, photos and stories. I can relate to the original track cutters too.
A practical knowledge of track building before and after fires helps with early photos and paintings. I can say a lot of this once forest rich country was hardly ever burnt in your average human life time.
Gavin,
I agree with you on the importance of local fire knowledge. I think several bushfire enquiries, from Stretton (1939) onward, have stressed this aspect, yet not much has been done, as far as I know.
Perhaps it runs against the centralizing tendency of ‘big fire business’. The most recent Victorian Government bushfire report (2008) does give local knowledge more emphasis. Will it happen?
In defence of Roger’s photo of mild burning in wandoo, I agree it is only one vegetation type, but it would be rather impractical to try showing photos of such fires in all the vegetation types of Australia. I know that such mild fires are possible in jarrah forest too, provided patches are burnt as soon as they will carry a fire. For jarrah, this is every 2-4 years. Exclude fire for only a few years, and ‘giant fuel patches’ will form, setting the scene for giant fires. A longer fire season in southern Australia, due to climate change (if it happens as predicted), can only make ignitions more likely. Perhaps they will become so frequent and widespread that a de facto ‘prescribed burning’ regime will establish itself. There are self-organizing tendencies in nature, although they may not always meet with everybody’s approval.
There is sound mathematical theory to back the ‘giant fuel patch’ idea, but I need to publish it first. Past experience in academia tells me that it is unwise to reveal your ideas too fully before publication. Knowing academic hunger for publication, perhaps I have, unwisely, said too much already. Shut up, Davey…
P.S. The latest Victorian Bushfire Report (2008) is available online.
Dave: One book can’t cover the complexities but many free hands with a fire stick certainly can however IMO we have lost that practice at the grass roots.
I recall a comment up the thread about the difficulties for individuals trying to get back into it on their own. Fear of community reactions must be a big deterrent now.
There is another point about fire frequency from deliberate lighting attempts of one kind or another. Bushland near towns becomes a special case with increased weed infestation over time. This changing fire regime is what concerns me most when considering wild fires in mixed dry vegetation can travel with the wind speed on the day. Local communities must do routine maintenance on a broad front one way or another.
Our National Parks on the other hand tend to be proclaimed in more remote regions that have little or no agricultural value. Bushland on poor soils is another special case. We can’t overdo the maintenance to the point that it reduces diversity. What carries fire best is a withering crop. If farmers can use that principle to reduce weed seed loads, so can other land managers.
This brings me to think about button grass again. These waterlogged tussocky acid soil regions in Tasmania go down to the sea but are more like alpine areas elsewhere as they don’t have thick bush to consider. Once dried; they burn through the peat for months and flare up again through any scrub on the sea breeze.
“Thick bush” btw is where one carries an axe with the fishing rod to chop every log in order to find your way back if need be.
Scrub bashing is another phase of wilderness experience and that’s much worse after repeated fires because there are no logs to chop and plenty blackened spears to avoid.
Gavin,
Dr Jonathon Marsden-Smedley, and others, have done some useful work on fire in Tasmanian button-grass. Check out Google Scholar.
I think the general finding is that Aborigines burnt the button-grass every few years, so preventing fuel accumulation, which would carry hotter fires up into the eucalypts and, eventually, the rain-forest. Makes sense to me, but not, perhaps to those with ideological views on bushfire as an unmitigated evil.
If I remember correctly, other modelling by CSIRO showed that frequent burning, even in a patchy way (about a third of the area each year?), would prevent major bushfires making a run.
Dave; you can write a book if you wish without doing some field work here and there but it’s going to be based on guesses about what actually went on before white man entered the oz scene.
I doubt very much that aborigines bothered to protect eucalypts or rainforest by frequent burn offs at the margins in Tasmania. Given most of the landscape was heavily wooded they had to suppress scrubby regrowth to get access to virtually all land above sea level. Rain forest on the other hand would be quite passable at ground level except on steep terrain. Hint; they ate a lot of shellfish after cooking them just above the waterline. Early settlers on the other hand had a bad time tripping round the edges of these wild places. Every yard of beach above the shoreline was covered in massive piles of forest debris particularly on the West Coast.
We know about the exceptions like the drier Midlands region from John Glover’s paintings (early 1800’s) which show open woods through that country but these pictures too feature lots of fallen tree trunks. Anyone with access to Glover’s works should spend a few moments looking for tell tale stumps and wholesale clearing for grazing. I guess much of Victoria would have been the same as new settlers came in.
Another view comes from our mining history. During the 1800’s the rain forest on the West Coast of Tasmania was badly damaged by exploration and mining activity. Timber cutting was only one aspect. Repeated fires removed the original forest and prevented tall timber regrowth like no other human enterprise. Heavy rains removed remaining fertility.
This is well captured in J W Beattie’s late 1800’s photographic collection. Beattie covered the mountains along the rail routes from Mt Dundas to Kelly Basin. Linda Valley shows typical bushfire destruction.
Dave; I’m sure research in all states begins with similar archives. Over zealous and careless use of fire in the bush can be avoided only if we know how it got to be in the first place. Recreating those conditions after a series of major impacts including land use and climate change will be difficult enough given our short history in the practice.
Good luck.
Gavin,
Since you live in the Apple Isle I won’t argue with you. I was pointing out Jon Marsden-Smedley’s work. I do know something about the jarrah forest, having worked and walked there for forty years. I think we can agree that, with bushfire, hands-on local knowledge is essential.
Gavin,
Since you live in the Apple Isle I won’t argue with you. I was pointing out Jon Marsden-Smedley’s work. Local knowledge of bushfire is essential, and the most recent report from the Victorian Government supports this.
After forty years of working and walking in the jarrah forest, I do feel qualified to talk on bushfire there. It needs burning every 2-4 years, as it was by a combination of lightning and Nyoongar folk up to the First World War.
Sorry, thought the first one didn’t work.
Dave: I’m sure we don’t have to formalise the indigenous bush practice in some scientific way in order to understand it. IMO it remains along with all nature essentially random. I’m opposed to a rigid regime that claims to know all too.
Considering ancient landscape management with fire, we could say it was crafty but do we need go further? Manmade ignitions often go wild. That’s fortunate if it does the hazard reduction job well but more likely someone regrets the destruction at the time.
Outcomes remain anybody’s guess with and without bushfire models.
We are no better in dealing with AGW hey. BTW I now live in the ACT.
I love the one where the forest gets so old it dies and rots releasing all the Carbon therein.
Can someone give an exmple of such a forest.
National parks have existed for over 100 years and you would think that as they started with some mature forest in them there would by now be examples of this phenomenon in the modern times.
Of course there could be a reference in the literature of the ancients as they came to unpeopled forests, if such things existed.
And then there is that dastardly release of Carbon.
It must be held in a special place as the MBAC Report for Forests Tasmania [it was on their syte] quantifies the per ha rate of Carbon accumulation in the informal and other reserve forest managed by them at 6.59t CO2 per ha per annum in the 2010-2020 period and continues to give an accumulation rate out to 2050.
Perhaps the mass hides this process along with all the otrher paranoia.
I await the example of a living system failing due to the coincidence of the aging process of all its parts and the failure if the systems of decay.
In reality, if anyone could be bothered to project the changes in temperature and rainfall onto an extant system they will find if those are exceeded in either direction the forest, or indeed any other vegetation system, will collapse just as the Sahara Forest continues to do today, albeit also under much greater human pressure now.
Such a change in the basic environmental parameters will see the Carbon in the atmosphere grow massively as the one of 2 natural sinks fail. The ocean will fail shortly thereafter, swamped by C and thus acidified.
Ashes and tears are very likely to be on the cards. The significant changes aere there for those who look.
Hello Madam jennifer you are no doubt vast in the area of Bush Fire issues, Please can you accept to come and present a paper in our Up coming workshop on bushfire to hold on 17th-18th Sept in Nigeria for more log unto http://www.bushfireworkshop.org