Does fuel reduction burning help prevent damage from fires?

As the fires that started in Tasmania in early January continue to burn, a rising flow of letters to the editor, radio raves and internet utterances are questioning whether the state and local governments in Tasmania have done enough to reduce fuel in the forest. People urge lifting legal restrictions…

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There has been an outcry in Tasmania against legal restrictions on fuel reduction. AAP Image/Twitter Botonaine

As the fires that started in Tasmania in early January continue to burn, a rising flow of letters to the editor, radio raves and internet utterances are questioning whether the state and local governments in Tasmania have done enough to reduce fuel in the forest.

People urge lifting legal restrictions on fuel reduction related to threatened species and vegetation conservation. They want money spent on nature conservation programs, like fox control, be diverted to control burning the bush. They blame the Greens for everything. Some hark back to the days when hardy, practical Tasmanians were able to burn the bush at will in their traditional ways.

What is our scientific knowledge of these issues? Are the Tasmanian governments managing the bushfire risk appropriately?

February 7 1967 was a day of comparable severity to January 4 2013. Both days hovered between extreme and catastrophic on the current fire danger scale. Most of southeastern Tasmania burned on February 7, more than 100 human lives were lost and thousands of buildings were reduced to corrugated iron leaning on a brick chimney. On January 4 2013, no lives appear to have been lost, the fires have covered only a small part of the southeast and about 170 buildings have been incinerated.

The major reason for this spectacular difference in outcomes is the small number of fires that were alight or were ignited on January 4 2013, compared to the extremely large number on 7 February 1967. Back then, the response of some people to a bad fire day was to light up surrounding bush to protect their properties.

In 1967 fire was seen as a tool for use by everyone on the land. For instance, fire was widely used to eliminate unpalatable growth on grazing properties. Today, most graziers do not use fire, because of the legal and social difficulties associated with ignition. The lack of fire on these grazing properties has caused a thickening of the tree layer and higher levels of fuel on the ground. In some places, short grasslands that do not readily burn have been replaced by highly flammable shrubs. Many nature conservation values have suffered a decline.

In 2013 most of the Tasmanian population has been convinced by weight of argument, experience and legal coercion that burning the bush is too risky an activity not to be left to professionals. This change in social attitudes has resulted in a dramatic drop in fire frequency in dry eucalypt forests, the ones most likely to burn.

The main reason for the lack of human mortality on January 4 2013, compared to other catastrophic fire days, is the emergency response activity of state government agencies. They have developed integrated emergency response plans that involve all government and volunteer organisations, and have deluged the local populace with information on how to prepare for fires and what to do when a fire occurs.

Fuel levels in the bush are very much a minor issue in mitigating property damage and human mortality from vegetation fires. An analysis of property loss in the catastrophic 2009 Victorian bushfires showed that there was no difference between being adjacent to state forest and being adjacent to a national park, despite the higher level of fuel control in the former.

The best predictor of loss was the vegetation within the vicinity of the house. Having no woody growth (presumably a surrogate for no ground fuel) meant a better chance of having a house after a fire.

It has become abundantly clear that fire protection of property relates largely to what happens immediately around a property and the minimisation of opportunities for spark ingress to the buildings themselves. There is also a substantial random component in property survival that motivates fleeing in extreme and catastrophic conditions. In extreme and catastrophic fire weather, the front burns through or leaps fire breaks, apparently bare paddocks, salt water inlets, rivers and any other obstacles to its progress, with spot fires up to 20km ahead of the main set of flames.

In less than extreme fire weather, areas of fuel-reduced bush will act as safe places for back burning and may act as barriers to spread. However, if nothing else is done, large areas need to be planned burned to lower the probabilities of losing fire-susceptible assets.

Karen King and her associates modelled the areas that needed to be burned in western Tasmania to reduce losses of fire-susceptible rainforest and alpine vegetation. Burning less than 10% of the area of buttongrass moorlands per year had virtually no effect.

In southeastern Tasmania and elsewhere, it is not possible to safely control burn the widespread wet eucalypt forests. On extreme and catastrophic fire days, fires will burn through recently fuel-reduced dry forests and apparently bare paddocks to burn explosively in these wet forests.

Tasmanian government agencies responsible for fire management are well aware of the above realities. They see fuel reduction as desirable in some situations, while being only a small part of the process of preventing and mitigating fire disasters. In both planning and implementing fuel management and fighting fires, the Parks and Wildlife Service, Forestry Tasmania and the Tasmanian Fire Service work well together to achieve the outcomes they can within the budgets they are given.

In response to the fire at Scamander in northeastern Tasmania in 2007 and the inquiry into the Victorian 2009 fires, the Green ministers convinced the Tasmanian State Government to increase funding for planned burning. This not only has the minor importance in fire disaster prevention described above, but is also useful for maintaining timber values by preventing crown fires, and for maintaining populations of the many native species that suffer from a lack of fire regimes suited to their life cycles.

We need much more planned burning for ecological purposes. We probably do not need much more for fire disaster prevention and mitigation. However, burning the bush after fire disasters has been a time-honoured way for Australians to cope emotionally with their powerlessness in the face of extreme natural events, so we are highly likely to see more of it.

Perhaps it can be done where it is needed for nature conservation. The letter writers and tweeters are unlikely to notice.

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34 Comments sorted by

  1. John Newlands

    tree changer

    I think successful litigation could entirely change the perspective on burnoffs, with several types of complainants
    1) someone requiring expensive respiratory help
    2) loss of property in a fire gone out of control
    3) cancellation of carbon credits e.g. under the CFI program.

    I seem to recall Bushfires NT recently admitting they caused a fire that damaged a site near Yuendumu. A couple of years ago a historic hut in Tasmania the 'Adamsfield Hilton' was destroyed. The parks service blamed it on lightning but by coincidence a burnoff was scheduled for the same day.

    So far the fire lighters have got off scot free since they represent officialdom. If that changes perhaps it will become more professional and involve helicopters and backup crews.

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    1. Mark Poynter

      Forester

      In reply to John Newlands

      John

      Since there is a considerable body of science and operational case studies supporting the notion that fuel reduction burning does in fact reduce the damage from bushfires, there is probably also the prospect of litigation by those burnt-out by bushfires suing fire agencies for failing to do enough to minimise fire impacts.

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    2. Aaron Troy Small

      Student

      In reply to John Newlands

      Some of the worst instances of preventative burning by officialdom have involved firelighting by dropping incendiary devices from helicopters on the wrong side of rivers.

      I take it you are categorically opposed to preventative burning for any reason. Go take a look at the country destroyed by the recent wildfires, there isn't some degradation of habitat in a defined area, there is absolute destruction of habitat for thousands of hectares, with the associated destruction of entire ecosystems.

      Funny thing really, I've never seen any of the people who protest against planned hazard reduction burns choose to chain themselves to the trees in front of an actual bushfire. Why is that?

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    3. Robert Tony Brklje

      retired

      In reply to Mark Poynter

      However the flip side of fuel reduction burn off, is the promotion of species that gain evolutionary advantage from bush fires and the further elimination of species that are disadvantaged by bush fires.
      The Australian natural landscape is not natural, it represents tens of thousands of years of fire stick farming, harmful or beneficial.
      Whilst fire stick farming supported the nomadic lifestyle of humans at that time, in clearing landscape and making hunting easier, how truly destructive was, how…

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    4. Mark Poynter

      Forester

      In reply to Robert Tony Brklje

      Robert Tony Brklje

      The centrepoint of your argument is about what constitutes 'natural'. I would think that most people would think that the natural state is that of 1788 despite it being partially shaped by human burning over tens of thousands of years.

      The weakness of your arguement is the presumption that pre-European fire is all attributable to humans, when much if not most has always been due to natural causes ie. lightning. So no matter how we might like to re-construct Australia's native vegetation, it will always have to co-exist with fire, which it is adapted to do.

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    5. Bernie Masters

      environmental consultant at FIA Technology Pty Ltd, B K Masters and Associates

      In reply to Mark Poynter

      Mark, I hate disagreeing with you but, for much of the pre-1788 inhabited landscape of Australia, lightning was probably the lesser cause of fires when compared with Aboriginal burning. Lightning was still common and a significant ignition source, of course, but the records of early explorers and settlers clearly show that most fires were started by Aboriginal people and it can therefore be quite reasonably concluded that many lightning-started fires stopped when they reached low fuel areas that…

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    6. Mark Poynter

      Forester

      In reply to Bernie Masters

      G'day Bernie

      I suspect the respective extent of the roles played by Aboriginal and natural (lightning induced) burning probably varies around the country.

      In Australia's north and centre, you may well be right about the greater preponderence of Aboriginal burning. In the south, particularly in the forested ranges where Aboriginals are thought to have rarely ventured, lightning may well have been greater cause. The debate about FRB is centred on these southern and eastern ranges and their forests.

      A recent book by Hately (2010) about the evolution of Victoria's vegetation drew upon observations by early explorers and settlers to conclude that most Aboriginal burning was limited to coastal areas and valley floor open woodlands, rather than the upland forests of the ranges.

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    7. Bernie Masters

      environmental consultant at FIA Technology Pty Ltd, B K Masters and Associates

      In reply to Mark Poynter

      Hi, Mark. I agree that Aboriginal fire regimes around Australia varied enormously depending upon the resources they obtained from different ecosystems and different parts of those ecosystems. For example, the jarrah forest in WA is mapped as a large broad belt of country running from north east of Perth southwards to the south coast. In fact, such mapping ignores the many different vegetation types found within this forest type. In turn, available evidence suggests that Aboriginal people generally…

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  2. peter prewett

    retired

    One thing that never gets mentioned is the loss of wild life.

    Or how long, if ever, does it take to return.

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  3. Mark Poynter

    Forester

    It is disappointing that discussion about the value of fuel reduction burning following major bushfire events always centres on house loss as a measure of its value, and is principally used to deflect criticism of environmentalism which has typically obstructed the widespread use of the practice.

    In many ways this is a 'straw man' arguement because formal proponents of prescribed burning have never claimed that it totally prevents the loss of lives and properties and have acknowledged that under…

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    1. Jack Arnold

      Director

      In reply to Mark Poynter

      Thank you Mark for your professional insights.

      Controlled burns along road verges at least, and preferably, to a width of 50 metres, doing each side in alternate years, may be a useful preventative or containment measure, provided the onerous government restrictions about timing & burn conditions are relaxed.

      But then, as John Newlands (above) notes, governments are keen to restrict damages claims from plaintiffs who rely upon the failure of government to act appropriately in an emergency situation.

      Prevention is always better and cheaper than a cure.

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    2. Aaron Troy Small

      Student

      In reply to Jack Arnold

      Keeping road edges/verges mowed and cleared should reduce the chance of ignition and then both flame heights and fire intensity if they start (Baxter 2008 <http://wildfire.fpinnovations.ca/67/AD_10_3.pdf>;; cf Cheney et al 1993 <http://www.publish.csiro.au/paper/WF9930031.htm>; & 1998 <http://www.publish.csiro.au/paper/WF9980001.htm>;). I've just downloaded the Kindle edition of Cheney & Sullivan, "Grassfires: Fuel, Weather and Behavior" (2nd Ed), so I'll have to check on that. But it seems intuitive that if the fuel height and load is reduced, then fire intensity and spread should be similarly reduced.

      PS Be bloody careful if you decide to slash/mow at present, the fine fuel (ie. grass) is fully cured and if you give it a spark it will go like I don't know what.

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  4. Aaron Troy Small

    Student

    The most dangerous component of wildfires/bushfires in Tasmania appears to be when the fire "spots" ahead of itself, from one hilltop to the next, with the spots falling into heavily overgrown, dried understorey's, leading to the rapid development of "crowning" and ember attack of the next hilltop. It was the major feature of the Inala Rd, Forcett fire on day one (3 January 2013).

    I cannot help but thinking that if hazard reduction burns had been done on the hilltops (and the area immediately…

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  5. Keith Thomas

    Retired

    Controlled burning is a clumsy, ignorant way of reducing the fire risk from forest litter.

    We need to ask why fuel accumulates to such an extent today when it can not have been so great in the previous thousands of years. If it had been, there would be very different forests as firestorms kill most trees, whereas less-intense fires do not. The fact is that pre-Europeans, the natural microbial decay processes were much more intense and uninterrupted than they are today, and forest litter broke…

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    1. Jack Arnold

      Director

      In reply to Keith Thomas

      You have an interesting suggestion here, Keith.

      This sounds like a sensible alternative requiring scientific testing, especially with the E nitans link to cancer hotspots.

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    2. Michael Shand

      Michael Shand is a Friend of The Conversation.

      Software Tester

      In reply to Keith Thomas

      Great Comment, I have the same feeling, whilst reducing fuel load does mitigate fire risk - it doesnt have to be burning

      I feel the burning approach, whilst being the best we have at the moment, is far too short sighted and unsustainable - like with climate change creating hotter and drier summers, if we dont look for alternatives we are going to be levelling and burning the entire bush in the future - there is no fuel load in a desert or massive car park after all and unless we can come up with better management strategies I fear this is where we will end up

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    3. Jodie Lia

      Ecologist

      In reply to Keith Thomas

      I agree. SOME controlled burning is required (particularly for ecological reasons) But, IF the ultimate goal is to protect life and property (which is the concern of many) then I think the focus needs to shift from increasing fuel reduction burning in forests to increasing fuel reduction around properties. And this is the responsiblity of the property owner! The best way to protect a home is to have a cleared Asset Protection Zone in the immediate vicinity of the dwelling.
      You have to consider…

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    4. Michael Shand

      Michael Shand is a Friend of The Conversation.

      Software Tester

      In reply to Jodie Lia

      Im not that interested in saving properties - I mean if thats the goal then why not build a massive carpark right around all communities - this is what your suggesting yeah? just a massive desert area around all houses and communities?

      Focusing on protecting property alone is short sighted, self centered and of little interest to me - we already know how to protect your home - sprinklers, fuel load reduction, etc - all the things you said, thats not really of great concern to me compared to protecting the bush

      hint, the bush burning down every year is not sustainable - the bush will eventually die off

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    5. Jodie Lia

      Ecologist

      In reply to Michael Shand

      Ok strawman. Yeah that's exactly what I was suggesting, a massive carpark/desert around houses and communties.
      Note how it's called fuel REDUCTION, not fuel obliteration??

      I doubt that people living in rural or bushland communities would care for your interest in letting their houses burn down either.

      I am suprised that you haven't worked out the link between property loss and burning of the bush - The protection of human life (and property) will almost always trump protecting the environment…

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    6. Aaron Troy Small

      Student

      In reply to Keith Thomas

      I agree to a point, there ought to be a better way, but having been up more "supposed" fire trails and tracks in the last couple of weeks I wonder how much thought you have given to the difficulties of access and who is going to pay for this? There is also the problem of erosion and other difficulties associated with increasing the number and upkeep of the extra tracks through native forests, and the felling of much, much more than the odd obstructing tree.

      Unfortunately fire is the most cost…

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    7. Jodie Lia

      Ecologist

      In reply to Aaron Troy Small

      With regards to it being the most cost effective method - controlled burning is a relatively short term option to manage hazard generally only providing 2-4 years before fuel loads have substantially increased to a level where they provide little effective hazard reduction. Controlled burning operations are also highly restricted by the availability of a suitable fire trail network maintained to the appropriate standard (as you mentioned) and appropriate weather conditions and fuel moisture.
      Manual fuel reduction around homes and at the urban/bushland interface has greater initial outlay but low maintenance costs that can be done in any weather (and I am not talking about clearfelling 50m fuel breaks. Selective removal of the understorey and thinning of trees is usually sufficient). This then provides increased property protection allowing the focus of burning to be ecologically based.

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    8. Michael Shand

      Michael Shand is a Friend of The Conversation.

      Software Tester

      In reply to Jodie Lia

      Yes, I know its called Fuel Reduction - but what you call fuel for fire is also known as food for the soil and what you end up with is slowely making the land harder, less fertile, less usuable over time - this wouldnt usually be a problem but now that climate change is upon us the bush is going to become increasingly combustable

      We already know how to protect peoples homes, its all over the place, repeating this information here isnt news, its not interesting and if people are ignoring this - then I dont know what to tell you - to me its like when the wall st brokers loose big and cry "But this affects me so nows its important".....what did you expect? eventually you knew something like this would happen - why didnt you prepare, I can empathise with you but I have little to no sympathy

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    9. Jodie Lia

      Ecologist

      In reply to Michael Shand

      I am an ecologist, I work in bushland and bushfire management and personally care a lot about the environment and its inhabitants - hence my environmental qualifications and pursuit to protect it in my chosen field. I care more about managing natural ecosystems for their health than to protect ignorant people who live near the bush but dont care to appreciate both the beauty and risk of doing so.
      I detect your sentiment but you are not really making sense in your argument. On one hand you are advocating…

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    10. Michael Shand

      Michael Shand is a Friend of The Conversation.

      Software Tester

      In reply to Jodie Lia

      Fair point, I should probably add that I am encouraged that there are people like you who are fighting the good fight and trying to help people on the ground where it really matters. I realise that we may have been cross-talking, that is talking about related by slightly different subjects.

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  6. Bernie Masters

    environmental consultant at FIA Technology Pty Ltd, B K Masters and Associates

    The author is misquoting the report "Land Management Practices Associated with House Loss in Wildfires" when he says: "Fuel levels in the bush are very much a minor issue in mitigating property damage and human mortality from vegetation fires. An analysis of property loss in the catastrophic 2009 Victorian bushfires showed that there was no difference between being adjacent to state forest and being adjacent to a national park, despite the higher level of fuel control in the former."
    The report…

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    1. Jane Rawson

      Editor, Energy & Environment at The Conversation

      In reply to Bernie Masters

      Hi Bernie, Professor Kirkpatrick is having trouble logging in so he asked me to leave this reply to your comment:

      It is impossible to report everything in a short article. The relationship cited by Bernie Masters reinforces the point that what matters most in dire conditions is the fuel in the general vicinity of the asset, rather than out in the bush.

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    2. Mark Poynter

      Forester

      In reply to Jane Rawson

      Jane / Professor Kirkpatrick

      No-one doubts the importance of fuel in close proximity to the assett, but focussing on this to somewhat dismiss the value of broader-scale FRB is to ignore the reality that in 95% of bushfires it enhances control efforts and can stop the fire from ever coming close to threatening houses/assetts.

      The focus on house loss under extreme conditions is also somewhat of a straw-man argument anyway, because those who advocate FRB have never said that it will prevent bushfires or house loss, but that it can reduce it. And as I pointed out in an earlier post, there is now modelling to prove it.

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  7. Bernie Masters

    environmental consultant at FIA Technology Pty Ltd, B K Masters and Associates

    Reading the various comments, it dawned on me that, in fact, the author of the article and most people making comments (including myself) miss an absolutely crucial point, namely, that most of Australia was subject to Indigenous fire regimes for 50,000 years prior to European settlement. For modern-day ecologists and land managers to ignore the implications of what Sylvia Hallam first pointed out in her 1975 Fire and hearth book and last year in Bill Gammage's The Biggest Estate on Earth book shows…

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    1. Nonie Jekabsons

      Tree Spotter

      In reply to Bernie Masters

      The co evolution of flora, fauna and humans in Australia over the last 40,000 - 60,000 years has resulted in a selection process that favours ecologies that are fire resilient and sometimes fire dependent. This is not an ideal situation - not ideal in terms of sustainability, biodiversity or climate stability. The use of fire as a tool by humans, while serving the humans well in many ways, has led to an overall reduction in abundance, soil fertility and resilience of ecosystems, and is continuing to do so. A biodiversity which is the result of fragmentation is a delicate one. Yes, we can learn much from the past and the selective, considered application of fire can be part of a solution, but ultimately ecological communities, including humans, that improve soil fertility, increase rainfall via evapotranspiration, discourage erosion and do not require fire to thrive must become the goal if we are to be truly sustainable.

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    2. Bernie Masters

      environmental consultant at FIA Technology Pty Ltd, B K Masters and Associates

      In reply to Nonie Jekabsons

      Nonie, I understand the points you're making and agree with you to some degree but in response I make two comments. First, the evidence from south west WA is that only a portion - 25 to 50% - of the landscape was regularly burnt by Aboriginal people. The remainder was burnt by infrequent, hot, large, lightning-started fires and, in these areas, I assume your concerns would not apply. Second, even though Aboriginal fire is not ideal, the alternative is for us to play God and assume that modern people…

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  8. Tony Kennedy

    Teacher

    Fuel Reduction Burning (FRB) is currently a prescribed management technique for fire prone areas of Australia. Whilst it may be effective in the short-term, can it really be a sustainable practice and if it is used on a continual basis will it really reduce the frequency and intensity of ‘bush’ fires?
    Australian flora and fauna have evolved to use fire as a tool for renewal. Many Australian plants need fire in order for their seed capsules to open and to enable their seeds to be dispersed. Many…

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    1. Mark Poynter

      Forester

      In reply to Tony Kennedy

      Tony

      I think you've partially answered your own question. Frequent low intensity fire is a natural process to which the bush is adapted and therefore if burning programs are established to replicate the natural burning frequency, then it must be sustainable I would have thought.

      Most of the fear that surrounds FRB is based on unrealistic expectations of its use in terms of extent and frequency that are neither desirable nor logistically achievable by land management agencies. So, unfortunately it will probably never be able to used to the extent that would be needed to fully replicate the natural pre-European state, whereas you are articulating unwarranted fears that its use will exceed what is natural.

      As for rainforests, in southern Australia at least (and presumably elsewhere), the wet eucalypt forests which precede rainforest development are too wet and too sensitive to fire, and so are not actually subjected to fuel reduction burns.

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    2. Tony Kennedy

      Teacher

      In reply to Mark Poynter

      Mark, you have missed my point.
      As a forester, of course fuel reduction burning would be considered beneficial.
      However, from a horticultural / environmental / soil science perspective, then fuel reduction burning is not beneficial as it changes the forest type to that that is more prone to burning and the regimens of fire, whether natural or man-made.
      By not doing FRB the organic content in soil increases, hence forests become more moist, and this leads to them becoming more like the wet scherophyll forest and then the rainforest type.
      If fires are continually lit then Australia will become continue to become a dry environment. FRB promotes the growth of dry sclerophyll forest which is the type that requires frequent burning.
      Mark, as you correctly stated for rainforests in southern Australia and the wet eucalypt forests that precede them are too wet to be subjected to fuel reduction burning.
      Cheers,
      TK (Horticultural Scientist)

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    3. Jack Arnold

      Director

      In reply to Mark Poynter

      Uhm ... small correction here, Mark. Rainforest is usually REPLACED BY WSF because the RF species grower slower than WSF Eucalypts and require higher humidity for longer periods while germinating and seedlings. The Arrawarra Rainforest successfully discouraged a fire raging in the surrounding grassland because the high humidity air trapped under the canopy basically dampened down the fire front when the brush surrounding the rainforest was breached/consumed by the fire.

      Thank you all for a well resourced discussion.

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