What is the science behind increased hazard reduction burns?

[Moondog55]

Actually HP I think you will find that forest clearing in England was more unrestrained harvesting for shipbuilding and charcoal manufacture rather than peasant harvesting of dead fallen wood; combined with land clearing for sheep and cattle grazing.
It is one point of view

[Happy Pirate]

With respect happy pirate I dont think we can really compare bushwalkers taking small amounts of wood nearby for small fires to british peasants that would have been taking much larger quantities for day to day life.

That is certainly true, but look at popular State Forests where firewood collection is open slather and not only is there NO light or medium flammable vegetation but generally obvious damage to standing veg as well.
I like a fire as much as the next half-mad pyromaniac but I certainly respect no wood collection rules because the effects in many popular areas are noticeable.
My point was really that the adoption of a British medieval feudal law is not a considered idea and not much good environmental management is noted from this era.
There wasn't much ship-building in the medieval period, it was I think, clearing more for firewood, building and agricultural expansion.
Maybe I should have mentioned the 'Tragedy of the Commons' instead.
Steve

[Happy Pirate]

Interesting website Icefest. Thanks for the link however i didnt find that article interesting or informative at all on the matter.

I did like some of the other articles there tho.

I guess re: the fuel reduction burns article i think its pretty vague, too vague. Im more interested then ever these days and constantly find myself in the middle between all bush user groups. Its very frustrating.

All that article needed was some bs comment about alpine grazing to top it off. (For the record im 110% against alpine grazing).

Travis.

I agree Travis
I think there are a lot of issues missed in the current Conversation articles.
I keep meaning to add my piece but the discussions at TC generally have been getting pretty vitriolic of late and there's only so much I can deal with before I bite.

But I'll add my 2c here...

I was out looking at a reduction burn near Townsville the other day and the burned area (Townsville Common swamplands) had about 80% canopy scorch (% of canopy burned above burned ground - my own metric), which to my mind indicates a fire lit too late and burned too hot. A fuel reduction burn has no need to burn the canopy and the loss of over-story or high-level understory only contributes to loss of habitat, canopy herbivory and aerial predation protection as well as micro-climate drying and further dry fuel accumulation.
From a bureaucratic POV it was probably a 'success': a quota was fulfilled, a milestone accomplished, a management target met. But ecologically this was less a 'prevention burn' than just a burn. Little damage was prevented and no habitat or vegetative function preserved.

In thinking of this discrepancy my gut feeling is that the issue is less about our understanding of the landscape than about bureaucratic regulation which forces managers to burn later in drier conditions than is most conducive to the landscape.
When planning a burn (I'm guessing) you have to; consult with advisors, have the necessary qualifications, have approval from managers, fill out the required paperwork, make sure all insurance, OHS, WHS protocols and departmental guidelines are followed, conform with council and government or ministerial directives, give reasonable notice to the CFA, neighbors, council and community and close the area (after issuing closure notices ahead of time).
To then go and drop a match in the grass, only for it to fizzle after a few square metres would be deemed a 'failure of planning' at a huge perceived cost rather than the successful replication of true mosaic burning that it is.
Real mosaic burning then, could only be replicated by people living full-time in the landscape who are able to daily 'nibble away' at fuel accumulation without greater impact; unrestrained from the overarching hierarchies that force an over-blown 'successful' outcome.
Maybe we need to define the measure of success as small, local and having little or no impact on canopy or ground habitat.

The other issue missed in The Conversation's discussion on fire and climate change (and on climate change in general) is that many of the effects of climate change on the landscape will be almost entirely masked by contemporary landscape modification.
The effect of climate change (while undoubtedly real) will be negligible in a landscape compared to the problem of forest cutting and clearing for roads, settlement and infrastructure. Landscape clearing exposes forested areas to micro-climate change through exposure to drying wind in forest breaks and edges. The fragmentation of continuous vegetation cover may increase its flammability dramatically.
http://www.pnas.org/content/early/2011/08/24/1110245108.short

Interested in what you think
may bite the bullet and copy this into The Conversation
cheers
Steve

[DaveNoble]

A question regarding the recent Winmalee bushfires.

The first Winmalee fire was in September (see http://www.news.com.au/national/breakin ... 6718141345) and I understand that this was caused by a control burn and then some unexpected weather. According to the article 1000 hectares was burnt out.

Now the question I want to ask, and someone may be able to answer. Was this area re-burnt in the more recent fire? Did this big burnt out area change the new fire in any way? e.g. slow the fire down or prevent damage to houses nearby?

Dave

[Happy Pirate]

A question regarding the recent Winmalee bushfires.

The first Winmalee fire was in September (see http://www.news.com.au/national/breakin ... 6718141345) and I understand that this was caused by a control burn and then some unexpected weather. According to the article 1000 hectares was burnt out.

Now the question I want to ask, and someone may be able to answer. Was this area re-burnt in the more recent fire? Did this big burnt out area change the new fire in any way? e.g. slow the fire down or prevent damage to houses nearby?

Dave

Dave
I don't know the area or the fire but I can tell you that an area of tropical grassland burned out by reduction burns won't burn again for 2 - 3 years.
With a true run-away (hot burn) in that area it's pretty certain you won't get another burn for 4-8 (guess) years but extinguished fires can re-ignite from further fires if they have left-over fuel remaining.
In the Blueys though if the original fire was just a ground fire (and if it got away it certainly wasn't) then the canopy could still catch from airborne embers but would be harder to travel with no ground fuel to provide continuity and updraft.
Does that not answer your question?
Steve

[DaveNoble]

Does that not answer your question?
Steve

Thanks, but not really.

I am fairly naive on these matters, but one would think that if an area had a control burn, and the fact that the control burn turned into a bushfire and burnt out a lot more than was intended - and then there was another bushfire in the same place a month later - then one could perhaps conclude that the first control burn didn't actually do that much to prevent or limit the second fire. Now - as I said - this is my naive view based on almost no factual information about where the two fires actually went and where the houses were burnt down. Perhaps someone with good local knowledge can shed a little more light on this matter?

Dave

[Happy Pirate]

Does that not answer your question?
Steve

Thanks, but not really.

I am fairly naive on these matters, but one would think that if an area had a control burn, and the fact that the control burn turned into a bushfire and burnt out a lot more than was intended - and then there was another bushfire in the same place a month later - then one could perhaps conclude that the first control burn didn't actually do that much to prevent or limit the second fire. Now - as I said - this is my naive view based on almost no factual information about where the two fires actually went and where the houses were burnt down. Perhaps someone with good local knowledge can shed a little more light on this matter?

Dave

Hey Dave
The problem is partly the issue of scale and part of liability.
The specific areas where the first fire burned are almost certainly not going to burn again in a hurry.
But a 'region' could be referring to anything from a localized area to a few post-codes.
If a controlled burn got away it probably didn't do what it was meant to so it could have left unburned fuel in unintended areas.
I agree it needs more local knowledge to clarify. Am also interested in any local knowledge.

The problem sometimes can be that some urban dwellers approach the issue of reduction burns almost at the level of conspiracy theory (not accusing you).
The truth is sometimes burns get away. Burns possibly get away more in peri-urban areas because they need to be more confined and thus have more definitive limits. If so it's possibly because earlier burns were repressed or cancelled because of resident pressure.

It's certainly not an easy problem to solve but in the heat of anxiety some people demand simple demand simple scapegoats.

I hope you find out more and please post any info you come across.
cheers
Steve

[maddog]

An article in the Conversation blames climate changes, rather than aboriginal burning, for a loss of megafauna. It is claimed that burning had a negligible impact on fire sensitive vegetation on which the megafauna depended. It is suggested that the colonists may have been highly skilled in using fire to manage landscapes.

http://theconversation.com/did-fire-kil ... auna-19679

[Moondog55]

@ Happy Pirate
Actually I would guess that it depends on your definition of Medieval, but if you accept that Henry 8th was a Medieval monarch then that was a time of huge ship building effort and the deforestation at that time was considered a matter of national importance ( Security of the realm and all that) as was the continuation of that work under ER1
Truth is I have no answers to the original query apart from what I was taught during CFA lectures, but I agree it has ( at the moment anyway ) more to do with politics than real science.

[Happy Pirate]

An article in the Conversation blames climate changes, rather than aboriginal burning, for a loss of megafauna. It is claimed that burning had a negligible impact on fire sensitive vegetation on which the megafauna depended. It is suggested that the colonists may have been highly skilled in using fire to manage landscapes.

http://theconversation.com/did-fire-kil ... auna-19679

I haven't read this one yet but these articles appear every so often claiming to have 'proven' one side of the argument or the other. There are articles on TC that make the opposite claim to this one.
Actually this one doesn't 'blame' anything for MF extinction; although it does argue against burning, it doesn't argue against hunting.
I have enormous respect for Dave Bowman so will take what he says more seriously than some but there do appear to be some logical gaps that have been glossed over.
I do find that a fair number of the articles denying aboriginal influence in megafauna extinction, vegetation change, continental climate modification (yes this too - references available) tend to be written by anthropologists rather than paleo-ecologists. So I wonder if there is an anthropomorphic apologetic attitude here.
Unfortunately this is one area of research that provides a good example of the failure (?) (or short-term manipulation) of science (and I say this hesitantly, as a science graduate and firm arguer against sloppy thinking) where ideology drives research and the fuzzy condition of data allows personal readings based on any desired outcome.

Truth is we'll probably never know.
Steve

[maddog]

I haven't read this one yet but these articles appear every so often claiming to have 'proven' one side of the argument or the other. There are articles on TC that make the opposite claim to this one.
Actually this one doesn't 'blame' anything for MF extinction...I do find that a fair number of the articles denying aboriginal influence in megafauna extinction, vegetation change...

I concede that holding indigenous peoples responsible for megafauna extinction as suggested by Diamond, Flannery ' etc., may sully the imagined purity of the 'original custodian' (and thus be of political concern to some). Notwithstanding this, the paper touted in the Conversation (Sakaguci et al., 2013), clearly holds climate change responsible for megafauna extinction. Citing a paper by Miller al al. (Science 2005), Sakaguci et al. explain the opposing argument:

…burning is postulated as the key driver of the mass extinction of megafauna in Australia…through altering vegetation to fire-adapted plant communities.

In contrast, Sakaguci et al. claim that:

…climate change overwhelmed any modifications to fire regimes by Aboriginal landscape and megafaunal extinction, a finding that probably applies to other fire prone vegetation across Australia.

And conclude that:

Our results…provide evidence in direct opposition to the view that Australia was subjected to an 'ecosystem collapse' owing to sustained Aboriginal burning during the last glacial period.

(Miller et al. had rejected hunting a key driver of megafauna extinction, and Sakaguci et al. did not pursue the line of enquiry.)

Cheers

[climberman]

http://espace.library.uq.edu.au/view/UQ:306407

Climate change frames debate over the extinction of megafauna in Sahul (Pleistocene Australia-New Guinea)

Wroe, Stephen, Field, Judith H., Archer, Michael, Grayson, Donald K., Price, Gilbert J., Louys, Julien, Faith, J. Tyler, Webb, Gregory E., Davidson, Iain and Mooney, Scott D. (2013) Climate change frames debate over the extinction of megafauna in Sahul (Pleistocene Australia-New Guinea). Proceedings of the National Academy of Sciences of the United States of America, 110 22: 8777-8781.

Argues that there's very poor evidence for human extinction of megafauna.

[maddog]

Critics of Flannery's Aborigines killed the megafauna hypothesis:

http://www.abc.net.au/science/future/theses/theses1.htm