Greg Hunt, Opposition spokesman on climate action and environment explained how they are going to do it with soil carbon sequestration:
"We are talking about a land mass, if you are achieving the 150 million tonnes [of CO2 per annum], of an area of roughly 100 square kilometres. Not tens of thousands, but 100 square kilometres of intensive agriculture would make an extraordinary achievement on many of the estimates."
Impressive. That's 1.5 tonnes per square metre so you'd be laying down a half metre seam thick of coal every year. When queried about this, rather than saying that he missspoke, Hunt said he had his own definition of "100 square kilometres":
"When I talk about the 100 squared, that's all about a hundred by a hundred square kilometres or a hundred kilometres by a hundred kilometres, 10,000 square kilometres, a million hectares. You can play a game, respectfully, or we can be serious about what's the calculation here. A million hectares at a 150 tonnes of C02 equivalent per hectare is the figure that we're talking about, but that's the intensive number."
On his website, Hunt has posted an altered transcript of his interview, replacing "100 square kilometres" with "100 squared kilometres":
"Not tens of thousands, but 100 squared kilometres of intensive agriculture would make an extraordinary achievement on many of the estimates."
So "tens of thousands" of "squared kilometres" would be 20,000 km by 20,000 km, which is more than twice the land area of the entire Earth. More importantly, he still seems to be optimistic by factor of about a hundred over the estimate from CSIRO's Jeff Baldock:
"The best estimates that we've come up with right now, which is based on a fairly serious review of the scientific literature that's been published over the last 20 years or so, we see that on a C02 basis, somewhere between 0.3 tonnes of C02 equivalents per hectare per year, up to an upper limit of around about two tonnes of carbon per hectare per year on average."
Hunt is basing his policy on some unpublished research:
GREG HUNT: Well there is a debate, and what we're seeing is that people such as Christine Jones, probably the pre-eminent soil carbon scientist in Australia and one of the world's leading soil carbon scientists, has a very different view. Her view is that Australia can capture an extraordinary part of its overall emissions, far greater than we've proposed. We've been very conservative in our estimates of what Australia as a whole through incentives to farmers could absorb.
STEVE CANNANE: The CSIRO does not take into consideration the field work of Dr Christine Jones because it's yet to be peer reviewed.
Hat tip: Reader Tim.
So at an upper limit of 2T/Ha/yr we'd need something like 300 million Hectares, or 3 million square kilometres of land to suck up our emissions (provided it was managed properly and the carbon stayed in place) which would be around 40% of Australia's landmass. And that's only good for about 10 years or so till the soil reaches its maximum carbon, so what do we do in 25 years?
I've heard these claims being thrown around so much but no one ever seems to do the mathematics of it all.
Hunt has altered his website so that "square" has been changed to "squared".
Perhaps Hunt's PhD should also be scoured for the likely similar errors.
If carbon was so easily collected for putting into the soil for significant sequestration, then it should also be a viable source of reduced matter for harvesting for burning for human energy requirements.
It's not, so it isn't.
Greg Hunt and the soil sequestration enthusiasts need to consider the thermodynamics of the process. I think that they're creeping toward being the carbon sequestration equivalent of over-unity energy wingnuts.
Bill O'Slatter @ 2
Nitpick: Greg Hunt doesn't have a PhD. He's got an honours degree in Law and a BA from Melbourne Uni and a Masters in International Relations from Yale. His honours thesis, written in around 1990, was on Carbon trading. I haven't read it (and I have no intention to), but I gather the gist of it was carbon trading can't work because petrol and electricity are demand inelastic.
Even if this were true, (and there is alot of evidence to suggest that it isn't), it, of course ignores substitution of supply sources and and the like, as well as competitive advantages for firms that are more efficient in their use of said supposedly inelastic good.
At least he's not a denialist though...
Some (random) comments on carbon-in-soil sequestration:-
This C-in-soil idea comes from studies of a soil in the Brazilian rain forest. Just like cane toads, somethings just don't import well, the conditions are not the same in Aus. So, yes soil carbon is stable in anoxic soils (rain forests, swamps, lake sediments) but aren't the majority of Aus soils oxic?
In the sneaky suspicion class is my feeling that since Aus flora have adapted to a frequent bushfire regime, so will the soil biota have adapted to recycle carbon. If you're a bug in a C-poor soil, and there's a free lunch sitting there (C as charcoal), would not a bit of quick adaption give you a boost?
In terms of paying someone to apply C-in-soil, there is still no method to measure soil carbon beyond sampling and lab work so we can't see whats happening over broad areas.
Finally, I feel politicians pushing dodgy, untried science as a panacea for anything brings us to where the Soviet Union was with Lysenko, i.e.in loony land. (I'm surprised My Lysenko is invoked more often as to what happens when nations abandon real science and instead follow fantasy. Its never a happy outcome.)
As long as Greg Hunt is debating whether 100 km x 100 km = 100 sq km or 10,000 sq km, can we also have a debate over whether 1+1 = 2, 3, 4 or 5? That's got to be way overdue.
My calculations show that, using the CSIRO estimates quoted above, to capture the 150 million tonnes of carbon per annum that Greg Hunt says is possible, would take between 10% and 65% the area of Australia, or between 3 and 21 times the area of Victoria. That is, not the 100 sq km nor the 10,000 sq km but between 750,000 sq km (at 2T/ha/year) and 5 million sq km (at 0.3T/ha/year).
(Can someone else check? Surely Hunt cannot be out by so much!)
Bruce D - I agree with the rest of your comment but it isn't true that "Aus flora have adapted to a frequent bushfire regime". They haven't even adapted to an infrequent bushfire regime. They haven't adapted to fire at all, in spite of the popular misconception, although some of them can come back after fire, just as they can come back after other disasters. So there probably aren't any bugs just waiting to eat the charcoal, although I agree that the proposition, however much it may contribute in some very small way in the short term, is of no use whatever in the longer term or in the amounts needed to deal with out CO2 emissions. If Greg really thinks we can just go on emitting more and more CO2 and compensate by burying more and more charcoal he is not as smart as I thought he was. I had thought that, along with Turnbull, Hunt was one of the few Liberal MPs who was living in the world of reality and science.
Hunt is very sloppy. Lenore Taylor busted him the other day for circulating a press release pointing to Sarkozy's decision to abandon a carbon tax for France as a warning to Gillard (this was apparently the delusionist central talking point for the day). An hour later he had to send out a revised version noting that it was actually the one year anniversary of this decision.
And I caught him not so long ago out by a factor of five on the impact of a carbon tax on electricity bills.
I have a good idea. If we bury the Coalition in a disused coal mine, Australia's CO2 emissions will fall exponentially. Stands to reason.
bruced, the process you are referring to is known as Biochar and is the process which developed the Terra Pretta soils in the Amazon, the process is to produce charcoal, grind it up and mix it in with the soil, pores in the char provide habitat for bacteria and also hold on to nutrients (this is all from memory so I hope I've got the details right). The charcoal itself is quite stable and takes a long time to decompose, I haven't heard a great deal about biochar recently but burning and digging ash and charcoal into soils to improve fertility has been done for centuries, whether the claims stack up to what it's promoters say I don't know.
The main methods of sequestering carbon in soil is from techniques such as cell grazing, minimum tillage and pasture cropping, these methods increase organic matter in the soil (and improve fertility and moisure holding capacity, as well as minimising soil erosion and fertiliser inputs), increased root mass and invertebrate activity is what accounts for the increase in carbon.
I'm still waiting to see the long term results of things such as biochar but having a fair involvement with agriculture I can tell you there is a lot of woo out there, exhaust emissions fertiliser, biodynamics, natural sequence farming (though admittedly the last 2 do have the occassional good idea).
To put this error into perspective, the Libs policy relies on soil carbon for 85 million tonnes or 61% of their proposed carbon reductions of 140 million tonnes by 2020. So it's fundamental to their 'strategy'. (They propose paying farmers $8 to $10/Tonne of carbon in soil.)
The remaining 55 million tonnes saving is attributed (without allocation) to reduction in emissions from electricity generators and industries, forestry measures, waste coal mine gas, transport, green buildings and energy efficiency (and possibly landfill - it's hard to read the chart).
Not only that, but their proposal is to take all this from consolidated revenue, which presumably would require either a tax hike or a big cut in other government programs or additional borrowing and an increase in the budget deficit.
They really need to go back to the drawing board.
Where will the carbon come from? To achieve the levels Hunt wants the existing rate of natural carbon capture and sequestration that occurs through agricultural practices would surely require an exponential increase. Perhaps he envisages that some technology would be developed to capture solid carbon somehow separated from the carbon dioxide (for example)coal burning power stations?
Or there is the great hope of the perpetual motion machine...
it isn't true that "Aus flora have adapted to a frequent bushfire regime". They haven't even adapted to an infrequent bushfire regime. They haven't adapted to fire at all, in spite of the popular misconception...
In what sense have they not adapted to fire? As you say,
some of them can come back after fire
which is why, in the presence of fire (which began increasing in frequency with a drying climate at least as long ago as the middle Miocene ~15 million years ago), fire-tolerant (and, in some cases, fire-dependent) species such as Eucalyptus and Acacia gained a competitive advantage over pre-existing fire-sensitive flora (such as Nothophagus-dominated rainforest), which lead, ultimately, and not forgetting the rapid intensification of this process caused by anthropogenic use of fire, to a marked shift in composition towards the, er, fire-adapted vegetation we see today - no?
Yeah, I noticed that too, foram. As a professional revegetator I can only say 'eh?' (And here was I about to perform the traditional extraction of seed from a bunch of Banksia pods by setting fire to them...)
Not all Australian ecosystems or plants are adapted to fires (and most of Australia's animals don't 'regenerate' too well after fires either). And I can attest to the fact that some patches of forest burnt by big hot fires take a very long time to recover and likely will never return to their previous composition. Given the greater frequency of fires with global warming, some grass and other species like orchids (and other plants and animals restricted to small habitats) probably disappear altogether before we even know of their existence.
Bernard J gave another example here regarding the Gondwanan Nothofagus forest in the Great Dividing Range:
Even if we were to reduce emissions by 140 million tonnes in the next eight or nine years, which is looking unlikely under Labor and impossible under Liberal policy, that would still leave about 260 million tonnes being added to the atmosphere each year from Australia.
We and the rest of the world will need to do a lot better to restrict the temperature hike to 2 degrees Celsius. Current pledges look like taking us to 3.9 degrees Celsius.
Looks as if the estimate in my previous post is out quite a bit. Going by this page: http://www.climatechange.gov.au/en/government/reduce/national-targets.a… , the 2000 emissions were around 550 million tonnes not 400 million tonnes.
Different sources or different measures? Does anyone have actual data on this? Most reports seem to only talk about percentage reductions etc.
Sou, thanks for the read - and as an aside, Bernard J's mention of pyrophilic eucalptus associations did make me feel slightly better about my egregious misspelling of Nothofagus :-)
foram - no.
Christine Jones "probably the pre-eminent soil carbon scientist in Australia and one of the world's leading soil carbon scientists"?
As a check of the Web of Science will show, Dr Christine Jones' record of peer-reviewed journal publications in the field of soil carbon consists of ... nothing. I stand to be corrected, but her lifetime citation count looks like it is in the range 40-50 (any "eminent" scientist would have over 1000 citations to their work) and her last peer-reviewed paper of any kind appears to have been in 2003.
Greg Hunt should be called to account for this.
David - why not?
Specifically, why have bill's Banksias not adapted to fire at all?
Thanks for reminding me of the extraordinary 'conversation' with Shub Niggurath. I hadn't seen the last post of his, and those of several others, as my hard-drive died taking all of my bookmarks with it. Thanks also for the climateinteractive.org link: I was thinking about this sort of data presentation just last week and it's good to have some links now to exactly this stuff.
I too am curious about your comment that no Australian flora species has:
...adapted to fire at all, in spite of the popular misconception, although some of them can come back after fire, just as they can come back after other disasters.
Perhaps you are using a different interpretation of what an 'adaptation' is, but I am curious about what the charring 'ironbark' of many eucalyptus species represents, or the 'socks' of some bluegums and backbutts, or what seed germination responses to butenolide and other smoke-derived compounds represent. The banksia question comes into this too, and there are other characteristics that most would accept as fire adaptation; if they are in fact not, I'd be keen to find out why.
Bernard, more thanks are owed to you.
I learnt a lot from that particular biodiversity thread despite, or perhaps because of the idiocy/ignorance displayed by some of the posters, but particularly because of the terrific contributions from you and Jeff Harvey.
Sure the libs can't do anything more mathematically demanding than counting cash, and biochar is not the silver bullet they so desperately want it to be. However done properly biochar is carbon-negative, turns sewerage into energy, and improves the water retention/micro-ecology of soil, what's not to like?
Let's not ignore what is basically a good idea just because it's political patrons get confused when more than one dimention is in play.
Alan, I don't see any mention of biochar in the Liberal Party policy here:
Perhaps they are considering it, although it's not mentioned in the policy paper. So far I've only read their discussion of replenishing soil carbon on farms, which reads as if this is more what they have in mind:
If they were considering biochar, I'd have thought they would be talking about setting up pyrolysis plants etc.
The convention is "100 square kilometres" usually refers to 100 (km2) rather than (100 km)2. I'm not sure how much this is lousy communications skills versus scientific innumeracy.
Neither of which is good, of course, but they're different problems.
I wanted Greg to express the territory required to make progress on sequestration in millionths of a moon surface (it's 2.6 micromoons) precisely because I knew the alarmists would not quote him accurately and would use scare figures like tens of thousands of hectares just because they make up a hundred square hectare square.
I think he's learned his lesson, but shame on Tim Lambert for this yellow journalism!
OK guys, foram, Bernard J. Too much ground to cover for a post, but in brief. The things that are presented as "fire adaptation" are actually adaptations to other things ( eg in case of banksias heat, drought, nutritional status, protecting seed from seed eaters, ensuring gradual release of seed - heat speeds up this process and releases seeds, but after a bushfire, releasing all your seeds in this way would be a poor "adaptation"). A fire can result in recovery in a few species because of these adaptations, but most species of plant aren't adapted to disaster and fire wipes them out. The business about an ingredient in smoke stimulating seed growth applies to all kinds of species including domesticated vegetables never naturally exposed to fire, and is best from burnt grass straw, ie has nothing to do with smoke from burning eucalypts etc, it is just a general plant physiological response to a chemical. No animal species are adapted to fire.
There is no evidence that Aborigines increased the amount of fire in Australia, or that their use of fire had a particular purpose (other than for hunting), or that it had any effects on vegetation patterns
I fear that soil carbon could become a form of rural pork barreling the way corn ethanol is in the US. There is also the moral hazard of convincing ourselves the amounts and permanence of CO2 withdrawal are bigger than they really are. Instead the no.1 priority should be to burn less coal.
As a practical measure wouldn't 'carbon farmers' have to refund the money if their carbon sink went bad? Fire, dieback, drought or waterlogging could turn sinks into sources. Heaven forbid if we had to shut down coal fired power stations.
David H, you are, of course, welcome to believe what you like - and apparently you do!
But for the rest of us your argument remains, um, rather baffling. From wikipedia, at the link I provided above -
The key adaptations of fire-induced serotiny are a cone or woody fruit that provides protection from the heat of fire, together with a mechanism by which the passage of a fire can trigger seed release. Typically this mechanism is a resin that seals the fruit or cone scales shut, but which melts when heated. This mechanism is refined in some Banksia by the presence inside the follicle of a winged seed separator which blocks the opening, preventing the seed from falling out. Thus the follicles open after fire, but seed release does not occur. Wetting of a follicle causes the wings to pull together, and then reflex back out again as the follicle dries. The seed separator thus acts as a lever against the seeds, gradually prying them out of the follicle over the course of one or more wet-dry cycles. The effect of this adaptation is to ensure that seed release occurs not in response to fire, but in response to the onset of rains following fire.
Serotiny can be understood as an adaptation to an environment in which fires are regular, and in which post-fire environments offer the best germination and seedling survival rates. In Australia, for example, fire-mediated serotiny occurs in areas that are not only prone to regular fires, but also possess oligotrophic soils and a seasonally dry climate. This results in intense competition for nutrients and moisture, leading to very low seedling survival rates. The passage of fire, however, reduces competition by clearing out undergrowth, and results in an ash bed that temporarily increases soil nutrition; thus the survival rates of post-fire seedlings is greatly increased. Similar pressures apply in Northern Hemisphere conifer forests, but in this case there is the further issue of allelopathic leaf litter, which suppresses seed germination. Fire clears out this litter, eliminating this obstacle to germination.
I could go on, but I don't actually think this is the core of the issue under discussion.
bill, while whoever wrote the Wikipedia piece clearly believes what you believe, that doesn't make it correct. But I agree we are way OT - I originally just responded to the proposal that since Australian vegetation was "adapted to fire" there may be bugs in the soil that were "adapted to charcoal". Neither is true, but I then got several responses demanding that I explain Banksia seeds and "smoke adaptation" and Eucalypts sprouting from trunks and so on. There is actually a whole literature on this stuff, and the popular beliefs about fire in the Australian environment are just that, popular beliefs. To say that Australian forests are adapted to fire is a bit like saying that grass is adapted to lawnmowers.
The DA proposal of the Opposition calls for âbusiness as usualâ with taxpayer funded financial rewards offered as incentives for business to voluntarily reduce CO2-e emissions. By contrast, government proposes to place a cap or limit on the level of emissions which may be made each year by the leading one thousand CO2-e emitters and imposes penalties on those who do not comply.
In each case, the outcome aimed for is that by 2020 Australiaâs emissions have been reduced by a purely tokenistic 5% below 2000 levels. Given that there are only 10 years left to the target date (2020) this calls for annual reduction of 0.5% of the 535 million tonnes emitted in 2000 (27 million tonnes), plus 0.5% of increase in emissions (15 million tonnes) which occurred during the decade 2000-2010 (about 0.075 million tonnes) plus 5% of subsequent annual emissions (estimated as 3% growth or an average 18.91 million tones) occurring in 2011-12 and each year thereafter.
In summary, to achieve a 5% reduction on 2000 emissions by 2020, Australia needs to reduce its emissions by an average of about 61m. tonnes per annum from 2011-12 to 2019-20, a total of 550m. tonnes over the period. Failure to achieve the annual target simply increases the target which must be met in future years, if the decade total is to be met. Further it is far from clear that the DA proposal addresses the conservative 3% annual growth in demand for energy.
It is unlikely in the extreme that annual targets of this magnitude could or would be met by the DA scheme at the carbon price being offered by it. That price is simply too low. To achieve a 5% reduction target, industries responsible for emissions would have to be offered much higher inducement than a carbon price of $10-$15/tonne to develop and adopt alternative technology or reduce their use of fossil fuels. Even if a more realistic $25/tonne were offered in 2011/12, under the DA proposal, response of industry would be entirely voluntary since it involves no compulsion or penalties, with one ill-defined exception.
Finally, to make charcoal one has to burn wood in anoxic conditions but where does the wood come from and how does this affect ânaturalâ sequestration. Just how many trees are going to be chopped down top produce the charcoal which is then ground-up and buried in the soil?
Whilst this fire issue might seem off-thread, I think that is has an indirect bearing that might become apparent with time, so I will persist with it for at least this post.
David Horton, I actually agree with a great deal of your take on fire in the Australian landscape, and most especially on the misapprehensions of the reasoning behind - and the effects of - prescribed burning. Fauna are extremely poorly adapted, or completely unadapted, directly to fire. Similarly, most plant species are not adapted to the frequency and ubiquity of artificialy-set fires that are used by humans to reduce 'fuel' load. Fauna may however be adapted to plant associations that succeed after a fire, and this surely is the reason for 'firestick' burning (if not, why do aboriginals fire their environment?).
However, I would not go so far as to say that no plant species is adapted to fire. Fire is a natural part of the environment, even if it is not as common naturally as humans now make it, and thus it is inescapably an evolutionary pressure. Organisms respond to all fitness-affecting pressures in their environment over evolutionary scales of time, and the presence of fire is not exempt from this.
One of the things that I think might obscure your acknowledgement of evolutionary response to fire is that a specific 'adaptation' can occur in response to multiple pressures simultaneously, and be moulded and modified by each. It is for this reason that I did not list epicormic budding in eucalypts as a fire adaptation (I'm not sure where that came from) - it also serves as a regrowth response after branch loss during drought, after herbivory, after pathogen attack, or after physcial damage by storms. And of course, there are other pressures that can be advantageously responded to by epicormic growth.
This is not to say though that epicormic growth doesn't provide a fire-response benefit, and that its development hasn't been in part shaped by fire. Similarly, lignotuberous storage provides benefit against herbivory, against drought, and against snow damage, but how is it that it apparently provides no benefit against (and is thus not shaped by) fire?
If a seed case provides protection against insects or drought, it doesn't necessarily mean that it only provides protection against insects or drought. Similarly, if many apparently non-'pyrophilic' species show germination responses to smoke-derived chemicals, it doesn't mean that some are not specifically adapted to the presence of smoke (or that others don't have a relevant, fire-related explanation for their smoke-response). I have a number of SW Australian natives whose germination is enormously enhanced by application of smoke water: if such a response is not an adaptation to fire, what is it?
And whilst I agree that soils are unlikely to be seething with organisms "adapted to charcoal", one needs to keep in mind that life has a habit of developing extremophiles that are able to survive in the presence of - and to actually utilise or otherwise thrive in - oil, heavy metals, arsenic, anoxic environments, high temperatures and sundry other apparently life-unfriendly environments. If there is a way that charcoal-rich environments may be directly or indirectly used to the benefit of an organism, I am sure that such adaptation has already occurred, or will occur in the future.
Such an adaptation would have implications for any future large-scale carbon sequestration of biochar, and thus should not be discounted out-of-hand.
Going by her CV, Dr Christine Jones worked with the land/water dept in NSW for a time (1998 - 2003) after which she set up her own business.
(I'd disregard the early years - that's probably when she was studying or her early career. She has since changed direction towards soils.)
I would say she has experience in soil tech etc. She promotes good land management practices based on conserving nutrients including carbon, and obviously sees an opportunity in renewing soil carbon on farms. She doesn't seem to have published much recently, but attends symposia and field days etc so is probably active as a consultant/farm adviser.
This is an article she has written, don't know when (looks like April 2009 from the file name). It's a bit mixed up in 'messages' - probably written for a farmer or lay audience.
Here are some on-ground data on soil carbon renewal trials (same site I linked above) - looks to be mostly USA. Seems to support the estimates provided by CSIRO.
I agree with Johnno re what happens when soil carbon depletes on farms that have received payment? Eg during the next big drought, change of farm practices etc.
I can understand why this has not been picked up by the UN, and why Australia and the USA wants it included! (Australian agriculture is generally not bad as far as minimum tillage/no till, stocking rates etc goes; although there's always room for improvement.)
Bernard that is a good and subtle question. I guess the answer in short would be that Australian plants have adapted, over millions of years, to the fundamental features of the Australian environment (speaking generally here), including thin soils, low phosphorus, hot dry summers with frequent droughts, low organic content soils; as well as to the kinds of grazing and browsing animals present. Fire was so infrequent, its intensity so unpredictable, and the levels of survival of individuals so random, that it is hard if not impossible to see how its action could have enhanced features evolved for other reasons. Indeed if it did it could well be that such change may have reduced the adaptive value of the features to the more common features of the environment. It is quite clear that the vast majority of Australian plants can't survive fires, especially frequent fires, and this also suggests that it is not possible to develop fire adaptations per se. A helpful analogue might be "adaptation to cyclones" - there are plants that can recover after having all their leaves stripped off, their branches shredded, their trunks blown over, their roots waterlogged following a cyclone, as a result of some general survival mechanisms, but we wouldn't consider them as having adapted to cyclones.
The smoke enhancing of germination appears to be the result of a single chemical in smoke, and the effect occurs in all kinds of vegetables that could never have adapted to smoke in the environment (an even more impossible adaptive process).
Since I published "The Pure State of Nature" Allen & Unwin, 2000 (out of print but available in many libraries and online as http://davidhortonsblog.com/history/) there has been a great deal of further work on these questions. Some recent publications are:
Vital Importance of Habitat
S. Don Bradshaw
Australasian Science November-December 2009
Mooney, S.D., et al., Late Quaternary fire regimes of Australasia, Quaternary Science Reviews (2010) doi:10.1016/j.quascirev.2010.10.010
Little evidence for fire-adapted plant traits in Mediterranean climate regions
S. Don Bradshaw, Kingsley W. Dixon, Stephen D. Hopper, Hans Lambers and Shane R.Turner
Trends in Plant Science February 2011
If you are interested you could probably track these down through a library or purchase online.
It seems to me that any attempt to pay for biosequestration would need to have payments quantity/time specified -- e.g. kg/days, ton/years so that in the event that some event causes a flux the sink operator is not in debt.
You would need some pretty robust auditing too. Unlike agistment of livestock, it's a not so obvious when someone is cheating.
More boradly, I wonder what the EROEI and more general ecological footprint of these places would be. It's one thing for someone to plan on sequestering 0.3 tons per ha in prime agricultural land with good rain with a minimum of energy inputs. One suspects that hardly anyone is going to give up using this land for $8-$10 per ton -- especially if that has to be recovered over 100 years.
In practice, you are going to have to use land that is very marginal at best or worse. If you are going to gow lucerne on it you are going to have to irrigate it, maintain topsoil and so forth. That won't be cheap in energy terms.
Essentially, this biosequestration caper is the CO2 equivalent of stuffing your rubbish into bags and dumping them in the garage. Sooner or later you run out of space and of course, you still have the rubbish. Carbon sinks including the human-contrived ones, are themselves a finite resource and will require recurrent human inputs. How much carbon can be locked up in soils indefinitely needs to take this constraint into account.
Short Answer: there's no easy way to stick a geological era's worth of carbon back in the ground.
And by "easy" I mean "conceivable".
David Horton and Bernard J, thanks for the patient responses and some fascinating discussion - it's always refreshing to have one's mental models given a good shake. I don't wish to let Greg Hunt off the hook by hijacking this thread with a discussion of fire 'adaptations' or the lack thereof, however I will admit to remaining skeptical (in what I hope is a healthy sense) about how far David extends the argument that none of the traits that are now of selective advantage in the present fire-prone environment can be considered fire-adaptations per se (although I agree that many such adaptations may have developed initially in response to other selective pressures).
For example, you say "after a bushfire, releasing all your seeds in this way would be a poor 'adaptation'" yet such a strategy confers two potential advantages: 1) allowing seed to germinate in a sterile bed, free from attack by fungus, and 2) access to mineral nutrients that may normally be 'tied up' within the vegetation, before they are taken up by other plants, or washed or blown away. I take your point about how fire-enhancement of features adapted for other reasons might reduce the effectiveness of such features for their original 'purpose', however I would suggest that such enhancements do exist, and could, at least in some cases, be considered genuine adaptations to fire. For example, the observed depth of epicormic structures in the eucalypts - which ensures their insulation from quite hot fires - would likely impose an unnecessary energetic cost on the plant in the absence of fire. Just a thought - and enough off topic from me.
Let me say that much learning can go on in comment threads and this is a good example, even one where there is more that a single right answer, but a lot of exploration. Perhaps introducing a variant of threaded comments would be a good idea, with say, a single fork.
As to the origin of this post. This is a major failing of journalists. Someone had to speak up to Hunt and point out that he was full of it. The press agents say what they do because there is no push back.
> evidence for fire-adapted plant traits
Removing fire artificially is one good test. What happens to the ecosystem when policy suppresses fire for decades?
This is indeed an interesting and thought-provoking topic, and hopefully Tim Lambert and the others here will tolerate a little more of the digression down this path.
I was caught on the Hawkesbury River during the fires in January 1994, missing the north-bound closing of the bridge by about 50 vehicles. We were assured for several hours that the closure was only for a few hours, until the Pacific Highway cleared of smoke and visibility would allow passage. After about 3 hours it became apparent that nothing was going to happen for a while, so many people drove into Brooklyn to wait it out at the pub. By about 11:00 pm the fires had moved south to blanket many of the hills across from Brooklyn, so much so that the highway was blocked for about two days in the end, and of course history records how the whole area was basically razed. The sight of the fires was one that I doubt I'll ever forget - it was like looking into the lurid orange and obsidian black pits of Hell.
For a month or so afterward, when I drove north and south each weekend through the Central Coast, the absolute denuding of the bush was astonishing. Where there had been impenetrable bush, as only Australian bush can be, there was smooth ash-blanketted ground with the occasional black trunk poking up. However, what was more astonishing was the speed and vigour with which the eucalypts and banksias burst forth with fresh green growth, and how the bare ground was soon carpetted with grass that would make a golf course groundsman weep with joy.
Now, it is certainly possible to argue that the adaptations that permitted the vegetation to regrow so spectacularly are actually developed in response to insect attack or to drought, but if so, and if there is no influence of fire during the evolutionary selection, then the transference of such responses to a coming-back after fire is extraordinary indeed.
Keep in mind that these were wildfires - from where we were watching on the south bank of the Hawkesbury, we could feel the heat radiating from the fires several kilometres away on the north side of the river. If adaptation to drought and insects can afford such resilience to fires of this magnitude, without any direct selection by fire itself in the plants' evolutionary history, then I would be most surprised indeed.
When I was a lad we had a Hakea salicifolia in our back yard. The seed cases used to fascinate me as a boy, because they'd sit on the branches for years, never opening. The bush grew very slowly through droughts and vigorously through rains, and the cases never opened. Then one day, after a nearby backyard fire to burn off some liquidambar leaves came a little too close, the seed cases miraculously split and came apart. Perhaps this is a drought-adaptation that was triggered by fire, rather than by a drought of suitable intensity, but Ockham's Razor would seem to demand a rather more parsimonious explanation.
You make the comment:
Fire was so infrequent, its intensity so unpredictable, and the levels of survival of individuals so random, that it is hard if not impossible to see how its action could have enhanced features evolved for other reasons.
In response I would argue that intense evolutionary pressure, even if infrequent, can still have a profound shaping effect by natural selection. Many traits are held in a species by infequent events, and many traits persist long after the pressures that produced them have disappeared - the on-going deciduous nature of many plants, transferred to exotic locations that do not require deciduousness, attests to this.
You also say:
Indeed if it did it could well be that such change may have reduced the adaptive value of the features to the more common features of the environment.
Yes, it could be, but in a consideration of such matters it needs to be plausibly evidenced, rather than just suggested. I could just as speculatively argue that infequent but hot firing might enhance the adaptive value of evolutionary responses to non-fire events: what either proposition really needs is some experimental or at least some empirical data from the field.
And to finish for now, you said:
It is quite clear that the vast majority of Australian plants can't survive fires, especially frequent fires, and this also suggests that it is not possible to develop fire adaptations per se.
I completely agree with the first part of your statement, and it is for this reason that I am so alarmed at the wont of governments of all levels, and of the ignorant (and usually red-neck) element of the lay public, to enthuse about the blanket torching of bush across the country.
I diverge with you on the second part of your sentence, as the conclusion does not necesarily follow the proposition. It is quite plausible that fire has not been a common evolutionary pressure on the Australian flora over geological time and space, and the former distribution of rainforest across much of inland Australia would seem to support this. In such a case, there would be a good persistence of fire-sensitive species, event as fire-resistant species evolved in the parts of Australia that were beginning to become more regularly fired (whether by human hands or by climate change is not really germane to the basic point).
I would argue that pyrophilia in Australian flora species was a far less common trait than it is today, and that it was restricted to localised areas and subsequently expanded outward as fires became more common. To the extent that many fire-resistant species are also loaded with volatile oils (not necessarily a fire-adaptation: herbivory resistance is certainly a pressure here), such oil content may have helped in the shifting of the distribution of relative fire resistance in the floral assemblages.
There is a tension between the fire-resistant and the fire-sensitive plant species that is even now exemplified by the dance between sclerophyllous- and rain-forest on the eastern seaboard, although a dissection of the pattern of this dynamic tension, and its root cause(s), would probably bog this thread down too much. Suffice to say that the relationship between Australian plants and fire is a comlex one indeed, and one that I am sure includes some explicit adaptation of plants to fire.
Essentially, though, I think that our difference in interpretation is one of degree, rather than of absolute dicotomous attribution.
Removing fire artificially is one good test. What happens to the ecosystem when policy suppresses fire for decades?
There are some examples that can answer this question, but I predicate a response with the observation that it is dangerous to generalise!
In the areas where I conducted my PhD fieldwork, there were rainforest remnants along the deep stream gullies, surrounded by sclerophyll forest. Historic records indicated that once aboriginal practices were removed the rainforest giants overgrew the eucalypts, and the remnant associations then appear to slowly creep outward over time from the littoral areas. Where fires recur this process is rapidly reversed, with the remnants being pushed right back to the deepest, wettest parts of the valleys, in the face of expanding sclerophyll.
My supervisor related the observation that a similar phenomenon occurs/ed in the Illawara area (and probably in other areas) where regular aboriginal firing gave an open sclerophyll parkland effect at the time that James Cook sailed up the coast. Some of the areas that were open eucalypt forest then (as demonstrated in engravings/paintings) are now rainforest because the aboriginals were displaced by Europeans; although intense urban expansion pressures obscure the degree to which the suppression of fire affects the sclerophyll/rainforest dynamic.
And lest I be accused of excessive OTiness, Greg Hunt is still a ham-fisted numpty when it comes to basic mathematical notation, and to thermodynamic and biological realities.
I can't follow this any more today having medical matters to deal with, and I also have the feeling of being the last guest at Tim's party, overstaying his welcome. Just a couple of quick responses to Bernard in particular. There is no evidence that Aboriginal use of fire had any impact on vegetation patterns, other than in the most trivial short term sense.
"eucalypts and banksias burst forth with fresh green growth, and how the bare ground was soon carpetted with grass " - yes, and this is the picture the media always presents as well. But what the picture ignores is the trees that don't recover (and Banksias are not good generally with fire), and the shrubs and ground cover species and fungi and soil bacteria and so on, that are simply killed by fire.
And foram "the observed depth of epicormic structures in the eucalypts - which ensures their insulation from quite hot fires - would likely impose an unnecessary energetic cost on the plant in the absence of fire." Some species yes, most species no. But the judgement about the energetic cost of thick permanent bark versus thin shedding bark, or small leaves versus large, or volatile oils versus not, or low growth habit versus high, and so on, are all very complex balances in the great "Struggle for Life".
Look, just test your assumptions about fire in Australia, check the foundations for them, I am afraid you will find that they are built on very thin soil indeed.
Which takes us back, naturally, to the story of Mr Hunt and his willingness to play along with the climate denier prejudices of his boss and most of his colleagues, with the honourable exception of Turnbull. it would be nice if Greg came out of the closet and started pushing for genuine solutions to greenhouse gas emissions, rather than the phoney propositions of Abbott that you can have your planet and eat it too. Buying biochar is the same proposition as burying CO2 from "clean coal", just in a different wrapping.
[Ocean Sequestration of Crop Residue Carbon: Recycling Fossil Fuel Carbon Back to Deep Sediments](http://pubs.acs.org/doi/full/10.1021/es8015556)
Environ. Sci. Technol., 2009, 43(4) pp 1000â7
DOI: 10.1021/es8015556 [as PDF](http://www.physics.uci.edu/faculty/2009-Ocean-Sequestr-CROPS.pdf)
"We show here that this method is 92% efficient in sequestration of crop residue carbon while cellulosic ethanol production is only 32% and soil sequestration is about 14% efficient."
I think this required river transport to minimize transport costs.
OT: [An interesting column](http://www.nytimes.com/2011/04/04/opinion/04krugman.html?partner=rssnyt…) from Paul Krugman today on the republican senate hearings farce on climate change, and the headless chook reactions when the Berkeley Earth Surface Temperature project said that they agreed with everyone else's measurements of rising temperature.
> I was caught on the Hawkesbury River during the fires in January 1994, missing the north-bound closing of the bridge by about 50 vehicles.
IIRC that was the time I was driving south towards the Hawkesbury River and wondering about the size of the flames off to the side of the road when I heard a radio report that the highway was closed including a section I was still on. I must have just missed the closure going southbound, saw a huge lineup of stopped cars at the Hawkesbury River bridge northbound, and had to stay with a friend in Sydney until I could get back up north.
Much ado about nothing. 10km squared vs 100km squared. The man stumbled over how you describe an area (a hectare is 100 meters squared, not 100 square metres - half the people get it wrong). Mind you ... I suppose you have a point, in that he said "*not* tens of thousands", when 100km squared is indeed tens of thousands of square kilometres.
"I feel politicians pushing dodgy, untried science as a panacea for anything brings us to where the Soviet Union was with Lysenko"
"They haven't adapted to fire at all, "
Which is why, after a fire, the imported trees are mostly dead and all the eucalypts holler "Thank you, jesus!" and put out bright green suckers within a matter of days. I live in Canberra - don't tell me the trees aren't adapted to fire.
"but after a bushfire, releasing all your seeds in this way would be a poor "adaptation""
Eh? Releasing your seeds after all the weeds around you have been burned is a *great* adaptation! It's a land-grab.
"To say that Australian forests are adapted to fire is a bit like saying that grass is adapted to lawnmowers."
You know about short-stemmed daisies and dandelions? They flower right at ground level, and it's specifically an adaptation to lawnmowers.
You seem to think that "adapted to fire" mens "adapted to being burned to a crisp", which is not what the phrase means at all. Perhaps it would help you if everyone spelled it out longhand: "adapted to an environment where fire is a relatively frequent occurrence, compared to some other environments, to the extent that the plants would do less well in competition with other plants if the fires did not occur".
I've had a question about soil carbon similar to Fran Barlow's comment: how much can you put in per hectare until you saturate? And how long does it stay there?
Biochar seems like a potentially important solution, because along with biomass power-plus-carbon sequestration it seems like a rare, carbon-negative solution. We need to know its limits though.
Plant growth/health requires a fairly balanced carbon nitrogen ratio.
How are the farmers supposedly going to grow food if the soil has an over abundance of carbon ?
Will it further lower the PH of farm soils ?
There would be many adverse affects.
Brian Schmidt: According to what I've heard and read from people promoting this they're talking of carbon levels of up to 10%, though this would only be possible in the best soils and under the best conditions particularly when this carbon is part of organic matter in the soil so the actual organic matter would be around 25% of the soil mass. Obviously ths is pretty high but it does include plant roots and soil organisms (which does help balance the C:N ratio as mentioned by finch).
The carbon increase is mostly in the top 10cm of soil (though one farmer I know has 1% C at 1m depth, which is pretty impressive but that's in very good soils) at 1.5T/cubic metre that works out at 15kg/square metre (if my maths are right) or 150T/ha, pretty high huh? Even if ths were possible it would only be under the best conditions, it assumes the carbon is locked there permanently (not taking into account losses through drought) and there's also the assumption that enough farmers will take this up voluntarily to make a difference (from long experience this will take a very, very long time).
These are the claims I hear, I think it's wishful thinking.
Since we're all doing the OT tango I'll drop back in. I had thought the melting resin, and the winged spacers that then restrained the seed until the next decent rainfall, were about the clearest example of an 'adaptation' to fire one could hope to get, which is why I chose that one point. (You really do need to set fire to the cones of the Banksia ornata - or pop it in the oven for a while - to extract the seeds, you know.)
And I haven't even mentioned Xanthorrhoea!
I generally agree that lignotubers and epicormic budding are not solely an adaptation to fire, but then I'd argue that it's no more legitimate to assign them solely as a response to grazing pressure or drought either. I'm not, after all, arguing for sole attribution!
The depth of epicormic structures in Eucalypts has been raised already, but I'll flag it again. David says
And foram "the observed depth of epicormic structures in the eucalypts - which ensures their insulation from quite hot fires - would likely impose an unnecessary energetic cost on the plant in the absence of fire." Some species yes, most species no.
but those of us on the other side of the argument only have to demonstrate that any species of Eucalypt is fire adapted in this manner to disprove the sweeping claim that no species is!
As a consequence, I still find I am unable to accept the absolute claim 'they haven't adapted to fire at all'!
But it's certainly an entertaining discussion.
I also find the 'Aboriginal burning made little difference' argument rather hard!
Touching on this, where I live in Adelaide one can read early accounts of open grassy woodlands in the adjacent ranges, the Fleurieu Peninsula and the country to the north of the city that do not match the structure of the those denser shrubby mallee and forest remnant 'climax' communities that are present there now. A trip to the Art Gallery is quite the eye-opener in this regard - South Australians may want to compare the early paintings of the area surrounding the first falls at Morialta to its current 'natural' condition in the conservation park if they get the opportunity! And it is fascinating to contrast the works of, say, S T Gill, with the contemporary remnant landscape - Gill was an outstanding documenter of the very early colony, with a good naturalistic eye for the vegetation which is stands out in the generally turgid and mannered muddiness of the early colonial painters!
Anyway, that's enough from me. Thanks to all for the entertaining digression.
Aren't Messrs Hunt and Abbott nongs?
Some papers on fire affected ecosystems that David didn't mention in #35 provided for interested parties:
Restoration treatments improve seedling establishment in a degraded Mediterranean-type Eucalyptus ecosystem. Ruthrof et al. (2010) Australian Journal of Botany. 58 646-655
Abstract:"...Results indicated that created ashbeds enhance establishment for a range of species and reduce weed cover, with or without ripping ... The present study has shown that it is possible to re-establish local plant species in degraded woodlands through several techniques that mimic disturbance (e. g. fire)..."
Does pyrogenicity protect burning plants? Gagnon et al. (2010) Ecology. 91 3481-3486
Abstract: "Pyrogenic plants dominate many fire-prone ecosystems. Their prevalence suggests some advantage to their enhanced flammability ... We predict an advantage of enhanced flammability for plants whose fuels influence local fire characteristics and whose regenerative tissues or propagules are affected by local variation in fires... "
The effect of fire on birds of mulga woodland in arid central Australia. Leavesley et al. (2010) International Journal of Wildland Fire. 19 949-960
Abstract: "The principal ecosystem driver in arid Australia is unpredictable rainfall, but it is hypothesised that fire also plays an important role in determining the distribution of animals...The bird community in the burnt 2002 treatment was characterised by granivores, whereas that in the burnt 1976 and long-unburnt treatments was characterised by foliar insectivores. All species showed monotonic responses to time-since-fire (i.e. none were at significantly highest density in the burnt 1976 treatment). Fire in mulga woodland changed the vegetation structure and consequently also changed the composition of the bird communities."
Synergistic effects of water repellency and macropore flow on the hydraulic conductivity of a burned forest soil, south-east Australia. Nyman et al. (2010) Hydrological Processes 24 2871-2877.
Abstract: "Research shows that water repellency is a key hydraulic property that results in reduced infiltration rates in burned soils ... This study used 5 M ethanol and water in disc infiltrometers to quantify the role of macropore flow and water repellency on spatial and temporal infiltration patterns in a burned soil at plot (<10 m(2)) scale in a wet eucalypt forest in south-east Australia. In the first summer and winter after wildfire, an average of 70% and 60%, respectively, of the plot area was water repellent and did not contribute to infiltration."
Managing the matrix: decadal responses of eucalypt-dominated savanna to ambient fire regimes Russel-Smith et al. (2010) Ecological Applications. 20 1615-1632.
Abstract: "Much of our understanding of the response of savanna systems to fire disturbance relies on observations derived from manipulative fire plot studies...Using statistical modeling we assess the decadal effects of ambient fire regime parameters ... on 32 vegetation structure components and abundance of 21 tree and 16 grass species from 122 monitoring plots. ... Structural and species responses were variable but often substantial, notably resulting in stem recruitment and declines in juveniles, but only weakly explained by fire regime and habitat variables. Modeling of these observations under three realistic scenarios (increased fire severity under projected worsening climate change; modest and significant reductions in fire frequency to meet conservation criteria) indicates that all scenarios have positive and negative structural implications. Effecting significant regional fire regime change (e. g., reduction in frequency and size of severe fires) is demonstrably feasible, but it incurs risks and potentially some undesirable structural consequences.
Do Thinning and Burning Sites Revegetated after Bauxite Mining Improve Habitat for Terrestrial Vertebrates? Craig et al. (2010) Restoration Ecology. 18 300-310.
Abstract: "...Thinning and burning had no significant impact on the small mammal community, although Cercatetus concinnus was more abundant in rehabilitated sites. In contrast, thinning and burning significantly increased reptile abundance and species richness, with two species (Morethia obscura and Menetia greyii) only recorded in thinned and burned sites. We concluded that thinning and burning was a successful management option in revegetated mine pits in jarrah forests, particularly because reptile communities created by thinning and burning were more similar to those in unmined forest. Although published studies for comparison are few, we expect thinning and burning to have generally positive effects on reptile communities in forest ecosystems where fire is an important disturbance agent..."
The effect of a single burn event on the aquatic invertebrates in artesian springs. Munro et al. (2009) Austral Ecology 34 837-847.
Abstract: "...Artesian springs are a unique and threatened ecosystem, containing several rare and endemic species. Evidence suggests these wetlands were routinely burnt by indigenous Aboriginal people before European settlement over 100 years ago. Recently, burning has been suggested as a reinstated management tool to control the dominant reed Phragmites australis ... A single fire in late winter completely burnt the dominant vegetation, followed by recovery of Phragmites over the following 2 years. A single fire event did not deplete populations of endemic aquatic invertebrates in artesian springs, but probably did not substantially benefit these populations either. Isopods, amphipods, ostracods and three species of hydrobiid snail survived the fire event, and most had increased in number 1 month post fire but then returned to pre-burnt numbers by 1 year post fire. Morphospecies richness of all identified invertebrates increased over time in all springs, but did not differ appreciably between burnt and unburnt springs. If burning artesian springs is to be adopted as a management tool to suppress the growth of Phragmites australis, we conclude that the endemic aquatic invertebrates will survive a single burn event, without negative effect to their populations."
Frequent fire promotes diversity and cover of biological soil crusts in a derived temperate grassland O'Bryan et al. (2009) Oecologia 159 827-838.
Abstract: "...Consistent with expectations under IDH [intermediate disturbance hypothesis], cryptogam richness and abundance declined under no disturbance, likely due to competitive exclusion by vascular plants as well as high soil turnover by soil invertebrates beneath thick grass. Disturbance type was also significant, with burning enhancing richness and abundance more than mowing. Contrary to expectations, however, cryptogam richness increased most dramatically under our most frequent and recent (2 year) burning regime, even when changes in abundance were accounted for by rarefaction analysis. Thus, from the perspective of cryptogams, 2-year burning was not an adequately severe disturbance regime to reduce diversity, highlighting the difficulty associated with expression of disturbance gradients in the application of IDH..."
I 'spose it would be a bit too ironic to thank Hunt for triggering the magnificent distraction of this thread. But thanks to DH, BJ Foram, Chris, quoll et al. for engaging so bewitchingly. Slainte.
Thanks for the link to that Paul Krugman piece. It actually has bearing on Greg Hunt in terms of how inaccurate one can be. It is also an example of how the LNP has joined their cousins in the GOP in brazen denial.
BTW I emailed Julie Bishops Office yesterday regarding her misquoting Dr Joanne Simpson's piece as Tim pointed out on an earlier thread. I was moved to do this after streaming Monday nights Q&A in which she brazenly called the Prime Minister a liar over the carbon tax. That hyporcisy given the Article Bishop wrote roused me to write a long email saying why her misquoting of Dr Simpson didn't make her a liar. This morning, London time, I recieved an email back from one of her staffers thanking me for my email and saying Ms Bishop would get back to me.
Whoops, that should read:
That hypocrisy of Bishop given this article she wrote roused me to write a long email saying why her misquoting of Dr Simpson made Bishop a liar. This morning, London time, I recieved an email back from one of her staffers thanking me for my email and saying Ms Bishop would get back to me.
I really, really need to learn how to hit keys on keyboards properly.
I hope that your medical matters go well, and I would like to assure you that you are definitely not regarded as the last guest at the party; certainly not by me.
I'd actually typed a very long response earlier today on another computer, but I was stuck with M$Xplorer which 404'd my preview, and then gave me a blank comment field when I backed-up. Luverly.
So, a second attempt...
With respect to the aboriginal use of fire, I took pains to separate such use as a cause of evolution of fire-resistance, from use to modify habitat to a state conducive for human use. At least, I thought I did - if there is any confusion, rest assured that I am not attributing primarily to humans the instigation of the development of any fire adaptation in plants. Having said that, to the extent that humans are now consistently firing the bush and thus applying a pressure upon fitness, we may well be furthering the evolution of resistance to fire.
On the matter of the Hawkesbury regrowth, my point was to demonstrate that some species were able to regenerate after the hottest fires imaginable for the particular vegetation associations that were burned. Many plant species would not thus regenerate, and to the extent that these native species did surely indicates, in part, that there is an adaptation to fire. If the adaptation is assumed to be a response to, say, drought, one would need to explain (amongst other things) why many solely arid-region species would not survive such a conflagration, where the Hawkesbury species did.
And yes, many plants that regenerate after such an extraordinary fire often do not survive as viable plants for very long. This is not surprising, as this was a fire that reached close to maximum possible heat intensity.
This does not mean however that fire-resistant species cannot survive less-severe blazes. In my fieldwork one of my conspicuous landmarks at one site was a huge eucalypt whose lower trunk was burned through to form an arch almost 2 metres high, at least a metre wide, and about 75 centimetres from one inner face to the other. The tree must have been well over a metre wide when it was burned, and it was spectacularly burned through the base - the remaining charcoal on the inner surfaces of the hollow was several centimetres thick. The tree had grown scar tissue around the edges of the cavity, rolling from the outside back toward the centre to form new columns of live wood that were as thick as a man's arm at each edge.
This tree had quite obviously survived a big fire, and gone on to flourish for at least several decades after. I'm sure that many, many similar examples could be cited, sufficient to demonstrate that some Australian flora species do regularly persist successfully after significant fires, where other species simply would not.
In my previous draft I'd also included a number literature references pertaining to fire resistance, but as Chris S. has since posted several abstracts himself I'll not go back to typing more.
Another point that I'd spent quite a lot of time on related to the character of growth of Cassinia aculeata, of which I have several acres, on the drier cleared areas of my property. It's a classic coloniser: the largest ones I have manage to reach 5 metres, but most are a metre or two shorter, and they only live a decade or two before becoming so scrappy and decrepit that they simply split to pieces in the wind or just fall over. Quite simply,they don't bother trying to live long to prosper - they just get their seed out there and that's it.
They have two characteristics though that are classic of the examples used to illustrate fire resistance - they go up like Roman candles at the merest spark (and I mean whoosh!), and the seedlings pop up like crazy after a fire, much more than after a drought. Perhaps these features are not explicitly the pyrogenicity (to which one of Chris S.'s abstracts referred) and the pyrophilia that many claim distinguishes fire-resistant flora, but if not, what are they, and why do they characterise other adaptations over (or to the exclusion of) fire resistance?
In my first draft I went into far greater detail both in terms of Cassinia growth habit, and in referencing, but I simply can't be bothered to try to retype it all again. I'd be very interested though to get your thoughts on what these adaptations are, if not to fire.
Oh, and Greg Hunt is still a numpty.
More medical stuff today I'm afraid so this has to be quick. Thanks to all (except Mr Murray) for the thought you have put into your replies. You still need to examine your assumptions I'm afraid. Much of this stuff looks like fire adaptation only when seen through the lens of a belief that there is such a thing as fire adaptation. Similarly Aboriginal use of fire only seems important if you have been led to believe it is. And on that note, you have to be very careful in interpreting both early colonial accounts and art in terms of their relevance to effects of Aboriginal fire on landscapes. Things ain't always what they seem.
Bernard and Chris are both essentially making the same point - that there is ecological succession after fire. There is always ecological succession after any disturbance - some species (eg Cassinia - I have it growing in almost bare rock on my bulldozer-scraped drive Bernard) come in very quickly with a lot of seed and fast growth, others are much slower to colonise. Some may take 100 years to come back if they are both slow-growing and slow moving.
Chris your Phragmites story is a good illustration - "we conclude that the endemic aquatic invertebrates will survive a single burn event, without negative effect to their populations." Well, I'm sure that is true, but what was being tested was that Aborigines regularly burnt the swamps. If any Australian habitat had been regularly bunt there would have been massive extinctions of the smaller vertebrates, invertebrates, and the smaller flowering plants and shrubs.
Sorry, I have to go now and think about other things. Perhaps Tim might like to have another thread at some later date when I am back in the land of the functional.
Chris s and Bernard J have provided plenty of intriguing reference material for the forthcoming 'The Burning Question' conference! Or thread...
I know many in the landcare/bushcare/reveg community view the whole issue of carbon sequestration, whether in the soil or in the form of standing vegetation, with considerable apprehension. 'All we need's a million hectares - don't you worry about that' combined with hand-waving references to 'Forestry Measures' is just the kind of thing that has me very worried indeed, and not just about any efficacy in actually sequestering carbon!
Once we embrace the concept of (re)shaping Australia's landscape - chiefly in order to facilitate maintaining Business as Usual economics - via initially making carbon sequestration claims that would appear to border on the magical, what happens when it turns out that the CSIRO was right all along (and let's face it, it probably will)? We've lost time, certainly (this was probably more-or-less the intention) and gained little, but all true fanatics know that if something isn't working you really just need to do more of it and harder! Particularly where otherwise we might revert to making modifications to the economy, the one true 'natural' given that must be preserved.
I'm quite the admirer of many landscapes and land uses that Abbott and co. might well be happy to assign as 'unproductive', and ripe for 'enhancement'. Shades of the scary engineering inherent in some grand visions of 'making the deserts bloom,' where one hectare is held to be much the same as another, and all must deliver...
OT..just heard Lindzen on MTR radio, claiming that Arctic ice is variable and not a cap, as it is not land based, when asked about Polar ice cap melting, avoiding the question.
Hilariously he stated everybody accepts doubling CO2 on it's own causes 1 degC rise, and the host accepted that. Bizarre the anti-science crew can fundamentally contradict themselves within the space of an interview and not even blink. Is that the definition of a fundamentalist? somebody who can fundamentally contradict a proposition and still accept the proposition.
Seems the deniers are starting to move the goal posts.
OT...does Joe Bastardi really think there are Clouds in space?
Again, I hope that your medical matters go smoothly.
Bernard and Chris are both essentially making the same point - that there is ecological succession after fire. There is always ecological succession after any disturbance...
Yes, there is, and this was a part of my point.
In fact, I would posit that the commencement of a succession after a disturbance is a niche in time, as much as there are niches in space and/or relative to other physical resources. To the extent that such a temporal niche might be extended in duration, or fascilitated to occur again, species that utilise such niches stand to benefit. Plants are unable to induce severe storms, or landlsides, or the falling-over of mature light-blocking trees, but why should pyrogenicity not evolve, even if the volatile oils involved initially had a purpose in herbivory discouragement and/or disease resistance? Nature is replete with examples of adaptations that were co-opted from other, original functions.
And such an adaptation would favour plants that utilise the temporally temporary (sorry, couldn't resist) niches that occur after fire, thereby increasing their ecological/evolutionary fitness.
I'm pleased that you mentioned the response of Cassinia after bulldozing. Along one of my boundaries I have a driveway that leads to my neighbour's properties. As a result of the extreme steepness of the land the drive is eroded by rain, and requires reconstruction by a dozer every few years. After each new re-surfacing Cassinia occasionally sprouts up in the turned clay on the sides of the drive.
However, if the grass/herbaceous verge is burned the Cassinia regrows to a far greater extent. Is this simply a transference of an adaptation from an original, different causative pressure, that serendipitously causes a better response after fire, or has the species actually evolved the facility to maximise its response specifically to fire? Most interestingly, how would one demonstrate experimentally that fire is not positively adapted to?
I will reiterate my previous comment that I agree with you that the Australian bush is not naturally adapted to the frequency of fire to which is is exposed in the presence of humans. European firing practices (and, I suspect, aboriginal ones) certainly simplify ecosystem diversity by leading to local extinction of fire-sensitive species and associations. I am greatly concerned by this, as I am certain that it is a creeping process more than an explicit one, but one that is greatly boosted by the occasions of arson-caused wildfire and the subsequent knee-jerk community response to reduce 'fuel' load in the years after.
And yet I still beg to differ with you on the matter of pyrogenicity. Repeated burning will surely select for plants that quickly recolonise after a fire, and because many such plants are simultaneously producers of high amount of volatile oils, regular and frequent 'preventative' firing will surely change a plant community association to one that is both pyrogenic - and pyrophilic? [Peterson](http://www.geog.mcgill.ca/faculty/peterson/PDF-myfiles/contagion.pdf) certainly thinks so, and [Close et al](http://www.personal.psu.edu/faculty/a/g/agl/forest%20decline%20fire.pdf) present work that supports the idea, and there are many experimental studies that demonstrate this: I'm sure that you are aware of them so I won't fill the post with links.
In my local area I can point to data that supports this idea. When my childrens' mother did a field study on the effect of fire on local plant associations for her environmental managament diploma, I trawled through the data her class collected to see what was happening.
In the local area at least, there appears to be a dynamic tension between Eucalyptus globulus and Eucalyptus pulchella on the one hand, and Eucalyptus viminalis on the other. With an increasing frequency of hot burns, the numbers of E. globulus and E. pulchella per unit area increase, and the number of E. viminalis decreases. Conversely, with a decreasing frequency of hot burns, the numbers of E. globulus and E. pulchella also decrease, and the number of E. viminalis increases. Any parsimonious explanation would surely indicate that E. globulus and E. pulchella are more resistant to fire compared to (and at the expense of) E. viminalis: the question here is whether they are better adapted to fire compared to E. viminalis?
This has profound implications for fire regime management in this state, as it is the only place in the world where the endangered 40 spotted pardalote occurs. And as the pardalote feeds only on insects and sap secretions found on E. viminalis, careful control of fire regime is critical to the bird's survival.
And what of plants such as Telopea speciosissima, a 'pyrogenic flowering' species? Its growth, flowering and seed set, as with similar pyrophilic species, are strongly tied to the requirement for a fire first - do you propose an alternative explanation for this pattern of growth? If so, I'd be very interested in hearing it.
I will conclude by saying that I am greatly enjoying this discussion. It is certainly making me think about the subject, although I am yet to be convinced that the evidence for plant pyrogenicity and pyrophilia is more parsimoniously explained by non-fire ecological pressures.
I am greatly enjoying this discussion. It is certainly making me think about the subject
Me too. Thanks to all who've contributed, never mind the OT - it's better than reading the usual endless OT rants from the climate septics. Got some refs on bushfire on the shelves here that I'll have a read of when I get time, but I'd be interested in David Horton's view on papers by Profs Ross Bradstock and Rob Whelan on fire adaptations by Australian plant taxa.
...I'd be interested in David Horton's view on papers by Profs Ross Bradstock and Rob Whelan on fire adaptations by Australian plant taxa.
Now there are two big names in fire ecology.
I suspect that David Horton's book might contain responses to their work, and I am now minded to track down a copy.
Even if David can't change my mind on the subject, I am very much appreciating the different perspective this thread has given me on several matters.
One thing that I'm not really raising in all of this, and that is quite possibly being missed by readers here, is how Greg Hunt's fantasies of significant carbon sequestration in soil is a thermodynamic joke. I'm hoping that a some point in proceedings our diversion will head into that territory, and bring together matters of soil ecology and carbon physical chemistry.
David, I have to take issue with this statement: "If any Australian habitat had been regularly bunt there would have been massive extinctions of the smaller vertebrates, invertebrates, and the smaller flowering plants and shrubs."
I vividly recall following a fire in the Zambian dambos and finding millipedes wandering around seemingly unharmed on still-warm ground and wondering how many invertebrates were able to avoid fires in the same way - many of course can fly away, or even over the fire-front but others are obviously unable to, what happens to them?
An obvious answer - if you can't go around or over, you go under and it is clear that many flightless invertebrates are well able to burrow into the soil, and this is likely what my millipedes had done. [Abbot](http://www.publish.csiro.au/?paper=SR9840463) looked at the soil fauna of burnt & unburnt plots and found that "Ten taxa ... showed no significant difference in density between plots ... (earthworms, spiders, Isopoda, termites, earwigs, crickets, beetle larvae & adults, fly larvae and ants. Millipedes occurred at significantly greater densities in the burnt plot, and centipedes, silverfish and cockroaches at significantly lower densities in the burnt plot."
There is also the presence of various fire refugia - something that, for example [Brennan et al.](http://onlinelibrary.wiley.com/doi/10.1111/j.1442-9993.2010.02127.x/abs…) have looked at recently.
That covers invertebrates I'll look at small vertebrates in a second post in order to avoid the spam filter...
Small mammals that burrow tend not to stray far from them thus providing a refugia from fire should they remain deep enough (again, going back to my Zambian experince even medium size mammals (warthogs) would sit out the fire underground emerging unharmed after the fire front had passed).
In Australia [Banks et al.](http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0706.2010.18765.x/abs…) have found that in situ survival is the basis for recovery of two species of small mammal (agile antechinus and bush rat). On the other hand [Kelly et al](http://www.publish.csiro.au/?paper=WR10016) found that "species richness of native small mammals was positively associated with unburnt vegetation, although some species showed no clear response to wildfire" and that "The only species positively associated with recently burnt vegetation [was] the introduced house mouse". So the jury may still be out on this one.
I'll finish with the following Abstract from Bradstock (2008) International Journal of Wildland Fire. 17 809-822
Abstract: "Large fires coincident with drought occurred in south-eastern Australia during 2001â2007. Perceptions of large, intense fires as being ecologically âdisastrousâ are common. These are summarised by four hypotheses characterising large fires as: (i) homogenous in extent and intensity; (ii) causing large-scale extinction due to perceived lack of survival and regeneration capacity among biota; (iii) degrading due to erosion and related edaphic effects; (iv) unnatural, as a consequence of contemporary land management. These hypotheses are examined using available evidence and shown to inadequately account for effects of large fires on biodiversity. Large fires do not burn homogeneously, though they may produce intensely burnt patches and areas. The bulk of biota are resilient through a variety of in situ persistence mechanisms that are reinforced by landscape factors. Severe erosive episodes following fire tend to be local and uncertain rather than global and inevitable. Redistribution of soil and nutrients may reinforce habitat variation in some cases. Signals of fire are highly variable over prehistoric and historic eras, and, in some cases, contemporary and pre-European signal levels are equivalent. The most important effects of large fires in these diverse ecological communities and landscapes stem from their recurrence rate. Adaptive management of fire regimes rather than fire events is required, based on an understanding of risks posed by particular regimes to biota."
What you are forgetting is that fire can be caused by (a) invasive plants that are native to regions where fire is a persistent threat, and (b) that, once established, these plants enhance fire risk, forever changing the dynamics and stability of the systems in which they become established. Plants like Eurasian cheatgrass (Bromus tectorum) and Melaleuca quinquenervia are well adapted to fire regimes and have been introduced into biomes in the United States that are not used to fire (the western US and Florida respectively). These plants thrive in burnt habitats and soon exclude non-adapted native fauna; the result is a simplified community with impoverished diversity where the invasive plants quickly become dominant.
In tropical biomes, fire creates dry micro-climates that make the understory more susceptible to future fires. In many cases the effects are irreversible.
The bottom line is that fire is an omnipresent threat to many habitats that are not naturally associated with fire and which have been significantly altered by a suite of human processes: destruction of understory, fragmentation, the introduction of fire-adapted invasives. Where plants are co-evolved with regular fire regimes, plants and their communities become well adpated to its persistent risk. But in wet biomes, this is strictly not true. The increase in fire because of Melaleuca in Florida has profound implications for the survival of both vertebrate and invertebrate communities in the state associated with native vegetation: both from the loss of native species to Melaleuca and because of fire. No ifs of buts.
Jeff, I wouldn't say I was forgetting any of those caveats. I appreciate my experience of fire-prone ecosystems is largely restricted to the African dambos & savannah but I was specifically responding to David's points that (and I paraphrase here) a) there is no such thing as fire-adaption in nature and b) that regular burnings will necessarily result in massive extinctions of certain taxa. I don't believe either of those assertions are true in the wider context of dry-land ecosystems, or the specific context of the Australian systems under discussion.
That fire is "an omnipresent threat to many habitats that are not naturally associated with fire" I don't dispute in the slightest, however to focus on these to the exclusion of those habitats that are naturally associated with fire kinda misses the point. Of course there may well be discussion to be had on whether Australian habitats are fire-associated and to what extent. From my reading there is enough evidence of adaptation to demonstrate that certain ecosystems have a long history of fire disruption.
"There is no evidence that Aborigines increased the amount of fire in Australia, or that their use of fire had a particular purpose (other than for hunting), or that it had any effects on vegetation patterns"
Sorry but that is utter rubbish. Hundreds of articles can be found in the peer reviewed that make precisely these points. Philip Moore sums up the findings quite nicely in his handy book "A Guide to Plants of Inland Australia".
"During [Australia's] final cold dry phase, rainforests in the east and north became more restricted and disjunct than ever before, while cold tolerant plants such as daisies and grasses thrived. When conditions improved, some rainforests did not regain their former territory. Neither were they replaced by less complex types of closed forest. Evidence from several sites in the east indicates that for the first time after 20 or so glacial episodes they were replaced by eucalypt dominated forests and woodland. The only new factor on the occasion was the presence of humans." (p. 32)
Even the most environmentally ignorant of Australians is generally aware of the active fire management required to maintain certain ecosystems, such as the button grass plains that cover one-seventh of Tasmania, and which are a legacy of indigenous burning.
Certain Australian native animal species have even been labelled fire-specialists by ecologists in the peer reviewed literature including the lizards Ctenotus atlas, Amphibolurus norrisiand and Nephrurus stellatus, see for example Smith, A.L et al, 2011. Primers for novel microsatellite markers in "fire-specialist" lizards (Amphibolurus norrisi, Ctenotus atlas and Nephrurus stellatus) and their performance across multiple populations in Conservation Genetics Resources.
I must have at least two or three hundred peer reviewed papers on my shelves alone that detail flora and fauna fire adaption and the role of pre-colonial indigenous fire regimes in shaping the nature and distribution of Australia biota.
That entire argument of using incentives for farmers to sequester carbon in soil is flawed at so many levels. For starters farmers are struggling to make their businesses viable when things are working in their favour, so thinking that they have the extra time and resources to gather all waste vegetable matter on their farmland for conversion to biochar, by what process? with what efficiency? and then disperse this evenly back over their land and plow it in so that it cannot be consumed by bush fire, and all financed by an "incentive", is a stretch of credulity by a factor of more than a hundred square. And then there is the variable of drought. This Coalition bluff is just a continuation of typical conservative cane toad science.
Hi, am back in action for a bit (the saga has been unfolding on the main part of my blog http://davidhortonsblog.com/ if you are interested), and there has been a lot of action while I have been gone on poor Tim's hijacked thread!
Can I start by saying to John that 35 years ago when I began research into fire (as part of my over-arching research topic of Aboriginal interaction with the environment) I thought that the whole thing was cut and dried - plants and animals adapted to fire, extensive Aboriginal use of fire modifying past environments - all seemed perfectly logical and well-supported. The more I worked on the topic the more the evidence began to unravel, the less valid the observations and hypotheses, until I found myself at the other end of the spectrum of theory. I wasn't totally alone in that journey, others were drawing similar conclusions, and others have since independently found their own way there. But three things that prevented more doing so was that the media loved this dramatic idea; that the people promoting the use of fire to "manage" national parks found support for their demands; and that many ecologists, assuming the archaeology/anthropology was correct, and many archaeologists, assuming the ecology was correct, neither side with an ability to independently assess the other, began working on the basis that the hypotheses about fire use and adaptation were correct. It became a self-fulfilling hypothesis, and those are very hard to break.
And to come back to the crux of the matters raised by Bernard and Chris. The question isn't whether some species can survive a fire and recover quickly, of course they can, although the proportion that do would be less than people think. Only the obviously visible species tend to be considered, and there is a lot more to an ecosystem than that. But yes, fires burn unevenly, there will be pockets of less burnt, even mostly unburnt habitat from which species can recolonise. The whole thing is no different to the destruction from a cyclone. That isn't the issue, the issue is whether they can survive frequent fires, the kind that both Aboriginal "fire-stick farming", and "prescribed burning" regimes demand, and the answer is, no they can't.
The other major issue is that if you say species/habitats are "adapted to fire" it wasn't much of a step for the "fire managers" to pretend that this meant in turn that they "needed" fire. This was supported by the proposition that since Aborigines were meant to have burnt regularly and extensively in the past, we should start doing that quite happily again - nothing could go wrong because we were just doing what the forests needed, and doing what had been done for "50,000 years". They were powerful pseudo-scientific proposals happily melding with what the guy in the country pub believed, what the right wing media believed, and therefore what populist politicians believed. It has been a potent brew and a lot of damage is being done.
I can only repeat, being adapted to recover after damage is of course a feature of ecosystems and individual plants and animals, if it wasn't the Earth would have been denuded of life long ago. But being able to do this, including recover after a fire, gradually and haltingly, doesn't mean we should think they are adapted to fire, and even less that they "need" fire. And because some animals (notoriously the introduced house mouse) can move in quickly in to colonise bare ground, and that some plant species (again, notoriously, introduced weeds) can do the same, thus setting in train a succession that will rebuild, more or less accurately, over more or less numbers of years, the habitats that were present before a fire, tells us nothing in support of the idea of frequently burning such areas.
Excellent and informative, thanks.
"I can only repeat, being adapted to recover after damage ..."
David, the whole idea of fire constituting "damage" is an anthropogenic overlay on a natural process for which concepts like damage are meaningless. It is the same with floods, with some species like Eucalyptus largiflorens (Black box) requiring infrequent flooding in order to regenerate.
You seem to be confusing the Australian environment with an English rose garden.
John, in what possible way could fire not be seen as "damage"?
David, you raise some good points, particularly on the role of invasive plants in the Australian ecology. However the following remains (to me) an unsupported assertion:
"The other major issue is that if you say species/habitats are "adapted to fire" it wasn't much of a step for the "fire managers" to pretend that this meant in turn that they "needed" fire."
There are certain plants in the African biota (and forgive me, not being a botanist I can't recall their names offhand) that will only flower after a fire event. Surely these are the definition of species that 'need' fire?
I'm also unsure after the provision of the link to Abbott's findings in #65 that you can state "Only the obviously visible species tend to be considered, and there is a lot more to an ecosystem than that" without reference.
"John, in what possible way could fire not be seen as "damage"?"
perturbation is probably a better word because "damage" has negative connotations. Let me quote from "Temperate Woodland Conservation and Management" (20110) Lindemayer, D. (eds) et al. ch 23 "Woodland Biodiversity Conservation: Basket Case Or Battleground? Insights From The Mallee", Dricoll, Don:
"Although we have found little evidence that ground dwelling beetles are effected by fire, fire has a strong effect on most other groups in mallee woodlands. A single fire provides open habitat that is favoured by several reptile and bird species and stimulates germination of plant species that may have been present in the community only as soil-stored seed .... [Callitris] ... can decline if the fire interval is too long because plants senesce and canopy-stored seed declines ..." p.194
The same book contains dozens of examples by different chapter authors of the critical role fire plays in maintaining biodiversity in Australian temperate woodlands. Each makes the point that fire is necessary and that both too little and too much fire harm biodiversity, with reference to the peer reviewed literature.
It is apparent to me that you are unfamiliar with the scientific literature.
Chris "will only flower after a fire event" I think is better translated as "will only flower instantly after a fire event", and I don't think that dumping all your seeds on the ground after a fire event (which has no necessary link to a following rain event; and which means that even if they do all germinate also means that they can all be wiped out by another fire event following before the new plants are old enough to set seed) would be a good adaptation, or one favoured by natural selection. Whereas holding on to your seeds for long periods, and only releasing them gradually over the course of a long drought would ensure survival of at least some individuals (a case of not putting all your eggs in one basket).
I don't think I was dismissing #65, which itself points out that while some tough (and visible) species were abundant, others less so were not. The media coverage of fire always focuses on the Eucalypt sprouting ("a miracle") from the bark, and kangaroos coming in a week or so later to nibble whatever fresh shoots are available. In neither of these cases even is any reference made to tree species that didn't survive as individuals (or whose seed bank in the ground was destroyed), nor any reference to the dead kangaroos who didn't escape. And I have never seen any mention of the smaller vertebrates or the smaller plants, let alone the fungi and bacteria and soil invertebrates, let alone any consideration of the destruction of leaf litter, hollow logs, soil organic matter in top layers, boggy and swampy areas, and so on.
Now of course many ecological studies do take some or all of this into account. But while I know there are studies that show how some organisms survive a single fire, even a fierce fire in improbable circumstances, I don't know of any studies that show an area can be regularly burnt without severely affecting the lower parts of the pyramid of organisms, or the carbon and water cycles, without which a forest (say) can't survive in a healthy form. And that is without mentioning the almost inevitable favouring of weed and pest species, and as someone says above, the favouring of such species often results in more fire, setting up a vicious downward cycle (as abundant annual weeds dry out, rabbits cause soil disturbance).
... an 'anthropogenic overlay' resembling that anthropogenic construct language itself without which even natural process disappears.
John I am really not sure what the nature of our disagreement is. Fire damages (like a flood or a cyclone) by physically damaging many existing organisms, and by potentially at least reducing their chance of reproducing in the near future. The fact that some organisms can reproduce and or survive as individuals doesn't contradict this definition. The fact that some elements of an ecosystem can recover more readily, even be favoured by circumstances, doesn't contradict this either. I simply don't accept this as being "adaptation" in any meaningful sense of the word, and while it may make us less despairing of the future of, say, a forest, after a fire (or a cyclone) goes through it, that doesn't mean that we should be welcoming frequent fires (or cyclones). "Perturb" any ecosystem too much and the unintended consequences will be major ones.
"I don't know of any studies that show an area can be regularly burnt without severely affecting the lower parts of the pyramid of organisms"
Geez David, I gave you one in #53 (O'Bryan et al. Frequent fire promotes diversity and cover of biological soil crusts in a derived temperate grassland) Though I suppose a promotion of diversity is a severe effect ;-)
Here's some more for your consideration:
Defining grassland fire events and the response of perennial plants to annual fire in temperate grasslands of south-eastern Australia. Morgan (1999) Plant Ecology. 144 127-144
Abstract: "... Annual burning permits high perennial species richness and high numbers of individual perennial plants to co-exist at the small-scale. Seasonal plant density maxima peaked in spring, 6-8 months after fire, and the number of plants in a species' population each year following fire depended on their seasonal response more than their direct fire response. The direction and magnitude of population change from one year to the next was species and site specific and did not correlate with life form or a plant's ability for vegetative spread ... Seed that has made its way into the soil is completely protected from the direct effects of fire and hence, occasional post-fire seedling recruitment may be possible for all species. Maintaining annual burning in grasslands as a management regime is unlikely to lead to a decline in richness and plant density in the short-term. Rather, delayed burning (i.e., > 3 year intervals), and the impact that this may have on interval dependent processes such as above-ground competition, are predicted to have more substantial long-term effects on the small-scale dynamic of this community."
Fire frequency regulates tussock grass composition, structure and resilience in endangered temperate woodlands Prober et al. (2007) Austral Ecology. 32 808-824
Abstract: "...We established replicated burning, mowing and (non-livestock) grazing regimes in two contrasting grassy woodland remnants in south-eastern Australia, and monitored the dynamics and resilience of the matrix-forming tussock grasses, Poa sieberiana (Poa) and Themeda australis (Themeda), over 12 years...Introduction of frequent burning to a Poa-dominated understorey in a rarely burnt woodland enhanced dominance by Themeda, and conversely, reduced fire frequency in a frequently burnt Themeda grassland substantially increased Poa abundance. Burning was potentially detrimental in the Poa-dominated woodland, but sward resilience (recovery after the 2002 burn) increased as Themeda increased with repeated burning...We conclude that functional complementarity associated with mixed dominants enhances resilience to variable disturbance regimes, and that below certain thresholds of abundance of each dominant, this resilience declines. Conservation management of Themeda-Poa ecosystems should thus aim to maintain an effective balance of these dominants."
Effectiveness of repeated autumn and spring fires for understorey restoration in weed-invaded temperate eucalypt woodlands. Prober et al. (2009) Applied Vegetation Science. 12 440-450
Abstract: "In a replicated, 5-year experimental trial, the effects of repeated spring or autumn burning were evaluated for native and exotic plants in a representative, degraded Eucalyptus tereticornis grassy woodland... The dominant native grass Austrodanthonia caespitosa and native forbs were resilient to repeated fires, and target exotic annuals and perennials were suppressed differentially by autumn and spring fires. Exotic annuals were also suppressed by drought, reducing the overall treatment effects but indicating important opportunities for restoration. The initially sparse exotic geophyte Romulea rosea increased in cover with fire and the impact of this species on native forbs requires further investigation. There was minimal increase in diversity of subsidiary natives with fire, probably owing to lack of propagules.
While fire is often considered to increase ecosystem invasibility, our study showed that strategic use of fire, informed by the relative responses of available native and exotic taxa, is potentially an effective step towards restoration of weed-invaded temperate eucalypt woodlands."
And you may find the references of the following study of interest too: The diversity-disturbance relationship: Is it generally strong and peaked? Mackie & Currie (2001) Ecology. 82 3479-3492
Abstract: "The contemporary literature accepts that disturbance strongly influences patterns of species diversity, and that the relationship is peaked, with a maximum at intermediate levels of disturbance. We tested this hypothesis using a compilation of published species diversity-disturbance relationships that were gleaned from a literature search of papers published from 1985 through 1996 and from references therein."
David I should also note that your writings here are becoming peppered with language like "I don't think that" or "I simply don't accept". These are starting to look like arguments from incredulity.
You've written a book on this subject which should mean you've done some research. Time to back up these statements with some empirical evidence please - Bernard, John & myself have provided plenty of references - where are yours?
Sigh. I've just given you evidence that Callitris species in mallee woodlands NEED fire otherwise that cannot successfully regenerate. Without an appropriate fire regime they will either become extinct or be reduced to insignificant. You obviously aren't interested in the evidence.
Chris I provided some very recent references earlier too (one rejecting the "Australian plants are adapted to fire" meme ["Our review of the literature suggests that traits commonly accepted as âfire adaptationsâ of Mediterranean-climate plants have more complex origins and that environmental factors other than frequent fire have promoted their evolution" - one of the authors, Dixon, incidentally, being the chap who did the original research on smoke stimulating seed germination], another effectively putting to bed the Aboriginal fire regimes were more frequent in the past suggestion ["There is no distinct change in fire regime corresponding to the arrival of humans in Australia at 50 - 10 ka and no correlation between
archaeological evidence of increased human activity during the past 40 ka and the history of biomass burning. However, changes in biomass burning in the last 200 years may have been exacerbated or influenced by humans"], the other warning about the effects of frequent burning on habitat). An argument from "incredulity" is no bad thing in this field. As the case with John, I am not sure where the examples you provide are some kind of refutation of my argument. I have no doubt at all that you can manipulate habitats, change species balance, introduce weed species, prevent later successional changes, etc, by the use of fire. Just as you could by use of a lawnmower, or by regular tree harvesting, or by frequent storms or floods. You can, as the Themeda-Poa example suggests, even make a choice as to what you want to see dominant in a particular area. But we are now a long way away from the idea that Australian organisms and ecosystems are either adapted to or need fire. And even further from the proposals that bush needs to be managed by the use of prescribed burning every year or two or three (with none of the fine control or concern that your research examples use). And even further from the idea that the "fact" that Australian ecosystems are adapted to fire means that there would always have been a lot of charcoal in the ground and therefore oodles of time for organisms to evolve to break it down, thus throwing into doubt the best laid plans of mice and Greg Hunt, which is where we began an eternity ago.
I think it is time that Tim read the Riot Act to us all and told us to go to our own homes! We can't keep throwing volleys of references at each other. All I was really trying to do here was point out that the current orthodoxy about fire in Australia is not unanimously accepted, that therefore further hypotheses based on it may not be on the surest of footings, and that people might want to look a bit more critically at action plans for managing the Australian environment by use of fire. Maybe I am wrong, but I am fearful that if I am not there is a great deal of damage being done to Australian habitats (especially forests) on the basis of less than rock solid theory - we need to keep asking questions, and I hope I have succeeded in helping stimulate a very good discussion here along those lines.
"Specifically, why have bill's Banksias not adapted to fire at all?"
I suspect David's rebut was about the idea that fire adapted fora adapted to fire so that it would break down carbon, not that they'd adapted to fire.
Being germinated by fire doesn't mean you eat pure carbon. It just means that you won't germinate until a bushfire has burnt you (and everything else, so you've got a clear run at growing up).
David and Chris,
Speaking as an ecologist, you are both correct - and wrong. The bottom lines are *context* and *trait-dependency*. To take this further it is these parameters within the realm of frequency-dependent selection. Thus, if fire is a recurrent event within an ecosystem or biome, then its resident biota would not only have adapted to regular fire regimes but would probably use fire to their own advantage in terms of reproduction and dispersal. At the other end of the continuum are systems where fire is not a regular event. In this situation, the resident biota would not be selected to respond adaptively to it, and many would be seriously affected by a fire event.
The context I am referring to is regularity and predictability of a disturbance (e.g. fire) as well as certain structural characteristics of the habitat, and the traits I am referring to are behavioural, physiological or morphological adaptations of the local biota to it. Of course, some of the contexts may change e.g. changes in rainfall regimes, habitat fragmentation loss of understory, microclimate etc., as well as the arrival of novel invaders with unique traits (see my post yesterday). But if a system is well adapted to fire it will suffer if for some reason there is no fire to generate conditions favoring the adapted biota; alternatively, if a system is not adapted to fire, then a fire event may be catastrophic at a local scale at least.
Therefore, it is nbot possible to extrapolate generalizations on the pros and cons of fire on the rules governing the assemblyt and functioning of ecosystems. Consequently, we have to examine every system individually, and focus on events that often occur at local scales.
BTW - I've worked out that to achieve the Libs proposed 85 million tonnes by 2020, by renewing soil carbon, would require between 10% and 70% of all agricultural land in Australia to be continually sequestering carbon for each of the next nine years - and retaining it thereafter forever! It can't be done as a once off - the numbers don't work. So it has to be accumulated each year.
The 10% figure assumes 2T/hectare/year retained carbon over each of the next nine years. Quite unlikely I'd have thought.
The numbers assume a build up each year - no droughts or reduction in carbon through other means. Equally unlikely.
The cost of monitoring and auditing would be astronomical. There is no indication in the policy paper of who would do it or who would pay.
And it's unlikely the world will ever accept this as a legitimate carbon reduction mechanism in any case.
I can see I'm a bit late to the argument but Sou's comment caught my eye. Not only do you need to sequester carbon, but for biochar you need biomass to create the biochar. Maybe I've got it wrong but I'm thinking little charcoal kilns converting biomass into biochar. How would this be done?