Aborigines managed much of the Australian landscape with fire. This management strategy favoured fire tolerant and fire resistant species – perhaps why gum trees dominate so much of the Australian landscape. But river red gums, Eucalyptus camaldulensis ssp., unlike most gum trees, are not particularly fire tolerant.
A boat on the Murray River in the Barmah Forest. Photograph taken last Tuesday.*
The timber cutters and cattlemen who live and work along the middle Murray (river) have gone to great lengths to keep fuel-loads in red gum forests low through controlled grazing and the collection of firewood. This, combined with a network of rural fire fighting brigades, has made it possible to stomp out fires started from lightening strikes or camp fires.
This may explain why some foresters and aboriginal elders call river red gums ‘white fellas’ weed’ and why areas which were once open woodland are now covered in dense red gum forests including at Barmah.
This area in Barmah Forest was once known as Duck Hole Plains
But the situation is changing. The Victorian Environmental Assessment Council (VEAC) wants more wood and grass on the forest floor apparently to increase biodiversity. This means higher fuel loads and according to some white fellas** the forests will ultimately be severely degraded by uncontrolled and uncontrollable feral fires.
A wildfire in the Barmah Forest, in an area known as Top Island, burnt out 800 hectares last October.
Burnt forest at Top Island in October 2006, photograph taken Tuesday November 6, 2007.
Old habitat trees are apparently the first to go when a hot wildfire burns through red gum forest. Last week the Barmah woodcutters showed me how the old trees ‘burnt like chimneys’ from the inside – out.
Parts of ‘Top Island’ look like they are regenerating. But I’m told that the green coppice growth will eventually fall off – that these fire-damaged trees will never develop as habitat trees. Habitat trees have hollows for wildlife.
Coppice and a burnt-out old habitat tree.
Where the forest has been completely burnt, for example after the sand-spit fire of the late 1960s, and where there has been no management, the red gum regrowth can be very dense.
Regrowth from the 1968 Sand-spit fire, Photograph taken November 6, 2007.
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* All the photographs in this blog post were taken in Barmah forest last Tuesday – on Melbourne cup day.
** I use the term ‘white fellas’ to refer to the guardians of traditional European knowledge in the Barmah forest.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Its a Saturday night & I’ve had a few reds so while I have been an interested on & off reader of this blog for a number of years I will finally offer a comment.
Yes, of course Australian vegetation evolved with fire & this was reinforced by the management imposed by the original indigenous people. Two quotes come to mind “Aborigines lit fires any time it wasn’t raining” & “the indigenous people managed the country in 3 ways – by burning it – frequently, regularly & often”. The eucalypts responded to this by being reliable & prodigious seed producers while also developing very effective mechanisms for vegetative reproduction if the root system was disturbed. But once the seed dropped out of its protective capsule to the ground it was ‘naked’ & short lived & the emerging seedling was very susceptible to ubiquitous ‘root rot fungi’. So evolution provided 2 solutions – fire would promote seed shed from the capsules (gum nuts) in the tree tops while at the same time ‘sterilising’ the germination media (killing the root rot fungi spores in the surface soil). Voila! mass germination & establishment in the soil below if follow-up rainfall was favourable. But the regular burning by indigenous people ensured the country would remain “open” because eucs are very susceptible to fire within the first 2 years of establishment. However if follow up burns don’t occur within this time frame you can end up with a euc thicket – which is common in many districts to-day. River red gums & coolibah follow analogous mechanisms but in these cases the “sterilisation” effect enabling seedling establishment comes from flooding rather than fire. But like the dryland eucs you end up with a thicket if there is no subsequent fire within ‘say’ 2 years following the establishment event. So what did europeans do? Disrupt aboriginal burning management which kept the country “open” and then put out fires wherever they could to protect their livestock & their livestock’s feed supplies. There are heaps of examples of the predictable responses all over Australia. They lead to the phenomenon known by ecologists as ‘woodland thickening’ (e.g. currently over >60 M ha of Queensland) – a phenomenon which the atmosphere over Australia teleologically “sees” as a huge carbon sink, but which apparently our politicians & many contributors to this blog do not understand and cannot comprehend.
Hi Bill,
Good to hear from you and thanks for your insights.
The Barmah cattlemen and woodcutters claim that floods once controlled the redgum regrowth with young trees/seedlings easy drown.
Ofcourse with river regulation areas like Barmah flood less often.
Eric Rolls in “a Million Wild Acres”, Watkin Tench and numerous studies on charcoal deposits confirm that Australia was cleared by fire well before european settlement
Thanks for the contribution Bill. I do like the two quotes at the start of your main paragraph – hope you don’t mind if I use them…
cheers
Arnost
Go for it Arnost. And while you are at it think about the spillover effect of woodland thickening now that tree clearing is effectively banned in Australia. For example, we now have a huge carbon sink which we cannot include in our greenhouse gas emissions calculations. [Because we are wedded to the Kyoto Protocol (by both Labor & Liberal -even if the latter won’t ratify) & its usefulness to Australia is tied to the necessity to calculate net emissions in 1990 (the Kyoto baseline year) based on land clearing sources exceeding forest sinks. Hence reductions in land clearing can then be counted to determine our 2008-12 ‘commitment period’ totals (Article 3.7). Also we then have the perverse incentive to maximise stated net emissions in 1990 because Australia (selling itself as a poor bloody disadvantaged country)was allowed to actually increase net emissions to 108% of its 1990 baseline for the commitment period. Voila again! We cooked the books by only counting the sinks in c. 10% of our 1990 forests & woodlands. Meanwhile the US had the contrary incentive to include 100% of its forests & woodland sinks in its inventory (since notionally their Kyoto target was to proportionally reduce emissions in 2008-12, so this encouraged it to minimise its stated 1990 net emissions). Clearly both countries’ “Kyoto baseline inventories” would not survive international scientific audit & this could help explain the lack of ratification of the Protocol by both – forgetting the political gobbledegook of Johny & Dubbya. Tree thickening (now guaranteed since cockies can’t clear so called “remnant forests/woodlands” to facilitate our “Kyoto” needs) also has a couple of undesirable side effects (i) it leads to appreciable loss in livestock carrying capacity, & (ii) it greatly reduces rainfall run-off & streamflows. This is information based on hard science, not opinion. Finally, if we let our fire loving vegetation thicken up we don’t eliminate the fires – we merely ensure the inevitable fire will feature on the international news wires.
Bill,
I support what you say. We have the same problem in south-western Australia with thickening, thirsty jarrah and marri, and dangerously flammable thickets of native weeds such as Parrot Bush, Peppermint, Rock Sheoak, and Bull Banksia. The tuart are simply not reproducing, because they need ash bed, to provide nutrients, and probably prevent seed theft by ants.
The evidence for former regular mosaic burning in light fuels by Nyoongars (2-4 years generally) is overwhelming, but denied by some who are fire-ignorant, yet seem to have undue political influence. The fact that regular, light burning sequestered very large volumes of carbon as soil-improving charcoal seems to be ignored as politically incorrect.
All we can do is wait for the inevitable monster fires (karla koombaniny?) to shake urban white voters back to their senses. I predict that the media will make a facile link to climate change, but the need for more effective fire mitigation by fuel reduction should still be obvious.
Australia has been through the cycle several times since the 1930s, but, as a dog returneth to his vomit, so a fool returneth to his folly. Add current drought, potential co-ordinated arson by terrorists on trail bikes, and eco-mythology to the mix.
Welcome, (Sir) William Burrows, your presence has been sorely missed.
The treatment of vegetation under Kyoto Interruptus also explains why the agricultural sector has been left out of the Carbon Trading system. They want the whole issue of the missing (stolen) carbon credits from the clearing ban to slip out of view so the government can use them for their own ends.
The core principle of a cap and trade system is that any reductions in carbon emissions earn a credit that can be purchased by other emitters. The problem for Australian farmers is that our major emitters, the power generators, are government owned corporations. And if they cannot reduce their emissions then they will be in the market for credits.
And clearly, some people in the most likely centres of power have decided that the cheapest ones available are the misappropriated clearing credits.
The rightful owners of the clearing credits, worth more than $1 Billion a year, are the sum of all landowners who own trees and can no longer remove them. The fairest way to distribute the credits is in proportion to the volume of wood carbon they retain on their land.
The use of a single year as a benchmark for a rationing system, as Kyoto has applied to 1990, has produced serious anomalies and injustice in almost every instance it has been used.
The NSW Banana Growers, for example, used such a single cut-off date (week) for a system of supply quotas in the market glut of the late 1960s. But many growers tended to harvest on a fortnightly rotation and those who happened to harvest in that week were allowed to continue with weekly harvests that actually exceeded their long term average while those who didn’t were completely shafted.
As Bill has pointed out, the use of 1990 emissions as a benchmark is a recipe for injustice and failure. A far more appropriate benchmark would be to use a decadal mean and trend.
But can we seriously expect the people who designed and implemented the EEC Cheese mountain, the Wine lake, and whose subsidies did more to restrict third world agricultural production than any drought, to come up with a fair and equitable carbon trading system? Fat chance.
Our so-called rural leaders have not helped this cause by their failure to link Kyoto recognition to regognition of thickening sequestration.
Bill would have a better idea of the actual volumes and dollar values involved, but be assured, it is very big bickies that no politician nor public servant has any right to ignore.
Hi Jennifer,
1. You write: “This may explain why some foresters and aboriginal elders call river red gum ‘white fellas’ weed’ and why areas which were once open woodland are now covered in dense red gum forests including at Barmah.”
Pre 1840s – Aboriginal fire stick farming on a regular basis would have destroyed the periodic recruitment of seedlings in some areas where stocking of mature trees was low but records show there were also areas with dense stands of red gum.
In the absence of these fires all but the moira grass plains, with flood regimes that usually “drowned” young seedlings, remained open.
However, since river regulation these plains are being rapidly colonized with red gum.
These regularly flooded areas supported Open Forest 51-80% crown cover. Only small areas of Open Forest were cleared for settlement because of their position on the floodplain. The area of regularly flooded forests and wetlands is therefore largely intact (pre 1750!) on reserved public land and does not need locking up in a national park.
However, Woodland Forests 20-50% crown cover were extensively cleared.
[VEAC is trying to combine Open Forest and Woodland Forest classification into one to justify its 15% target under the CAR reserve system. Open Forest and Woodland Forest are two distinct EV Classes whose flooding frequencies and structure are quite different.]
2. Dense stands of red gum develop over time under favourable flooding conditions. Similar development to that in Central Murray forests also occurs on some Central Australia water courses – a good example east of Alice Springs in the Mount Benstead Creek area of the MacDonald Ranges.
Changed flood regimes have resulted in formerly open moira grass plains being progressively colonized by trees. Wildfire induced seedfall has also resulted in dense regrowth which you saw at Sandspit.
Hence active rather than passive management is required as you so well covered in the article on thinning ( http://www.jennifermarohasy.com/blog/archives/002543.html ).
Anon.
Dear Jennifer,
Years ago a chap from the Murray-Darling Basin Commission addressed the Murray Darling Association’s Annual Conference at Cobram. He spoke on pollen analysis from floodplain alluvium indicating that pre-humans there was a woodland along the Murray River. The arrival of the first aboriginals and their use of fire wiped out that woodland and for thousands of years the floodplain vegetation was grassland. River Red Gum invaded about 6,000 years ago. This is supported by a comment from the NPWS
There was no evidence of river red gum having fringed Lake Mungo which dried up about 15,000 years ago due to a minor uplift cutting off Willandra Creek.
I am led to believe that the aboriginals along the river used fire for cooking and warmth. The numerous and often quite large oven mounds indicate that there were significant aboriginal populations right along the Murray and Murrumbidgee Rivers. The aboriginals used fire to: (i) attract game to a fresh green pick; (ii) to also make game easier to spot and possibly to stalk; and (iii) to make it easier to spot the approach of friend or foe. They also found it much easier to carry fire in a coolamon (bark dish) than to create new fire by rubbing sticks together. If their fire sticks looked like going out while travelling they were freshened up in dry fuel before moving on. The new ground fire was left to burn itself out.
These relatively frequent but mild fires meant that relatively few seedling trees survived to maturity. More importantly, in my view, these frequent fires minimised the fuel build up on and in the forest floor. In the last 150 years we have tried to keep fire out which has allows an accumulation of fuel to build up on the forest floor. Each flood drops a load of silt on the forest floor which buries the fine forest litter. These days it is not uncommon to find a sequence of litter layers in the top soil. So now a forest fire can ignite the buried litter which quietly smoulders below the surface, ringbarking each tree it encounters. The heavy build up of shed bark leaves and twigs around big old trees greatly increases the risk of them igniting and burning from the inside out. Thus the damage potential of recent times is much greater than that of pre-1850.
Regarding your comment that VEAC wants more wood and grass. The lock up conservation VEAC recommends may allow more woody debris to accumulate but the ground flora will diminish in both species and number as the forest stands become more dense. It is not uncommon to see dense stands of advanced to mature growth with little more than forest litter fall on the ground, ie minimal biodiversity, not unlike what we see in an unthinned pine plantation.
Regards
Anon No 2
The tragedy for forest management is that we do not have any bench mark population counts for various stages of the climate cycle at key indicator locations. And this is no accident. The departmental greens have a very powerful interest in ensuring that the outcomes of their policies cannot be measured in terms of impact on biodiversity.
The proper assessment of these values would require sufficient data to allow one to determine whether a drought impacted population of Possums, for example, is higher or lower than at a comparable stage of a previous drought.
All we have are deliberately vague snapshots, mostly during good years, which provide little more than anecdotal value, but which operate as a defacto performance requirement. And of course, any departure from the good season anecdotal values are portrayed as evidence of global climatic change rather than simple seasonal or climatic cycling.
It is the classic MO of the dodgy corporate finance officer who obscures his fraudulent activities with an overburden of ambiguity.
Our public sector forests are managed by a corporate culture defined by a Skase style criminally negligent scum.
I have said that there is a mountain of evidence on frequent burning in the past by Aborigines. The Esplin Report on the 2003 Victorian fires glibly dismissed Aboriginal fire as irrelevant. Here is one historical observation.
“During my excursions in the bush my interest in bushfires has often been aroused … Others ascribe them entirely to the blacks … who light fires all over the place to cook their food but leave them unextinguished. During the hot summer the grass dries out and becomes highly inflammable, and the leaves of the myrtaceous plants, which are full of essential oils, also get very dry. The consequence is that bushfires quickly spread over enormous areas, though without becoming a danger to human beings…” Ludwig Leichhardt, 1842, New South Wales.
The observation that the fires were no danger to human beings is irrebuttable evidence of low fuel levels, due to a fire every few years. Recent fires in long unburnt National Parks in New South Wales were very dangerous to humans, and native animals, and would have been in Leichardt’s day, if there had been little, or no, burning.
If Mr. Esplin is interested I can supply much more historical evidence, and I have no doubt many other people, such as Dave Ryan and colleagues, can too. History is an essential part of ecology, but needs some insight. Perhaps Mr. Esplin’s expert advisers did not advise him well on this matter. Ignoring the dimension of time in ecology is dangerous.
Jennifer,
A good summary of the consequences of poor management in the Barmah forest.
It is important to consider two things.
One, that the Top Island fire was almost entirely within the Barmah State Park and was stopped only when it crossed into the adjoining, logged, State Forest.
The other (which has been touched on) is that the Barmah-Millewa group of forests has been influenced by humans since it was created.
The Murray at this point was dammed by an uplift, the Cadell Tilt, that occured after human settlement.
This caused the Murray to flow north along the Edward river which probably already existed as an anabranch. The Edward could not carry all the water and a series of large lakes and wetlands formed. This pool of water would have originally prevented the flood-sensitive e. camaldulensis from taking root. But the Murray then cut a new channel (one researcher claims as recently as 500 years ago) through to the Goulburn river, near Echuca. That section of river borders the Top Island fire area.
Edward Curr, whose squatting runs in the 1840s took in most of the Barmah forest, wrote of open forests and very attractive grassy plains within the forest. He also wrote about the practice of firestick farming and the constant campfires. He calculated that the pre-smallpox aboriginal population of the area had been several thousand. Several thousand people foraging daily for firewood would have had a considerable impact on the woody debris of the forest floor. Additionally the regular floods would have helped clear what remained.
Yet VEAC has decreed that the pre-European density of woody debris was 125 tonnes/hectare.
“The estimated current level of coarse woody debris in river red gum forests is approximately 20 tonnes per hectare, reduced from a pre-European level of about 125 tonnes per hectare” their draft report proclaims.
This is a late 20th century estimate which ignores the possibility of interference from mankind. VEAC appears not to have examined Curr’s observation; a great pity as he was the first European to see (and document) much of the forest.
To return to my first point, the State Park was set aside about ten years ago and has not been logged or grazed for years. Presumably it has been off-limits also for firewood collection. So the build up of woody debris had been considerable by the time the fire started.
What was possibly the worst firestorm in Victoria occurred on February 6 1851, “Black Thursday”. It incinerated, by contemporary estimates, about one third of Victoria in a single day. The smoke crossed Bass Strait bringing mid-afternoon darkness to northern Tasmania.
It happened after the aboriginal population, decimated by European diseases, had left their traditional way of life and become dependent on the new occupiers of their lands.
The resultant fuel load combined with a scorching northerly created a fire storm of previously unseen fury, though not unlike those which have confronted our firefighters in recent years.
Until late in the 20th century we had a fire-management policy built on the wisdom of the ages but in the rush to take humanity back to the dark ages of pristine wilderness all that sensible observation has been abandoned.
The thing that puzzles me most is that when a fire like Top Island occurs with its attendant loss of fauna and flora, we never hear any protests from those who campaign for more national parks instead of demanding that we make today’s lot safe for the wildlife they are supposed to protect.
Spot on, David. The greenocidal maniacs clearly do not give a toss about the well being of wildlife once they are brought under centralised green tenure. If they did then heads would most certainly have rolled long before this.
They practice the politics and ecology of exclusion. And as long as local communities and their legitimate uses are excluded from forests then the greens have no further need to waste a moments thought on the consequences of their “stewardship”.
You should write to the Vic Minister to formally advise him that the writings of Edward Curr are “relevant facts” within the meaning of the definition of proper exercise of power, which must not be ignored in determining a pre-european benchmark level of retained debris.
You could then suggest that he initiate a trial sequence of classical firestick burning to determine the likely proportion of his 125m3 that is retained after such a sequence has taken place.
That should rattle a few departmental dags.