Heritage 0308_Bushfire.pdf - Australian Heritage Magazine

‘This Continent
of Smoke’
- Captain James Cook, 1770
BY MARK KELLETT
Drought is baking the bush alive. The sun has scorched the few clumps of grass to dry straw, the sapling
eucalypts are dried to nothing but sticks and even mature trees are wilting. A tangle of bone-dry leaves,
gum-nuts, branches and snarls of shed bark covers the ground, more than ankle-deep in places.
Even at sunrise, the air is stiflingly hot, with ominous stirrings of a northerly wind. As the morning passes,
it builds to a screaming gale and, hot as a blast furnace, strips the land of its last remaining moisture. By
noon, the first harsh smell of smoke arrives on the wind, warning that conditions are about to become
much worse.
For a while, the smoke is invisible in a white-hot sky, but soon a dirty cloud spreads over the tree-tops,
raining blackened leaves across the land. The sun is reduced to a reddish disc and day fades to a rank
twilight. One of the cinders that falls to the forest floor is not merely blackened, but glowing. At first, it
seems that the ember may have died out as it hit the ground, but seconds later a small smouldering patch
marks where it fell. Flames begin greedily consuming the mass of tinder-dry litter. Given a few minutes,
the spot-fire would have slithered up the bark-bearded eucalypt trunks and run amok among the canopy,
but there is no time.
The onslaught of the main fire front is heralded by the smell of eucalyptus oil, boiled out of the leaves. In
the fierce heat, flames leap through the tree-tops at incredible speed, seemingly not even bothering to
spread to the ground. The canopy of each tree disappears in an instant with a flare of flame. In the few
seconds it takes for falling sparks and burning debris to ignite the mass of leaf-litter below, the fire-front
has bounded on far ahead.
Fire and the Australian bush

FOR MANY AUSTRALIANS,
both past and present, this
terrifying scenario is all too
familiar. Like red-back spiders
and tiger snakes, fire is a constant
threat for those who live in the bush.
The intensity of Australian bushfire
is a natural consequence of the forest
that fuels it, but fire in the Australian
landscape has also been greatly
influenced by people and the changes
they have wrought in the
environment.
Many plants of the Australian bush
– in particular, those of the dry
sclerophyll forests and woodlands, and
the semi-arid and desert areas – are
adapted to cope with periods
of drought and the nutrientdeficient
soils of our ancient
continent. Their leaves are
toughened and have relatively
small surfaces to prevent
wilting in dry conditions, and
they are retained for as long
as possible to optimise the
plant’s use of scarce nutrients.
To protect them from
browsing animals, the leaves
are often endowed with
various combinations of tough
surfaces, spikes and
unpalatable chemicals.
A consequence of these
adaptations, however, seems
to be an increase in the frequency of
fire. The same adaptations that
protect the leaves against herbivores,
together with the lack of water, act to
greatly slow down the processes of
decay. Hence when the leaves are
finally shed, they build up along with
branches and bark into a deep mass of
dry litter which is a prime fuel. On
top of this, the chemicals used for
defence by some species of sclerophyll
plant – particularly the eucalypts –
are highly flammable.
With large amounts of fuel on the
forest floor and a canopy stocked with
flammable chemicals above, the bush
needs just a single spark in dry
conditions to become an inferno.
Litter like this shed eucalyptus bark is prime fire fuel.
In response, many bush plants have
evolved ways of surviving fire. Many
eucalypts, for example, can survive
burning and regrow lost foliage from
protected buds. In most species, these
buds sprout from the trunk and
branches, giving the trees a somewhat
fluffy look in the few years after fire.
Others, like mallees and snow gums,
have buds that lie beneath the
ground, and new growth shoots from
the base of seemingly dead trees.
Perennial herbs that form the
understorey of the bush survive fire by
avoidance. They grow during the
cooler and wetter seasons, and die
back in the summer, when fires are
most likely. Their dead stems and
leaves will burn, but the living
underground bulb or tuberous
root mass of the plant survives
to grow again next year.
Many wattles are killed by
fire, but they have a strategy
to survive as a species. Their
seeds, shed in vast numbers
from pods, are induced to
germinate by the heat of fire,
and they then enjoy the
additional benefit of a rich
ashy compost to nourish their
growth.
Plants like the grass trees
(Xanthorrhoea) have a method
of dealing with fire that
combines aspects of those used
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y eucalypts and wattles. Though their
foliage burns readily, their trunk is able to
survive most fires. Afterwards, they not
only regrow their lost leaves but are
stimulated to flower, so that their seeds
will be set in the nutrient-rich ash.
Though many plants of the Australian
bush have these superb adaptations to
fire, there are indications that fire was
not always so prevalent in the Australian
landscape.
For much of Australia’s history, native
conifers like bunya pines (Araucaria),
were common in the northern areas,
while the south was dominated by the
southern beech (Nothofagus). Dry
sclerophyll forests, made up of she-oaks
(Casuarina), eucalypts and wattles
(Acacia), appeared as the continent
become cooler and drier, but ancient and
modern habitats were able to exist in
uneasy equilibrium. Roughly 45,000 years
ago, this balance was upset. The dry
sclerophyll bush lost most of its she-oaks
and expanded dramatically, pushing the
southern beech and native conifers into a
few tiny pockets.
Examination of sediment from many
parts of Australia shows that this
coincided with an increase in the
frequency of fire. Fire certainly has the
potential to contribute to such a change,
for, unlike eucalypts and wattles, native
conifers and southern beech are very
vulnerable to fire and some dry
sclerophyll plants like she-oaks and some
banksias can have difficulty regenerating
if repeatedly burnt.
However, several other aspects of the
Australian ecology also changed radically
at about this time, any or all of which
could also have contributed to the
reduction in the ancient flora. The
climate became more variable, possibly as
a result of a change in El Niño and La
Niña weather patterns. The giant animals
known as megafauna, many of which
browsed on shrubs and trees, had by this
time become extinct in some parts of
Australia and rare in others. Finally, the
first humans – the Aboriginal people –
had arrived.
By the time Europeans were becoming
aware of Australia, the Aboriginal people
TOP RIGHT: The dry leaves and resin of grass
trees burn readily during fire.
BOTTOM: After being burnt, grass trees sprout
new leaves and eventually flower.
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had been regularly burning dry
sclerophyll forest for thousands of
years. Though fire was very common,
leading Captain James Cook to
poetically describe Australia as “this
continent of smoke”, it was not
capriciously started by the
Aboriginals. It was part of a system
termed ‘fire-stick farming’, where the
timing, extent and location of burns
were carefully controlled, usually by
tribal elders. In middle to late
summer, a small area that had been
left to grow for between three to five
years was burnt under close
supervision, as John Lort Stokes
observed during the Beagle’s survey of
the Australian coast between 1837
and 1843.
On our way we met a party of natives
engaged in burning the bush, which
they do in sections every year. The
dexterity with which they manage so
proverbially dangerous agent as fire is
indeed astonishing. Those to whom
this duty is especially entrusted, and
who guide or stop the running flame,
are armed with large green boughs,
with which, if it moves in the wrong
direction, they beat it out.
It used to be thought that fire-stick
farming was employed principally as a
means of flushing game towards
hunters. Though doubtless fire was
used for this purpose, regularly
burning the bush had other, longerterm
benefits for the Aboriginal
people.
By opening the bush canopy and
returning the nutrients trapped in
leaf litter to the soil, fires encouraged
the growth of plants which
Aboriginal people liked to eat,
particularly the perennial herbs
whose bulbs and tubers formed an
important part of their diet. Burning
also made hunting easier, both by
promoting the grasses that their game
ate and by keeping the forest open,
which gave a hunter a clearer shot
with his spear.
The general effect of Aboriginal
fire-stick farming was to create a
patchwork forest made up of areas at
various stages of recovery from fire.
Leaf litter was never allowed to build
up, so the fires were low enough in
intensity for established trees to
survive, though young saplings were
often killed. As a result of the grazing
provided by the understorey of herbs
and grasses and control through
regular hunting, many animals had
relatively small, but stable,
populations.
Captain Cook said more than he
knew when he compared the
Australian bush to “plantations in a
gentleman’s park”, for it was no more
natural than a plantation or an
orchard. Like those European
artificial habitats, if the management
system was removed, the bush would
rapidly fall to weeds. This is exactly
what happened in uncleared areas
when Aboriginal people were
displaced and no longer exerted their
influence on the forests.
As the seedlings of trees and bushes
were left to reach maturity, the open
forest gradually closed, and
understorey plants were deprived of
light and drowned under a sea of leaflitter.
In some places she-oaks were
Continued on page 68
66 Australian Heritage

ABOVE: Black Thursday, February 6th 1851, William Strutt, 1825–1915, painting: oil on canvas; 106.5 x 343.0 cm. State Library of Victoria,
Image number H28049.
BLACK THURSDAY
The summer of 1851 had been hot and long, and the country had the appearance of a vast hay-field, blanched by the scorching sun, and
inflammable as tinder. One of the main fires originated at Bullock Creek, near the present Bendigo Diggings, where a scrubby district had
been fired by a shepherd with a view to clear it; the north wind when it rose fanned the kindling flames, and bore them on till they were far
beyond all control. Other fires in no ways connected with that which commenced at Bullock Creek broke out in different directions, and swept
as rapidly onwards.
So frightful was the celerity with which the fire travelled, that the swiftest horse could barely gallop away from it. Mile after mile was traversed
by the flames, and was left a smoking wilderness, with only smouldering ashes to mark the site of once peaceful homesteads. On the great
plains many flocks of sheep fell a prey to the devouring element, and drays that had been left standing, some perhaps with their helpless teams
still yoked, were totally consumed, and only the iron work left remaining.
The mighty sheets of fire hurried on, gaining force and fierceness as they advanced, darting out in long tongues over the parched flats, and
licking up the grass; as they reached the forests the flames curled round the ancient stems, and creeping to the top of the trees flew on from
one tree-top to another, while through the tangled undergrowth below roared a sea of fire. The flakes of burning matter were hurled aloft by
the wind, and borne across creeks and gullies, from one hill-top to another, and lodged on the house-roofs or hay-stacks of the settlers, finding
fresh fuel everywhere.
The heat of the air, which seemed all alight with sparks, became intense, nor was it cooled by the clouds of smoke and cinders that gradually
obscured the brightness of day, and converted it into a lurid and awful twilight. It was not surprising that many anxious persons, who saw
themselves surrounded with fire and smoke on all sides, and knew not whither to fly, gave themselves up for lost, and waited in trembling for
the sound of the last trump.
Extract from Glimpses of Life in Victoria, by ‘A Resident’, John Hunter Kerr, first published in 1876.
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Bush fire in Australia, Samuel Calvert, 1828–1913, print: col. wood engraving; 32.8 x 45.3 cm. National Library of Australia, nla.pic-an8927792.
able to re-establish themselves, and at
least hold their own against the
eucalypts and wattles. Major Thomas
Mitchell described the change in the
area around Sydney as early as 1838:
Kangaroos are no longer seen there;
the grass is choked by underwood;
neither are there natives to burn the
grass... ...the omission of the annual
periodical burning by natives, of the
grass and young saplings, has already
produced in the open forests nearest
to Sydney, thick forests of young
trees, where, formerly, a man might
gallop without impediment, and see
whole miles before him.
This new, neglected bush was prime
fire territory, and bushfire rapidly
became a frightening part of the
Australian experience. Lightning and
desperate attempts by Aboriginal
people to retain the fire-stick system
or to burn out the invaders were
frequent causes of fire, but so was
European ‘burning off’, used to clear
farmland, improve grazing and reveal
hidden mineral deposits, along with
carelessness with fire and arson.
Outlying farms, where Europeans
coexisted with bush to some degree,
were particularly vulnerable, as blazes
from the unmanaged bush outside
could easily spread into farmland in
periods of drought, as David Collins
noted in his Journal in 1792.
At Parramatta and Toongabbe also
the heat was extreme; the country
there too was everywhere in flames.
Mr Arndell was a great sufferer by it.
The fire had spread to his farm, but
by the efforts of his own people and
neighbouring settlers it was got under,
and its progress supposed to be
eventually checked, when an unlucky
spark from a tree, which had been on
fire to the topmost branch, flying on
the thatch of the hut where his
people lived, it blazed out; the hut
with all the outbuildings, and thirty
bushels of wheat just got into a stack,
were in a few minutes destroyed.
In 1838, the assigned convict,
Joseph Mason, noted that farmers had
learned to take precautions to protect
their precious wheat crops: “Most of
the settlers do not sow the headlands
of their fields but leave a border all
around which they plough up & suffer
to remain bare so that the fire may
not run in upon the wheat”.
Fires of this type were a severe
threat to the new Australians and
their property but with a concerted
effort by neighbouring farmers they
were usually contained. However,
after periods of prolonged drought, a
particularly hot day with high winds
could nurture a hellish inferno.
One of the most disastrous of these
firestorms broke out on the 6th of
February, 1851; later dubbed Black
Thursday. Numerous independent
fires, probably started by humans,
raged out of control in many places,
killing ten people and burning up to a
quarter of what would soon after
become the colony of Victoria.
Black Thursday was the first of a
series of firestorms that burned their
way into Australian history. Notable
among them are Red Tuesday
(1/2/1898) in which much of
Gippsland was incinerated, killing 12
people and destroying more than
2,000 buildings; Black Sunday
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(14/2/1926) where fires again hit
Gippsland and southern NSW, and
swept through the Dandenong Ranges
in Victoria, taking 31 lives; the truly
appalling Black Friday fires
(13/1/1939), that burnt a swathe
through Victoria and New South
Wales, killing 71 people; Black
Tuesday (7/2/1967) in which the
whole of Tasmania seemed to catch
fire, taking 62 lives and doing
significant damage to Hobart; the Ash
Wednesday fires (16/2/1983) that
burnt vast areas of Victoria and South
Australia, killing 75 people; and more
recently, the fires of January 18, 2003
that ripped through Canberra and
surrounding areas, killing four people
and destroying more than 500 homes,
and the fires of January 11, 2005 on
the Eyre Peninsula in South Australia
in which nine lives were lost.
The early great fires were the trigger
for the development of Australia’s fire
control organisations. Fire brigades
were established, initially as locally
based voluntary groups, and today
these operate as state authorities
backed by armies of volunteers. Firefighting
is their central role, but
strategies of land and fire
management, including the use of fire
to control fire, are equally important.
Incorporating fire into the firecontrol
system has proved to be a
complex issue. One approach favoured
legislation and fire-fighting forces to
totally suppress fire in the bush.
Though this strategy certainly reduced
the incidence of local fires, the buildup
of litter would eventually fuel
particularly destructive firestorms.
Another system advocated regular
burning as the Aboriginal ‘fire-stick
farmers’ had done. Though this does
serve to reduce the intensity of fires,
the results are unsightly and a
controlled fire can easily become an
uncontrolled one. Further, the process
is damaging when applied to firesensitive
or degraded habitats.
Bushfire is inevitable in Australia,
but the question is: are big fires
inevitable or can we learn how to
control them in different types of
landscape? Today, the management of
bushfire in our various landscapes –
from southern forests to the savannas
of the north – is the subject of a great
deal of research. The Bushfire
Cooperative Research Centre,
established in 2003, has brought
together scientists, fire authorities,
land-management groups and
FIRE IN WET SCLEROPHYLL FORESTS
As its name suggests, wet sclerophyll forest grows in wetter and often cooler areas than its dry counterpart. Though eucalypts dominate this forest,
the milder conditions promote an understorey of many kinds of ferns.
These forests grow in a climate that usually does not encourage fire, and there is no indication that Aboriginal people used their system of firestick
farming in them. However, after periods of prolonged drought, wet sclerophyll will burn readily. Several of the truly devastating fires in
Australia’s history, notably the Red Tuesday and Black Friday fires, have involved bushfire entering wet sclerophyll forest.
Due to the relative rarity of fires, wet sclerophyll plants have different responses to being burnt. The mountain ash, the tallest of the eucalypts, is
killed by fire. However, its gum-nuts are opened by the flames, and take root in the soil almost immediately afterwards. For this reason, most
stands of mountain ash are all of the same size, all having taken root after the same fire.
Though rare and destructive, firestorms are an important factor in shaping the character of wet sclerophyll forests, which, in the absence of fire,
would be displaced by fire-intolerant temperate rainforest.
The wet sclerophyll eucalypt pictured above has been struck by lightning. Unless the land is in drought, the fire has little chance of spreading far.
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Though the bush appears devastated after fire
(above), many plant species can recover quite
quickly (right).
emergency services from around the
country to improve our understanding
of fire and to develop environmentally
sustainable fire and land-management
strategies.
One thing is clear: fire has played a
major role in creating the Australian
landscape for a very long time and, if
the predictions about climate change
are correct, bushfires are likely to
become more frequent and more
intense. Without doubt, improving
our knowledge of the relationship
between fire and our environment will
be the key to learning how to live
with the danger of bushfire.
The Author
Dr Mark Kellett is a biologist and
freelance science writer.
Further Reading
Australia Burning: Fire Ecology, Policy and
Management Issues edited by Geoffrey
Cary, David Lindenmayer and Stephen
Dovers, CSIRO Publishing, 2003.
The Future Eaters by Tim Flannery, Reed
Books, 1994.
Burning Bush: A Fire History of Australia by
Stephen J. Pyne, Allen & Unwin,
1992. ◆
70 Australian Heritage