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Current Issues Brief no. 8 2002-03
Bushfires: Is Fuel Reduction Burning the Answer?
Bill McCormick
Science, Technology, Environment and Resourses Group
10 December 2002
Effectiveness of Fuel Reduction Burns
Opportunity to Carry Out Fuel Reduction Burning
Environmental Effects
Escapes of Burns
Where People Live—Prescribed Burns and Blackened Bush
What Frequency for Fuel Reduction Burning
Bushfires have been and will remain a significant component of
the Australian landscape due to eucalypt species being the predominant
species in most southern Australian forest ecosytems. Since the available
forest fuel determines the amount of heat that potentially can be released
in a bushfire, low intensity burns to reduce the fuel loading in a forest
(fuel reduction burning) is one component that can be modified by land
managers to reduce fire risk.
Research has found that doubling the fuel in the forest will
double the rate of spread and quadruple the fire intensity. While
low intensity fires will tend to burn dead fuels below six millimetres
in diameter, medium to high intensity fires will burn young trees, thick
twigs and branches, bark and deep litter. Fuel reduction burning can
reduce the hazard of spotting from eucalypt bark, in some cases for
up to seven to ten years.
While fuel reduction burning is the principal means to reduce
the risks of bushfire, under extreme conditions bushfires can burn across
land with very low fuel loads, which would have been halted under milder
conditions.
Fuel reduction burning should not be applied uniformly, in terms
of frequency or extent, across Australia because of the diversity of
forests, topography and climates in southern Australia as well as the
different priorities that different land managers have in developing
specific burning regimes.
In order for fuel reduction burning programs to be effective
they need to be designed to be applied to specific vegetation types
and implemented by properly trained and resourced staff. Proper assessment
of these burns need to be carried out to show whether the results meet
the objectives of the program. Burning regimes are planned in advance
with the knowledge that some fuel reduction burns may not proceed due
to poor weather. Therefore the difficulties in carrying out fuel reduction
burning because of the need to burn in optimal conditions should not
be used as an excuse not to burn. There is normally an opportunity for
a fuel reduction burning program to be carried out if the land manager
has allocated adequate planning and resources to the program.
Topography is a significant component in determining the rate
of spread of a bushfire. The rate of spread of a fire doubles with every
ten degrees of increase in slope. This is especially important for the
movement of fires in heavily bisected country as occurs in the Sydney
region where fires can quickly run up from gullies to engulf houses
at the top of the plateau. Bushfires there pose a different sort of
risk compared with bushfires in forests growing in the more gentle topography
that is found for example in the southwest of Western Australia.
Priority needs to be given to strategic fuel reduction burning
to protect housing located near the relevant land manager's boundaries.
It is absolutely essential that all land managers (public and private)
are obliged to design and implement their fuel reduction programs to
protect life and property within and beyond their land boundaries.
Fuel reduction burning in the vicinity of urban areas are under
more constraints than those in isolated forested areas. The issue of
air pollution from smoke of fuel reduction burns increasing pollution
levels in urban areas is a significant limiting factor on when such
burns can be carried out. Burning can be unpleasant, reduce amenity,
kill plants and wildlife, and cause pollution so there is a built-in
political resistance to increasing the frequencies and proximity of
the burns.
Bushfires can drastically affect people, property and the environment
but they are also part of the natural variability of environmental events
and can be an important driver in changing or maintaining certain ecological
communities. Ever since they first arrived in Australia, humans have
altered the fire regime of particular areas of this country to protect
resources and to favour particular plants and animals.
The present drought conditions foreshadow a serious bushfire season
for southeastern Australia. After last summer's severe bush fires in
New South Wales there were calls for more frequent and extensive use
of fuel reduction burning of forests and other areas to enable firefighting
agencies to protect life and property. The frequency and intensity of
these fires to achieve this aim will have impacts on biodiversity, air
and water quality and aesthetic values of the natural environment and
there is always a balance of positive and negative impacts of any active
burning regime.
This paper will briefly examine the use of prescribed burning regimes
(fuel reduction or hazard reduction) in the forests of southern Australia
to protect people and their property from bushfires and at the same
time to maintain natural ecosystems. It will look at the trade-offs
that may be necessary and comment on the potential reduction in bushfire
risk arising from fuel reduction burning.
A briefing
paper was prepared earlier this year by the New South Wales Parliamentary
Library which gives an outline of the history of fire and bushfire in
Australia. It discusses the legislative framework for bushfire control,
bushfire hazard reduction works and the planning system in NSW and provides
a summary of the 2001–02 NSW bushfires.(1)
The New South Wales Parliamentary Joint Select Committee on Bushfires
issued a Report
on the Inquiry into the 2001–02 Bushfires.(2) One of
the terms of reference related to hazard reduction and other fire prevention
measures. Appendix 1 contains the Committee's recommendation that specifically
relate to hazard reduction burning. The hearings and the report of the
Inquiry are drawn on for some of the examples used in this paper, which
have some relevance for the rest of Australia.
Fire has been a significant part of the Australian landscape even prior
to the arrival of humans in Australia 50 – 100 000 years
ago. Lightning caused serious wildfires when the conditions were right,
such as during drought and when there was sufficient vegetation to act
as fuel to carry the fire. Humans brought anthropogenic (human caused)
fire to Australia and as a result, the number and frequency of wildfires
increased dramatically. The eucalypt forest of 100 000 years ago
formed a significant part of the forest vegetation but with the subsequent
increase in the occurrence of wildfire in the Australian landscape these
eucalypt forests expanded dramatically at the expense of the araucarias
and Casuarina(3). In his book Burning Bush,
Stephen Pyne stated:
By the time of European discovery forests and woodlands
comprised about 25 per cent of the Australian land surface; perhaps
70 per cent of those lands could be classified as pure eucalypt forest.
Eucalypts claimed about 16 per cent of the tropical eucalypt and paperbark
biomes, and an estimated 11 per cent of the cypress pine biome.(4)
The extent of fire lighting by indigenous Australians was significant,
with one estimate being that forty people inhabiting 3000 hectares (ha)
would light an average of 5000 fires annually.(5) They developed
firestick farming which created a variety of habitats to meet a variety
of needs: hunting, removing woody regrowth, and protecting rainforest
and specific habitats. Aborigines in Central Australia burnt to produce
a mosaic of plant communities in different stages of fire recovery as
protection against wildfires.(6) However some fires would
escape their expected path and become wildfires. Pyne noted that:
What made such fires tolerable was the nomadism of the
Aborigine and the millennia of burning that shaped the fuels. Without
a fixed habitat, the Aborigines could accommodate an unusually large
fire.(7)
The time between fires in forests varied between type of forests, with
estimates of the average interval between fires in dry sclerophyll forests
(sclerophyll means 'hard leaves'—referring to the small, tough evergreen
leaves) being as short as three years, while fires in Mountain Ash forests
on the mainland had an average fire interval of 100 years. The average
fire interval for temperate rainforests in Tasmania may have been 300
years.(8)
With the coming of Europeans the fire regimes changed as European fire
practices developed by trial and error and with different aims depending
upon the user of the fire:
The fire practices of the grazier did not synchronise
with those of the farmer, and both challenged the fire expectations
of the forester. The miner burned everyone's lands indiscriminately.
The urbanite understood only the terror of the bushfire. Each of these
groups so evolved, moreover, that practices suitable for one time and
place were unacceptable at a later time.(9)
While the farmer and grazier used fire to clear bush, burn off old
grass or reduce the fire hazard on the farm, the development we now
refer to as hazard or fuel reduction burning evolved in the twentieth
century with the practices of forest managers who were trying to protect
native forests from wildfires that damaged the quality of their forests
as sources of timber. The foresters found that protecting the forests
by excluding fire was a recipe for catastrophic fires, so they developed
a regime for regularly using low intensity fires to reduce the fuel
loads in the understorey of the forests. This practice was started in
the 1920s in the jarrah forests of southwest Western Australia as part
of a fire protection system(10) where prior to European settlement
there was an average interval between fires of 3.4 years.(11)
Subsequently the use of aerial ignition for fuel reduction burns to
create mosaics of burned forests developed in State Forests across the
country(12). Such burning regimes varied with regions; it
is not possible to carry out fuel reduction burning in some forests,
notably wet sclerophyll forests or rainforests, except in the karri
forests of southwest Western Australia.
The use of fuel reduction burning regimes is now well embedded as part
of fire protection systems throughout Australia. It is used in forests
managed by government authorities such as forestry agencies, conservation
bodies, local councils, as well as by private property owners.
Fire regimes vary in different parts of Australia due to climate and
vegetation type. The fire intensities depend upon weather and fuel load.
The rate of spread of a fire is affected by a variety of issues including
wind speed, moisture content of the fuel, fuel particle size, vegetation
height, fuel bulk density, percentage of dead fuels, and topography.(13)
The amount of fuel determines the amount of heat that may be released
in a fire but the rate at which that heat is released is determined
by properties of the fuel, weather, wind direction and topography.(14)
The McArthur forest and grassland meters have been developed to predict
fire spread rate in eastern Australia while Forest Fire Behaviour Tables
were developed for conditions in Western Australia. Such prediction
equations have their limitations in that they are fuel-type specific.(15)
However such predictors of fire spread are being upgraded with increased
knowledge.
Fire intensities vary and are the product of the heat yield of the
fuel, the amount of fuel per unit area and the rate of spread of the
fire. A 'low' intensity fire would produce less than 350 kilowatts per
metre (kW/m) of fire edge, 'high' would be 350–3500 kW/m, 'very high'
would be 3500 – 35 000 kW/m, and 'extreme' would be greater
than 35 000 kW/m.(16) There is a great variation of
a fire's impact on the forest, depending upon the intensity. Whereas
a low intensity fire may only scorch the leaves of the lower forest
crown, higher intensity fires will completely defoliate the entire crown
of the forest.(17) The effects of a fire are only partially
related to fire intensity. A fast moving grass fire in a forest, which
is as intense as a slower moving fire burning dense shrub understorey,
will not have the same impact on the forest overstorey because of a
lower total heat load from the fire.(18)
As mentioned above, topography is a significant component, along with
wind speed, direction and fuel dryness, of the rate of spread of a fire.
The rate of spread of a fire will double with every ten degrees of increase
in the slope.(19) This has implications for the movement
of fires in heavily bisected country as occurs in the Sydney region
where fires can quickly run up from gullies to engulf houses at the
top of the plateau. This poses a different sort of risk compared with
forests growing in the more gentle topography that is found for example
in the southwest of Western Australia.
It is also possible that 'spotting' from a fire, where flaming bark
and twigs are thrown into the air and ignite fires ahead of the fire
front, may increase a fire's spread rate and affect the fire suppression
efforts. However the main influence of spotting is to overcome the discontinuities
of fuel and topography. Fuel reduction burning can reduce the hazard
of spotting from eucalypt bark, in some cases for up to seven to ten
years.(20)
As mentioned above the amount of the available fuel determines the
amount of heat that potentially can be released in a fire. Therefore
fuel loading in a forest is the only component of the mix that can be
modified by land managers. This is the rationale behind the use of fuel
reduction regime in forests to protect life and property. However not
all the plant material in a forest is potential fuel for a fire under
normal circumstances. Also the amount of fuel consumed in a fire increases
with increasing intensity, assuming the fuel is dry. While medium to
high intensity fires will burn young trees, thick twigs and branches,
bark and deep litter, low intensity fires will only burn dead fuels
below six millimetres in diameter.(21)
However the size of the fuel component consumed depends on the moisture
levels. In extremely dry conditions even low intensity burns can consume
all the fuel on the forest floor and damage forest trees. This is the
reason that fuel reduction burns need to be carried out under conditions
when the lower layers of the litter bed are moist so the low intensity
fire only burns the smaller diameter fuels on the forest floor.(22)
Eucalypts shed a great deal of material, leaves, bark and branches,
which supplies the bulk of fuel in dry and wet sclerophyll forests.
While live shrubby fuels of less than four millimetres in diameter contribute
four tonnes per hectare (t/ha) in Jarrah forests, the dead bark on the
tree trunks may add another 10 t/ha.(23) Fuel accumulates
increasing with time since the last fire until it reaches some sort
of equilibrium quantity. For example in tall shrub land it will take
20 years to reach the maximum fuel potential.(24) Ranges
of accumulation of such quasi-equilibrium fuel levels vary between 11
and 24 t/ha while those in the wet forests in WA reach equilibrium levels
at around 35 t/ha.(25) It should be noted that research has
found that doubling the fuel in the forest will double the rate of spread
and quadruple the fire intensity.(26)
The quantity of fuel on the forest floor and in any vegetation layer
below the eucalypt overstorey or crown is essential to determining whether
the fire will burn into the upper levels of the forest. Dr Phil Cheney
of the CSIRO told the New South Wales Bushfires Inquiry that:
In stratified fuel types, such as forest fuels, some
fuel strata burn in the flame front when they are preheated by convention
from fire in fuels below them. Thus as the weather conditions worsen,
and fire intensity increases, increasingly elevated layers of fine fuels
eventually including the tree crowns will be involved in the flame front
… Independent crown fires do not occur in tall eucalypt forests Luke
(1961), Luke and McArthur (1978) because fire in the crown alone cannot
preheat adjacent crowns by convection and lateral heat transfer by radiation
is insufficient to maintain combustion.(27)
Fuel reduction burning is the principal means to manage the risks of
bushfire but the New South Wales Parliamentary Bushfire Inquiry Report
noted that under extreme conditions bushfires will burn across land
with very low fuel loads, which would have be halted under milder conditions
and the effects of fuel on fire behaviour will differ
depending on the type and structure of the vegetation, fuel arrangements
and moisture, and the type of terrain.(28)
In discussing the relationship between fuels and fire behaviour Dr
Cheney told the Inquiry that:
In terms of rate
of spread, the important fuel factors are those that affect the flame
length and the rate of ignition. These include fuel fineness, the bulk
density of the fuel bed—which is a combination of the total fuel load
and the height of the fuel bed—the continuity or spacing of fuels, particularly
if they are clumped as are many natural fuels, and the fraction of dead
and green material within the fuel bed.(29)
He indicated that these factors are difficult to measure so that in
the past available fuel load (fuels below six millimetres in diameter)
was used as a measure. The CSIRO is currently working on a numerical
index to replace fuel load in order to give a better predictor of fire
spread.
Fuel reduction burning is carried out by a variety of land managers
on both public and private land. The requirements and aims of each of
these burning regimes will be different depending on what priorities
the land manager has. This has led to significant differences in the
frequency and quantity of fuel reduction burning that is carried out.
As a result there are calls from different sections of the community
that a particular land management agency is carrying out too much or
too little burning. The debate surrounding the fuel reduction burning
issue sometimes results in simplistic solutions being put forward to
deal with a complex problem.
The following statement by the New South Wales National Parks and Wildlife
Service (NPWS) indicates the fundamental issues of concern in developing
and implementing a fuel reduction program:
Our objectives in
relation to fire management are first and foremost the protection
of life, property and community assets. We also have objectives in relation
to the maintenance and enhancement of biodiversity and the protection
of cultural heritage which influence our approach to fire management.(30)
This shows that fundamentally fuel reduction burning comes down to
protection of life and property but that other priorities of the land
manager (whether government or private) may influence how that aim is
implemented. Unfortunately it is those other priorities that cause the
debate that there is too much or too little burning carried out.
It should be noted that fuel reduction burning is part of a fire management
program that also includes fire prevention activities, other forms of
hazard control such as maintenance of fire trails and fire breaks, and
fire suppression activities. All these activities are essential.
There are two points to note in relation to the effectiveness of fuel
reduction burning. Does the burning actually reduce the fuel in the
forest to the desired levels and will the reduction in fuel levels achieve
the aim of being able to control bushfires. Fuel reduction burns will
not necessarily halt the spread of bushfires.
While it is intended that fuel reduction burns will be successful in
reducing fuel levels with the minimum of damage to the forest, this
is not always the case. Post burn assessments of the effectiveness of
prescribed burns in the Blue Mountains in the period 1990–97 found that
30 per cent of the burns had a negative result, 40 per cent were sub-optimal,
and 30 per cent could be rated as effective burns.(31) The
negative results occurred when there was more "creation of fuel"
than reduction of fuel, with "creation" of fuel being the
fire's curing of fuels rather than consumption of them. The conclusions
of the study stated:
The results indicate that the City of Blue Mountains
is not an optimal area for prescribed burning to be a successful strategy:
the climate of a large proportion of the dissected tilted plateau is
not conducive to the achievement of effective burns. The climatic window
of opportunity—outside the declared bushfire danger season—seems to
be quite narrow for successful burning. …While the majority of burns
were quite effective in removing understorey fuels below 0.5 metres
in height, in most cases shrubs above this height tended to be cured
rather than consumed.(32)
The above study indicates that fuel reduction burning may not be as
successful as desired in some forest localities so this needs to be
taken into consideration with any fire risk management assessment.
The effectiveness of fuel reduction burning is related to the fire
lighting pattern and there is a need to train people to carry this out
using the most efficient techniques. Dr Cheney of CSIRO is of the opinion
that prescribed burning in New South Wales will not be successful until
organisations approach the problem in a truly professional manner using
burning guides for specific vegetation types and a professional team
to implement the burning in a planned and systematic manner with highly
trained staff.(33)
Fuel reduction burns may not halt bushfires under severe conditions.
However, they do have some moderating effect on the fire and allow for
control when conditions improve. In order to put fuel reduction in context
with fire fighting under extreme conditions, John Fisher of New South
Wales State Forests told the New South Wales Bushfires Inquiry that:
The opponents of fuel reduction burning fail to realise
the operational difficulty of fighting a wildfire in extreme conditions.
The only option or tool that State Forests NSW has
available is the manipulation of fuel in the fire triangle (heat/ignition,
air, fuel) … There is no question that on extreme fire days we would
not attempt a direct attack in heavy fuels. Even in a fuel reduced area
on extreme days there is no question that fires would burn through those
fuels as well, but the moderating effect of that fuel reduction activity
is quite profound and is quite useful in the periods of the day when
those extreme fire behaviours wane. We use that through the nightshift
to effect further fuel reduction burnings or back-burns, as you have
seen, and that provides us with a safe and effective means to control
fires on our estate.(34)
There are a number of factors which decide the timing of fuel reduction
burning, the weather being the most significant one. Fuel loads need
to be dry enough to effectively carry out hazard reduction burning without
the conditions being so severe that the burn risks getting out of control.
Fuel reduction burning normally takes place in spring and autumn.
In Western Australia most of the burning is carried out in spring while
in NSW it occurs in autumn. There is normally an opportunity for a fuel
reduction burning program to be carried out if the land manager has
allocated adequate planning and resources to the program.
John Fisher of New South Wales State Forests told the Inquiry how the
fuel reduction burns carried out in autumn produce a favourable result:
Our aim with fuel
reduction burning is to burn a proportion of the landscape during autumn
when fuel moisture levels are sufficiently high, and sensitive environments,
particularly rainforest gullies, stream sides, buffers et cetera that
are sensitive to fire, are not impacted by fuel reduction burning. That
allows us to constrain fuel reduction burning in that period of time
to the areas that are short-term fire-dependent ecosystems—blackbutt
ridges, et cetera. That breaks up the fuels in the landscape and allows
an effective suppression effort. Our research demonstrates that this
has been quite effective.(35)
Burning regimes, including total exclusion of fire, will have a significant
impact on the species composition of a forest ecosystem. While no species
of sclerophyllous vegetation has been made extinct as a direct result
of burning, some plant species have been eliminated from local areas
due to frequent burning,(36) whether by wildfire or prescribed
burning (or both). Frequent low intensity burning will alter the composition
of the understorey plant species in dry sclerophyll forests even if
no species is lost. Some plant species require a high intensity fire
to regenerate.
Fuel reduction burning on a regular basis will alter the vegetation
and affect the animals living there. Studies have shown that frequent
controlled burns will adversely affect birds which favour shrubby undergrowth
(Golden Whistler) or dense leaf litter (Red-Winged Fairy-wren, Pilot-bird)
and where that burning opens up the vegetation, will favour birds that
require a relatively open understorey.(37)
While specific fire regimes carried out by conservation authorities
may entail regular burning to facilitate conservation of specific species
or ecological communities, fuel reduction burning regimes are aimed
at reducing fuel levels and not at maximising or maintaining biodiversity.
Such regimes can have significant effects on the continued survival
of plant species in an area.(38)
Avoiding the implementation of any sort of a fuel reduction burning
regime so that 'natural' ecosystems can be maintained (except where
such regimes are inadvisable, e.g. rainforest) is not really an option
except possibly in remote areas. The fact that many significant conservation
reserves are relatively close to settled areas necessitates action by
conservation authorities to minimise potential fire risk to life and
property.(39) However, fire regimes, especially in conservation
regimes, need not be uniform across habitats and it has been suggested
that:
Across temperate Australia, creating a uniform habitat
can be avoided by mosaic burning with a range of fire regimes, with
protection of long unburnt areas and ensuring provision of such areas.
The scale and pattern of burning needs to be adjusted to the area of
vegetation within each habitat type, the extent of isolation and the
habitat requirements of target species or communities. Such management
has been recommended across a range of Australian environments, often
with an emphasis on threatened species.(40)
The problem with such a scheme is that it needs to be properly funded
and the nature conservation agencies have not to date allocated sufficient
funds to carry out such a fire regime.
Some scientists believe that burning forests too often poses a serious
threat to biodiversity and that their cumulative effect may be as profound
as high intensity fires.(41) In evidence to the Bushfire
Inquiry, Professor Rob Whelan made the statement that he was surprised
at the emphasis given to frequent hazard reduction burning and that
it implied a pretence that the bushfire problem was a simple one that
could be met with a simple solution, frequent hazard reduction burning.
He told the Inquiry that fire ecology researchers have accepted that
frequent broad scale burning of forests, whether by fuel reduction burns
or bushfires, had detrimental impacts on biodiversity conservation.(42)
However other scientists have argued that this may be based on false
perceptions of widespread frequent and uniform burning. They argue that
prescribed fires will be patchy in coverage with different environments
having different frequencies of low intensities from annual to never.(43)
Low intensity fires will not consistently burn gullies. While NSW State
Forests aim to achieve up to 60 per cent coverage of gross burning area,
in some years this may average down to 20 per cent.(44)
The New South Wales Parliamentary Bushfire Inquiry Report referred
to the lack of relevant scientific research on the impact of hazard
reduction burning. It cited the State Forests submission saying that
it was not valid to extrapolate the findings of research on flora and
fauna life cycle analysis and responses to fire in general, to
the impact of fuel reduction burning.(45)
Any fuel reduction burning operation runs the risk of escaping control
and causing a bushfire. This is why fuel moisture, weather conditions,
control lines and ignition points must be carefully considered. Such
escapes can and do occur under the supervision of both government and
private land managers and can cause significant environmental and economic
damage. In April 2002 10 000 ha of Wyperfeld National Park were
damaged when a controlled burn escaped the containment lines of the
Victorian Department of Natural Resources and Environment.(46)
However the actual percentage of escapes of fuel reduction burns may
be quite small, for example the escapes of wildfires caused by escapes
from burns implemented under the supervision of the Western Australia
Department of Conservation and Land Management (CALM) was 7.5 per cent
in 1989–90, six per cent in 1990–91, five per cent in 1991–92 and three
per cent in 1992–93.(47)
More and more suburban housing is expanding into bushland settings
and there is a need to protect these buildings and their inhabitants
from bushfires. However, having native vegetation close to houses makes
it difficult to protect. CSIRO scientist Dr Cheney said that if your
house is 200 metres from the fire edge you have two per cent chance
of your house being caught alight and thinks that 100 metres between
housing and the bush is a safe margin. This safe distance increases
with slope because fire speed doubles with every 10 degrees increase
in slope.(48) In talking about the effectiveness of fuel
reduction burning he said:
For the first 18
months to two years [after hazard reduction] the fire will stop on a
prescribed burn. After two years it will continue to burn through it,
but it will burn at a lower and manageable intensity, and as the years
go by the intensity builds up as the fuel builds up. Prescribed burning
is not designed to stop fires. It is designed to reduce their intensity,
so the impacts are lower and you have a sporting chance of suppressing
it, even under extreme conditions.(49)
New South Wales NPWS fire ecologist, Ross Bradstock, said that to protect
Sydney housing:
We have worked out you have to burn 20 per cent of the
landscape per annum to significantly reduce the size of wildfires, fires
under severe weather.(50)
The magnitude of such a burning program around Australian cities such
as Sydney is immense if the aim is to significantly reduce the bushfire
potential in circumstances such as those of December 2001 – January
2002. The following factors would need to be considered in such a burning
program. The Warringah Pittwater Bush Fire Management Committee's Bush
Fire Risk Management Plan covers land managed by the National Parks
and Wildlife Service, Council Reserves and Community Land, Vacant Crown
Land and Crown Reserves and private property. Under this plan there
are a number of matters to consider when proposing a fuel reduction
burning regime:
-
any environmental assessment requirements that must
be carried out prior the burning
-
use of appropriate fire regimes which mean that fire should be excluded
from mangroves and rainforests, fire frequency should not exceed two
fires in 25 years in tall open forests, fire frequency should not
exceed two fires in quick succession each five years or greater than
30 years, and fire frequency should not exceed two fires in quick
succession each eight years, three fires in quick succession each
fifteen to thirty years or be greater than thirty years in tall shrubland/heathland
-
smoke management to ensure that smoke from burns does not contribute
to hazardous levels of particulate air pollution in the Sydney area
or that smoke drift is minimised into smoke sensitive areas such as
roads and/or settlements
-
catchment protection so as to protect soil and water
values to ensure that riparian vegetation cover is maintained which
can be effective soil and ash traps after bushfires
-
pest and weed management where weed spread can be
facilitated by fire, and
-
protected lands (lands on slopes steeper than 18 degrees or with 20
metres of specified rivers, creeks and lakes) need to have their vegetation
cover protected to protect soil and water quality.(51)
The above list shows the complexity of deciding how, when and where
to carry out a program of fuel reduction burning where the aims are
to protect life, property and the environment within the area and also
to protect, maintain and where possible enhance the natural and cultural
values of the area through the management of appropriate fire regimes.(52)
The issue of air pollution from smoke of fuel reduction burns increasing
pollution levels in urban areas is a significant limiting factor on
when such burns can be carried out. In 1995 smoke from the largest controlled
burn in more than 10 years driven by southerly winds caused pollution
levels to reach extremely high levels comparable to that endured during
the 1994 bushfires.(53) Private property owners require a
permit for bush fire reduction burning and this would be automatically
suspended where a No Burn Day is declared by the NSW Environment Protection
Authority.(54)
The fundamental issue in carrying out fuel reduction burning close
to urban areas is that many of the inhabitants prefer living in green
leafy bushland. Burning can be unpleasant, reduce amenity, kill plants
and wildlife, and cause pollution so there is a build-up political resistance
to increasing the frequencies and proximity of the burns. Obviously
after severe bushfires such resistance will diminish but will then increase
over time from the last bushfire. Most summers are not severe bushfire
seasons, for example in New South Wales approximately 40 per cent of
fire seasons are mild, 40 per cent are moderate and 20 per cent are
serious.(55) It is essential that research is carried out
to show the efficacy of the frequency and extent of a burning regime
as well as its environmental impact in specific forest types in different
regions.
Pyne cited estimations by McArthur in the 1960s of the extent that
prescribed burning should be practised in the States in the forests
of southern Australia:
Granted a five year rotation, he estimated that New South
Wales could get by with perhaps five per cent of its protected forests
burned annually, Victoria with probably
6–7 per cent, and Western Australia with 10–25 per cent; he implied
that Tasmania might need as little as 1–2 per cent. Converting these
annual quantities to the total forest fraction burned during the whole
cycle, he put the figure at 25 per cent for New South Wales, 33 per
cent for Victoria, 50–100 per cent for Western Australia, and perhaps
5–10 per cent for Tasmania. Thus he thought it 'unlikely, and perhaps
highly undesirable, that prescribed burning in eastern Australia should
ever approach the scale practised in the dry jarrah forests of Western
Australia'.(56)
These estimates are just that, estimates, and they
were made forty years ago. They also relate to State forests rather
than conservation reserves or forested private or crown land which may
have different priorities for frequency of burning, property protection
or conservation and biodiversity aims. In Western Australia fuel reduction
burning policy is for burning to be carried out at 3–6 year intervals
in drier forests and 7–9 year intervals in wetter forests so that approximately
70 per cent of State forest is rotationally burnt.(57)
Map: Major Public Lands in the
Sydney Region
Source:Map derived from base maps produced by the National
Parks and Wildlife Service. © Crown copyright 2002
Click on map for an enlargement.
The question of frequency of fuel reduction burning was discussed in
the New South Wales Parliamentary Bushfires Inquiry Report where evidence
was given that State Forests carried out annual hazard reduction burning
in about four per cent of its tenure area while the figure for the National
Parks Service and Wildlife Service was about one per cent.(58)
Part of the reason for this disparity could be that State Forests has
a financial interest in protecting the wood values in its standing crop
while the National Parks and Wildlife Service is more concerned about
protecting biodiversity.
The New South Wales NPWS manages seven per cent of the State and four
per cent of the fires start in national parks. In the past five years
less than 10 per cent of fires that started in the national parks escaped
the park while 20 per cent of the fires in national parks start in private
property or other lands.(59) The Director-General of NPWS
stated that NPWS is committed to hazard reduction but does not tick
off quotas for burning and it is not feasible to burn all parkland adjacent
to private property because of the danger involved. Intense fires such
as happened in Como and Jannali only needed 10 metres of unburnt fuel
to destroy properties. He cited examples where hazard reduction burns
were useful in giving firefighters time to save houses (Tarabaga Ridge
in the Blue Mountains National Park) and another example where they
made little difference (at Warragamba Dam.)(60) (see
Map)
The New South Wales NPWS was only able to carry out six days of fuel
reduction burning prior to the 2001–02 bushfires because of weather
conditions.(61) As mentioned earlier such problems with
carrying out the burning program should be planned for to ensure necessary
strategic burning is completed, since the burning program is carried
out every year. Therefore the question arises: what priority is given
by individual departments responsible for land management to ensuring
that adequate time and resources are allocated to the burning program?
NPWS has spent $9 million since 1994 on upgrading and buying fire management
equipment.(62) How much was spent over that time on its fuel
reduction burning program? Dr Cheney commented to the Inquiry that land
management agencies must be adequately funded to do both their own fire
protection and their own fuel management.(63)
It is quite likely that State Forests gives a higher priority to the
burning program than does NPWS because it specifically burns to meet
its management objective to protect its timber assets.(64)
It should be noted that fuel reduction burning is but one method of
hazard reduction employed by State Forests and the area grazed for hazard
reduction is six times the area burned on an annual basis.(65)
However both authorities take a strategic approach to fuel reduction
burning. Appearing before the Bushfire Committee, Dr Tony Fleming of
New South Wales NPWS stated that:
When we talk about
strategic hazard reduction burning, we really are talking about focusing
our attention on the assets that we need to protect, recognising that
that must be our primary responsibility, and ensuring that our hazard
reduction burning and other forms of activity are focused on achieving
the protection of those areas … we have done about 22,000 hectares of
hazard reduction activity within this (Southern) directorate over the
past four years. Our program for this year is still under way. We do
that in conjunction with various other forms of hazard control, such
as slashing and maintenance of cleared fire trails and fire breaks in
certain areas.(66)
There is no simple answer to the issue of fuel reduction burning because
of the diversity of forests, topography and climates in southern Australia
as well as the different priorities that different land managers have
in developing specific burning regimes.
While the first priority in any fuel reduction program is to protect
life and property, it is the other priorities that land managers have,
such as biodiversity protection or protection of wood values, that will
probably ultimately determine the size and frequency of the program.
Therefore it needs to be considered whether or not sufficient priority
is being given to strategic burning to protect housing located near
the relevant land manager's boundaries. The Bushfire Inquiry Report
did not refer to this specific issue but concentrated on whether fuel
reduction burning was being done and at what frequency. This was a major
defect in the report. It is absolutely essential that all land managers
(public and private) are obliged to design and implement their fuel
reduction programs to protect life and property within and beyond their
land boundaries.
In order for fuel reduction burning programs to be effective they need
to be designed to be applied to specific vegetation types and implemented
by properly trained and resourced staff. Proper assessment of these
burns need to be carried out to show whether the results meet the objectives
of the program.
While it is difficult to carry out fuel reduction burning because of
the need to burn in optimal conditions, this should not be used as an
excuse not to burn. Burning regimes are planned in advance with the
knowledge that some fuel reduction burns may not proceed due to poor
weather. Therefore the difficulties in carrying out fuel reduction burning
because of the need to burn in optimal conditions should not be used
as an excuse not to burn. There is normally an opportunity for a fuel
reduction burning program to be carried out if the land manager has
allocated adequate planning and resources to the program.
Is it possible that lack of resources, or resource allocation priorities,
limit the scope of fuel reduction burns by land managers such as nature
conservation agencies rather than the weather? Other land management
agencies, such as forestry authorities, with a financial interest in
protecting their wood resources assets, manage to carry out a significantly
larger burning program.
The topography of the Sydney region makes the potential fire hazard
far greater than for some other urban areas. Fuel reduction burning
in such areas is also far more difficult and may prove less effective.
It is unlikely that a fuel reduction burning regime of 20 per cent of
the region, as suggested as necessary by one researcher, could be implemented
noting the issues that must be considered for such burning in an urban
area. Therefore answers to addressing the fire risk for this region
need to be dealt with in a variety of ways, such as planning regimes
and firefighting capacity, in addition to fuel reduction burning.
Lastly, there needs to be more specific research on the impact of fuel
reduction burning on biodiversity conservation in different forest types
and regions so that burning regimes can be developed which protect life
and property and minimise their impact on fauna and flora on and off
nature conservation reserves.
1. That all public
and private owners and/or managers of land in bushfire prone areas of
New South Wales are made aware of their responsibilities to protect
their own and neighbouring properties from bushfire through active implementation
of appropriate hazard reduction regimes and the application of appropriate
standards in building construction and maintenance.
2. That by 30
March 2003, all state land management agencies should prepare schedules,
identifying those areas within their tenures where hazard reduction
activity has been planned but postponed in the previous 36 months.
3. That all state
land management agencies apply the necessary resources to ensure that
their annual planned programs of hazard reduction are achieved in each
reserve OR, where planned hazard reduction by means of controlled burning
is postponed more than twice in any reporting year, that contingency/catch-up
plans are developed and implemented within a reasonable time-frame to
be negotiated with the appropriate Bushfire Management Planning Committee.
4. That the Bushfire
Coordinating Committee should develop a Statewide communications strategy
to generate and disseminate educational and information materials about
the bushfire management process for the general public and for all stakeholders
involved in bushfire management. The strategy should accommodate specialised
information activities related to bushfire management undertaken by
individual land management agencies in NSW.
5. That the National
Parks and Wildlife Service should develop and implement a Statewide
strategy for community information, education and engagement in regard
to the responsible management of parks and reserves, including the training
of key personnel in large group facilitation and consultation.
6. That the NSW
Rural Fire Service should offer assistance to local government bodies
to assist in catch up activities, such as mapping and hazard reduction.
Where individual councils seek to apply a levy to undertake such work,
the Department of Local Government should give such applications sympathetic
consideration.
7. That implementation
of the Government’s strategy to streamline the approval process for
hazard reduction be evaluated by December 2003 by a review panel convened
by the Commissioner of the NSW Rural Fire Service. The review panel
membership is to include (but is not limited to) representatives of
volunteer fire fighters, private land holders, local government representatives
and other Government stakeholders.
8. That the reporting
procedures by all land managers for the implementation of hazard reduction
be standardised and adopted by the Bushfire Coordination Committee.
9. That performance
audits of implementation of Bushfire Risk Management Plans be undertaken
by the Commissioner of the NSW Rural Fire Service in accordance with
a Strategic Audit Plan to be approved by the Minister for Emergency
Services.
10. That consistent
with the emphasis on coordinated bushfire fighting, there be ongoing
cooperation between the planning and operational arms of the land management
agencies and the firefighting authorities in the implementation of hazard
reduction plans as well as in firefighting activities.
11. That all developments
approved in fire prone areas from the date of proclamation of the Rural
Fires and Environmental Assessment Legislation Amendment Bill 2002,
should make provision for a property protection zone within the area
of the proposed development in accordance with the planning guidelines
in the Planning for Bushfire Protection booklet.
12. That land
management agencies, including National Parks and Wildlife Service,
State Forests and Department of Land and Water Conservation, develop
Village Protection Strategies as part of their Bushfire Management Plans
for all settlements adjacent to their lands.
13. That the Minister
for the Environment, in appointing community members to NPWS parks advisory
committees, consider amending the criteria for community membership
to ensure that each committee has a member with firefighting knowledge
and experience.
1. the New South
Wales Government endorse the zoning approach involving Asset Protection
Zones, Wildfire Strategic Advantage Zones and Heritage Management Zones,
as defined in Bushfire Risk Management Plans and Reserve Fire Management
Planning, for bushfire hazard reduction.
4. The committee
recommends that the NSW Rural Fire Service prepare and distribute information
about the statutory requirements of the hazard reduction approval process
and potential legal and liability issues for individual land owners
in the conduct of hazard reduction burning on their own property.
5. The committee
recommends that the legal responsibility of owners and occupiers for
any loss or injury arising out of those persons performing hazard reduction
in accordance with the Rural Fires Act be referred to the Crown Solicitor
for advice. The extent of the cover provided by the usual house and
contents policy of insurance for this type of loss or injury should
be investigated.
6. The committee
recommends that the NSW Rural Fire Service examine and report to the
Minister upon the availability of members of the NSW Rural Fire Service
or other protected persons, including officers of local councils, to
carry out hazard reduction work on behalf of owners and occupiers so
as to afford them the protection contained in s.128 of the Rural
Fires Act 1997 or s.731 of the Local Government Act 1993.
2. That all active
firefighters be encouraged to participate in hazard reduction burning
exercises in order to obtain practical experience in fire behaviour.
-
Stewart Smith, Bushfires, Briefing
Paper 5/2002, New South Wales Parliamentary Library, 2002.
-
Joint Select Committee on Bushfire 2002, Report on
Inquiry into 2001/2002 Bushfires, Legislative Assembly, Sydney
NSW, June 2002.
-
S. J. Pyne, Burning Bush: A Fire History
of Australia, Allen and Unwin, North Sydney, 1991, p. 16 .
-
ibid.
-
ibid., p. 93
-
P. Latz, Bushfires and Bushtucker: Aboriginal Plant Use
in Central Australia, IAD Press, Alice Springs, 1995, p. 31
-
ibid., p. 101
-
M. Gill and P. C. Catling, 'Fire regimes and biodiversity
of forested landscapes of southern Australia' in Flammable Australia:
The Fire Regimes and Biodiversity of a Continent, eds, R. A. Bradstock,
J. E. Williams, and A. M. Gill, Cambridge University Press, Cambridge,
2002, pp. 351–69.
-
S. J. Pyne, op. cit., p. 185
-
ibid.
-
M. C. Gill and P. C. Catling, loc. cit.
-
S. J. Pyne, op. cit.
-
W. Catchpole, 'Fire properties and burn patterns
in heterogeneous landscapes' in Flammable Australia: The Fire Regimes
and Biodiversity of a Continent, eds, R. A. Bradstock,
J .E. Williams and A. M. Gill, Cambridge University Press, Cambridge,
2002, pp. 49–75.
-
M. Gill and P. C. Catling, loc. cit.
-
W. Catchpole, loc. cit.
-
M. Gill and P. C. Catling, loc. cit.
-
ibid.
-
W. Catchpole, loc. cit.
-
M. Gill and P. C. Catling, loc. cit.
-
P. Cheney, 'The Effectiveness of Fuel Reduction Burning for
Fire Management' in Fire and Biodiversity: The Effects and Effectiveness
of Fire Management, Proceedings of a Conference held 8–9 October
1994, Footscray, Melbourne, published as Biodiversity Series, Paper
No 8 Biodiversity Unit, Department of Environment, Sport and Territories,
Canberra, 1996, pp. 9–15.
-
W. Catchpole, loc. cit.
-
Dr Phil Cheney. December 2002 Personal Communication
-
M. Gill and P. C. Catling, loc. cit.
-
Joint Select Committee on Bushfire 2002, op. cit., p. 48.
-
ibid.
-
S. J. Pyne, op. cit. p. 354.
-
P. Cheney, loc. cit.
-
Joint Select Committee on Bushfire 2002,
op. cit. p. 47.
-
ibid.
-
Fleming, Transcript of 22 April 2002, Joint Select Committee
on Bushfire 2002, op. cit., p. 12 .
-
S. G. James, Evaluation of the effectiveness of prescribed
burns: a simple methodology for post-burn assessment of the achievement
of fire management objectives, Australian Bushfire Conference,
Albury, July 1999.
-
ibid.
-
Dr Phil Cheney. December 2002 Personal Communication
-
J. Fisher, Transcript of 3 June 2002, Joint Select Committee
on Bushfire 2002, op. cit.,
pp. 5–6.
-
J. Fisher, loc. cit., p. 5.
-
K. Tolhurst, 'Effects of fuel reduction burning on flora in
a dry sclerophyll forest' in Fire and Biodiversity: The Effects
and Effectiveness of Fire Management, Proceedings of a Conference
held 8–9 October 1994, Footscray, Melbourne, published as Biodiversity
Series, Paper No 8 Biodiversity Unit, Department of Environment, Sport
and Territories, Canberra, 1996,
pp. 97–107.
-
J. C. Z. Woinarski and H. F. Recher, 'Impact and response:
a review of the effects of fire on the Australian avifauna' in Pacific
Conservation Biology, vol. 3, 1997, pp. 183–205.
-
Tran and C. Wild, The Review of Current
Knowledge and Literature to Assist in Determining Ecologically Sustainable
Fire Regimes for the South East Queensland Region, Griffith University
and the Fire and Biodiversity Consortium, August 2000.
-
ibid.
-
J. C. Z. Woinarski and H. F. Recher, loc. cit.
-
E. M. Tasker, 'Australia wrestles with fires control', Australian
Geographic News, 11 November 2002.
-
Joint Select Committee on Bushfire 2002, op. cit., p. 51.
-
V. Jurskis, Fire management for conservation: reconciling
theory and practice in Proceedings Bushfire 2001, Australasian
Bushfire Conference, Christchurch 3–6 July 2001, pp. 190–4.
-
ibid.
-
Joint Select Committee on Bushfire 2002, op. cit., p. 53.
-
AAP, Bushfire damages 10,000 ha of national park, AAP
Story No 3238, 11 April 2002.
-
R. Sneeuwjagt, 'Fighting Fire with Fire' in Government
Risk Management, Issue No 4, December 2001.
-
Wahlquist, Living with the natural enemy
in The Weekend Australian, 5 January 2002
-
ibid.
-
ibid.
-
Warringah Pittwater Bush Fire Management
Committee, Warringah Pittwater Bush Fire Management Committee Bush
Fire Risk Management Plan, Approved Draft, 30 September 1999.
-
ibid.
-
Lewis, 'EPA bans controlled burn-off after air pollution goes
sky-high', The Sydney Morning Herald, 8 November 1995.
-
Warringah Pittwater Bush Fire Management Committee, op. cit.
-
S. J. Pyne, op. cit., p. 277.
-
S. J. Pyne, op. cit., p. 354.
-
J. C. Z. Woinarski and H. F. Recher, loc. cit.
-
Joint Select Committee on Bushfire 2002, op. cit., p. 42.
-
B. Gilligan, 'Shared Responsibility' in The Land, 24
January 2002, p. 11.
-
ibid.
-
ibid.
-
B. Gilligan, loc. cit.
-
P. Cheney, Transcript of 3 June 2002, Joint Select Committee
on Bushfire 2002, op. cit., p. 7.
-
Joint Select Committee on Bushfire 2002, op. cit., p. 41.
-
ibid.
-
Fleming, op. cit., p. 18.
-
Joint Select Committee on Bushfire 2002, op. cit.
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