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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