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Department of Agriculture,
Fisheries and Forestry
Report for FICCRF Plantation Amplified Bushfire Risk Study
Regional Plantation Forestry Fire Risk Assessment
Context Study Brief for Central Tablelands NSW
November 2010
21/19654/161549
FICCRF Plantation Amplified Bushfire Risk Study
Central Tablelands NSW
Contents
Introduction
1
1.
National Perspective
3
1.1
Australia’s Plantation Estate
3
1.2
Climate Change Overview
6
1.3
Climate Change Impacts On Plantations
9
1.4
Trends in Australian Land Use and Demographics
11
1.5
Risk Context and Definitions
13
1.6
Plantation Fire Risk Factors
15
1.7
Plantation Fire Risk Management Approaches
22
1.8
The Potential Effects of Climate Change on Fire Risk Factors
26
1.9
Summary
32
2.
3.
4.
5.
Regional Plantation Profile
34
2.1
Location
34
2.2
Plantation Estate
34
2.3
Regional Plantation Forecast
39
2.4
Summary
41
Regional Climate Trends and Forecasts
42
3.1
Current Climate
42
3.2
Regional Climate Projections
43
3.3
Trends
44
3.4
Summary
46
Regional Land Use Changes
47
4.1
Land Use
47
4.2
Impact of Climate Change
50
4.3
Summary
51
Regional Demographic Changes
52
5.1
Population
52
5.2
Age
52
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5.3
Labour force and employment
53
5.4
Education
55
5.5
Income
56
5.6
Summary
56
Study Area Fire Risk Aspects
58
6.1
Risk Factors
58
6.2
Climate Change Impacts on Plantation Risk within the Study Area
62
6.3
Summary
65
7.
Identifying Adaptation Options
66
8.
References
67
Table Index
Table 0-1
Plantation study areas and corresponding local
government areas
2
Table 1-1
Change in Australia’s plantations (2005-2009)
5
Table 1-2
Reference documents
6
Table 1-3
Summary - Recent historical climate trends in Australia 7
Table 1-4
Climate factors impacting Australia’s plantations
Table 1-5
Predicted effects of climate change on forestry species 10
Table 2-1
Local Government Areas within the study area
34
Table 2-2
Study area statistics
37
Table 2-3
Central Tablelands National Plantation Region statistics37
Table 2-4
Study area rotation
Table 2-5
Annual plantation forecasts and Forests NSW wood supply
commitments
40
Table 3-1
Central Tablelands climate forecasts
45
Table 3-2
Rainfall seasonality
46
Table 4-1
Land use in the Central Tablelands study area, 2005
47
Table 4-2
Summary of regional climate change effects
50
Table 5-1
Median age, by LGA
53
Table 5-2
Study area population, by age category (2006)
53
Table 5-3
Level of non-school qualification (2006)
55
Table 6-1
Significant plantation fires within the study area
58
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37
Table 6-2
Climate change impacts within the study area
62
Figure Index
Figure 0-1
Key study outputs
2
Figure 1-1
Australia’s National Plantation Inventory Regions
3
Figure 1-2
Conceptual framework for considering bushfire risk to a
plantation
14
Figure 1-3
Sensitivity of Plantation Species to Fire
16
Figure 2-1
National Plantation Inventory Region location map
35
Figure 2-2
Plantations of the Study Area
36
Figure 2-3
Forecast Plantation log supply (Softwood) – Central
Tablelands NFIR
38
Figure 2-4
Plantation age class and silvicultural condition
38
Figure 2-5
Forecast plantation softwood sawlog supply by region
(DAFF 2007)
40
Figure 2-6
Forecast plantation softwood pulpwood supply by region
(DAFF 2007)
40
Figure 3-1
Study area mean annual rainfall
42
Figure 3-2
Study area mean annual temperature
43
Figure 4-1
Primary Land Use
48
Figure 4-2
Vegetation Groups
49
Figure 5-1
Central Tablelands study area population, by LGA (2006)52
Figure 5-2
Proportion of employment, by industry (2006)
Figure 5-3
Employment growth for selected industries (2001 to 2006)55
Figure 5-4
Gross individual weekly income (2006)
56
Figure 7-1
Identification of Adaptation Actions
66
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Introduction
This project is supported by funding from the Australian Government Department of Agriculture,
Fisheries and Forestry under its Forest Industries Climate Change Research Fund program (FICCRF).
The FICCRF has been established to address major knowledge gaps about the impact of climate change
on forestry and forest industries in Australia, with twenty projects supported under the fund.
Through research, this grant program aims to assist the forest industries to better understand the
implications of climate change and build industry capacity to adapt to predicted scenarios and capitalise
on emerging mitigation opportunities. Addressing knowledge gaps will assist commercial forest planners
and managers to better manage their forest assets in a changing environment. Generating information
and developing tools and expertise will assist sustainability benefits to flow through the value chain and
contribute to growth and development in forestry dependent communities.
Projects funded through the program aim to assist forest industry stakeholders to:
Adapt to changed climatic conditions through new technologies and techniques which encourage
different practices;
Manage carbon emissions and have greater ability to participate in a Carbon Pollution Reduction
Scheme; and
Better understand climate change and its future implications for their enterprise and region.
Mitigating the risks and the variability of climate to plantations has historically been a challenge for forest
owners and managers considering the often long rotation lengths involved. The effect of climate change
adds significantly greater challenges, including amplified bushfire risk, with the timing of forecast
changes potentially within the current rotation of existing plantations.
The longer growing periods associated with plantation forests creates a greater exposure to the risks of
bushfire than other primary industry enterprises. Climate change is predicted to increase these risks;
through more severe and frequent bush fire danger days, changes to the fuel landscape surrounding
plantation allotments, increased physiological stresses on plantations increasing their susceptibility to
bushfire, and demographic and social changes. These risk factors may create greater potential for
plantation losses and require increased expenditure on bushfire mitigation to reduce risk.
The objective of this project is to significantly improve knowledge about the nature and degree of climate
change amplified bushfire risks for the plantation forestry sector. This will enable more effective and
targeted adaptive responses to climate change risk at a range of levels from individual plantation owners
to consolidated industry level.
Recognising the key interest and knowledge of plantation industry participants in bushfire risk
management, GHD has partnered with Australian Forest Growers (AFG) and the Australian Plantation
Products and Paper Industry Council (A3P) for this study. The three main study outputs are shown in
Figure 0-1.
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Project Outputs
Regional Fire Risk Analysis
Workshops (6)
Regional Plantation
Study Briefs (6)
Final Study Report
+ Updated Study Briefs
Figure 0-1 Key study outputs
Six study areas identified for the study are ‘sub-regions’ of National Plantation Inventory Regions (DAFF
2006) (see Section 1.1). A Regional Plantation Forestry Fire Risk Assessment Context Study Brief has
been prepared for each of these study areas, to identify on a regional basis those risk factors that are
sensitive to the effects of climate change. Selected study areas and their corresponding local
government areas are shown in Table 0-1.
Table 0-1
Plantation study areas and corresponding local government areas
Green Triangle
South-west WA
North-east
Tasmania
Murray Valley
Central
Tablelands
South-east
Queensland
Grant
Albany
Launceston
Tumut Shire
Oberon
Hervey Bay
Glenelg
Plantagenet
Dorset
Tumbarumba
Bathurst Regional
Maryborough
Break O’Day
Towong
Orange
Tiaro
West Wimmera
Albury
Cabonne
Cooloola
Wattle Range
Wodonga
Blayney
Naracoorte
Indigo
Lithgow
Mt Gambier
Greater Hume
This context brief has been prepared for the Central Tablelands study area, and provides a desktop
analysis and evaluation of amplified climate change bushfire risk. This report provided the basis for
discussion at a regional workshop held in Bathurst (November 2010).
Report Disclaimers
Data used for the study area is sourced from 2005 data collected for the National Plantation Inventory.
Updates to the 2006 National Plantation Inventory Report were released in 2010, however updates to the
original data set used for the study area within the National Plantation Inventory Regions were not
available. Study area data is therefore five years old.
While GHD has taken care to ensure the accuracy of this product, GHD makes no representations or
warranties about its accuracy, completeness or suitability for any particular purpose. GHD cannot accept
liability of any kind (whether in contract, tort or otherwise) for any expenses, losses, damages and/or
costs (including indirect or consequential damage).
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1.
National Perspective
1.1
Australia’s Plantation Estate
Australia has 2,020,226 hectares of timber production plantations, comprised of ~51% softwood species
(1,020,051 hectares) and ~49% hardwood species (990,945 ha) (DAFF 2010). While only occupying a
small proportion of the total area of Australia (0.26%), Australia’s plantations are dispersed across the
continent, and can be grouped into 15 National Plantation Inventory Regions (Figure 1-1). These
groupings are loosely based on industry supply zones.
Figure 1-1 Australia’s National Plantation Inventory Regions
Figure Sourced from DAFF (2010)
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The major softwood areas are South-east Queensland, Green Triangle and the Murray Valley, with the
major plantation hardwoods areas in Western Australia, Tasmania and the Green Triangle. Ownership of
the plantation resource is largely private (62%), with the greatest public ownership in NSW, South
Australia (largely softwoods) and largest private ownership in Victoria, Queensland, Western Australia
and Tasmania.
From 2005 to 2009 Australia’s plantation estate expanded by 16.1% (280,776 ha), the growth largely
driven by expansion in hardwood plantations with more than 250,000 ha established across Australia
(Table 1-1). The greatest increases in hardwood plantations during this period were in Tasmania (76,492
ha), Western Australia (41,010 ha), Victoria (37,979 ha) and New South Wales (37,345 ha) (DAFF 2010).
The area planted to softwood increased slightly (3% or 30.017 ha), with minor increases in all States and
Territories except the ACT and South Australia. Specific trends and detail for the study area are provided
in Section 2 (DAFF 2010).
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Table 1-1
Change in Australia’s plantations (2005-2009)
TOTAL
TOTAL
2005
2009
0.0%
9,500
7,870
2,821
0.0%
331,623
383,182
0
0
0.0%
16,329
31,838
1.58%
95.0%
2.5%
2,108
2,108
0.0%
225,637
256,389
12.69%
13.6%
123,419
-0.6%
457
457
0.0%
166,962
182,545
9.04%
9.3%
71,600
77,098
7.7%
100
100
0.0%
227,200
309,190
15.30%
36.1%
23.1%
218,412
220,009
0.7%
1,463
1,438
-1.7%
384,599
424,150
21.00%
10.3%
311,823
15.1%
104,480
110,934
6.2%
2,305
2,305
0.0%
377,598
425,062
21.04%
12.6%
740,161
990,946
33.9%
990,034
1,020,051
3.0%
9,255
9,229
-0.3%
1,739,450
2,020,226
100 %
16.1%
42.6%
49.1%
6.5%
56.9%
50.5%
-6.4%
0.5%
0.5%
-0.1%
State/ Territory
Hardwood
2005
Hardwood
2009
% change
Softwood
2005
Softwood
2009
% change
Other
2005
Other
2009
% change
ACT
0
0
0.0%
9,500
7,870
-17.2%
0
0
New South
Wales
55,196
92,541
67.7%
273,606
287,820
5.2%
2,821
Northern Territory
14,090
29,599
110.1%
2,239
2,239
0.0%
Queensland
37,496
63,618
69.7%
186,033
190,663
South Australia
42,341
58,669
38.6%
124,163
Tasmania
155,500
231,992
49.2%
Victoria
164,724
202,703
Western Australia
270,813
Total
Proportion of total
FICCRF Plantation Amplified Bushfire Risk Study
Central Tablelands NSW
% change
0.39%
-17.2%
18.97%
Source: DAFF (2006), DAFF (2010)
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% Total
(2009)
5
15.5%
1.2
Climate Change Overview
Projections and forecasts relating to climate change are well documented, with a range of studies and
analyses identifying that climate change is real and the effects considerable (Table 1-2). A list of
reference documents providing an overview of the national trends and projections is provided in Table
1-3.
Table 1-2
Reference documents
Reference
Australian Academy of Science (2010) The Science of Climate Change, Australian Academy of Science, Canberra.
Battaglia, M., Bruce, J., Brack, C. and Baker, T. (2009) Climate Change and Australia’s plantation estate: analysis of the
vulnerability and preliminary investigation of the adaptation options, Forest and Wood Products Australia Limited, Hobart
Bodman, R., Falk, F., Karoly, D. and Settle, D. (2007) The Science of Climate Change – A Brief Overview, A Commissioned
Report for the Garnaut Climate Change Review, The University of Melbourne
CSIRO (2007a) Climate Change in Australia, CSIRO Canberra
Garnaut, R., (2008) Garnaut Climate Change Review Final Report, Cambridge University Press, Port Melbourne
IPCC (2007) IPCC Fourth Assessment Report: Climate Change 2007, Report of the Intergovernmental Panel on Climate
Change, Geneva
Lucas, C., Hennessy, K., Mills, G. and Bathols, J. (2007) Bushfire weather in southeast Australia: Recent trends and projected
climate change impacts. Report for Climate Institute of Australia, Bushfire CRC and CSIRO Marine and Atmospheric
Research
PMSEIC Independent Working Group (2007) Climate Change in Australia: Regional Impacts and Adaptation – Managing the
Risk for Australia, Report Prepared for the Prime Minister’s Science, Engineering and Innovation Council, Canberra
Stokes, C and Howden, M (Eds) (2010). Adapting Agriculture to Climate Change, CSIRO Publishing, Melbourne.
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Table 1-3
Summary - Recent historical climate trends in Australia
Variable
Overview
Figure2
Projection
Temperature Average temperatures
have increased across
all of Australia, in all
seasons over the past
50 years (up to 1.5 - 2
ºC). The number of
record hot days has
increased and record
cool days reduced over
the last fifty years, with
the last decade (2000-9)
the hottest on record.1
By 2030 annual warming
(relative to 1990) is projected
at ~ 1.0ºC (coastal ~ 0.70.9ºC, and inland ~1-1.2ºC).
Rainfall
Projections for 2030 indicate
little change in the north with
2 - 5% decreases elsewhere.
Atmosphere
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For 2050 -~0.8 - 1.8ºC (low
emissions scenario) and ~1.5
- 2.8ºC (high emissions).
For 2070 ~ 1.0 - 2.5ºC (low
emissions) to 2.2 - 5.0ºC
(high emissions). 3
Over the past 50 years
the geographic spread
of annual rainfall has
changed, decreasing on
the eastern and southwestern seaboard, and
increasing in the tropical
north-west. 1
Atmospheric
concentrations of CO2 in
2010 are ~389 parts per
million (ppm), up from
280 ppm in the preindustrial era. Emissions
are growing (~3.5% p.a)
and exceed the ‘worst
case’ scenario
projections of a decade
ago.4
3
In the coming decades
decreases in rainfall are
projected to vary by season,
with reduced rainfall in winter
(southern Australia), spring
(southern and eastern
Australia) and autumn (southwest Australia). The number
of hot dry days and intense
rainfall events is also likely to
increase. 1
CO2 concentrations measured at Cape Grim, Tas.1
FICCRF Plantation Amplified Bushfire Risk Study
Central Tablelands NSW
Plants will be growing in
increased CO 2 levels, which
can generate a positive
response in plants with
increased water use
efficiency and photosynthetic
rates.
7
Variable
Overview
Fire
Weather
Fire seasons over the
last decade have been
longer, with a shorter
interval between and a
higher number of Very
High fire danger days or
greater since the 1940s.
Analysis to 2007
suggested actual trends
were exceeding the high
emissions projections.
Stream
Flows
1
5
Rainfall declines have
reduced stream flows
and capacities of major
water storages. In
Victoria a 20% reduction
in rainfall since the mid1990s has resulted in a
reduction of inflows of
40%. 5 Current stream
flow is similar to worse
case climate change
projections. 8
Figure2
Projection
Extreme fire days are
projected to increase by 525% (low emissions) or 1565% (high emissions) by
2020, increasing to 10-50%
(low) and 100-300% (high) by
2050. Fire season is likely to
be extended6.
Increased wind speed is
projected in 2030 in coastal
regions ( -2.5% to +7.5%)
except for ~ 30°S latitude in
winter (Sydney-Perth) and
40°S in summer (Hobart)
where decreases are
projected (-2 to -5%).
Projected runoff – mean sensitivity (%) to a 1oC in global
temperature (from 1990). 8
Modelled annual runoff from
1997-2006 in the southern
Murray Darling basin was
lower than any other decade
in the previous 112 years,
and half the long term
average7.
Every 1% decrease in rainfall
decreases runoff by ~ 2–3 %
(runoff decreases by a factor
of two to three with rainfall),
therefore reduced rainfall and
increasing drought frequency
are likely to contribute to
significant water resource
problems. 8
CSIRO /Australian Bureau of Meteorology (2010). 2 Bureau of Meteorology Website. 3 CSIRO (2007a). 4 Stokes and Howden (2010).
Garnaut (2008). 6 Lucas et al. (2007). 7 Jones (2010). 8 PMSEIC Independent Working Group (2007). 9 CSIRO (2008).
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1.3
Climate Change Impacts On Plantations
The dispersed nature of Australian plantation regions across the continent will generate a different suite
of impacts for each region, not all of them negative, and largely borne by two species (Pinus radiata and
Eucalyptus globulus), accounting for 69% of the planted estate and grown over broad climatic ranges
(Booth et al. 2010). More significant impacts may result to those plantation species with limited ranges. It
has been identified that an increase in mean annual temperature by 2.5ºC would result in more than 400
of Australia’s eucalypts being outside their current climatic range (Hughes et al. 1996), though species
may continue to be competitive outside this range (Kirschbaum 1999). Whilst there is uncertainty about
the extent to which Australia’s plantations are susceptible to climate change, a range of factors likely to
impact plantation growth and persistence have been identified. These factors are summarised in Table
1-4.
Table 1-4
Climate factors impacting Australia’s plantations
Factor
Impacts
Temperature
changes
Positive and negative changes associated with increased and reduced growth response
Extremes of weather to become more common with greater frequency, intensity and duration of
heatwaves, and conversely fewer frost days (Bodman et al. 2007)
More heatwaves > may impact on seedling survival and increase bushfire risk
Fewer frosts > may enhance planting season or survival rates
Can increase Nitrogen mineralisation in higher rainfall areas, resulting in higher growth rates
Rainfall changes
Positive and negative changes associated with increased and reduced growth response
Likely to increase mortality where there are existing high water demands – may require reduced
plantation stockings
Droughts have significant impacts on mean annual increment of trees
Species
The two main plantation species (Pinus radiata and Eucalyptus globulus) have been successfully
established across a broad climatic range
Reduced rainfall may impact growth and wood characteristics
Less common species planted as first rotation may be more susceptible to climate change factors
Broad scale tree mortality
CO2 concentration
May result in increased growth response through greater water use efficiency and increased
photosynthetic rates, though these can be offset by other limiting factors and nutrient feedback
mechanisms (Kirschbaum 1999)
May also favour grass and weed species, creating an enhanced fuel layer
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Factor
Impacts
Pest and other
vectors
Changes in rainfall may create conditions more suitable for pest species, as stressed trees are more
prone to attack by secondary agents such as pests and pathogens. Insect and disease distributions and
habitat are forecast to move southwards and coastward (including tropical and sub-tropical pests moving
into temperate areas and into higher elevations (Battaglia et al. 2009)
Reduced frosts or severe winter temperatures may allow pest populations to build up over winter,
extending the time period over which they are able to attack host species
C:N ratio may impact species palatability
Herbicide efficacy may be reduced (Ziska and Teasdale 2000)
Land-use change
Decreased rainfall may require changes in land use from cropping/mixed farming to grazing
Fuel landscapes around plantations may change – more grassland (replacing cropping) and larger farms
potentially increasing the chance of large fire runs
Shrubs and legumes are more likely to be advantaged over grasses, potentially generating a trend to
woodier vegetation and impacting on broadacre grazing (Stokes et al. 2010)
Consolidation of farms may lead to less volunteers to fight fires and less people around to report them,
increasing reliance on other mitigation options
Demographic
change
Sea-change – tree-change impacts
Changes to ignition (cause and location)
Aging population and reduced volunteerism
The potential effects of climate change on specific forest species is presented in Table 1-5, based on two
modelling scenarios employed by Battaglia et al. (2009). Risk relates to risk of drought effects, while
uncertainty relates to the effects of variables such as plant response to elevated CO 2. The effects of
increased risk or uncertainty are evident in conflicting predictions for P. radiata response in the Central
Tablelands and Murray Valley study areas.
Table 1-5
Predicted effects of climate change on forestry species
Study area
Little change in risk or uncertainty
Increase in risk or high uncertainty
Green Triangle
Possible increased overall plantation
production
Increased production of E. globulus, E.
nitens and P. radiata
South-west Western Australia
Decreased production of E. globulus at the
eastern extent of the study area
North-east Tasmania
Increased production of E. globulus, E.
nitens and P. radiata
Murray Valley
Increased production predicted in P. radiata
and E. globulus plantations
Increased production of E. globulus, E.
nitens and P. radiata
Decreased production of P. radiata
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Study area
Little change in risk or uncertainty
Central Tablelands
Increase in risk or high uncertainty
Increased production of P. radiata
Possible decreased production of P. radiata
on western edge of study area
South-east Queensland
Increased production for mid to lower
northern regions of the hybrid pine estate
Under some climate scenarios drying is
forecast to have a severe effect on the hybrid
pine plantations
Adapted from Battaglia et al. (2009)
1.4
Trends in Australian Land Use and Demographics
1.4.1
National trends
The following trends are adapted and summarised from Barr et al. (2005), Productivity Commission
(2005), AECgroup (2010) and the project team’s knowledge of Australian land use change.
Demographics
There has been a long-term trend of declining farmer numbers, however this is now reaching a
plateau. Key drivers for males have been drought, interest rates, commodity prices and
increased participation in education. Key drivers for women have been increased participation in
both education and the workforce (i.e. off-farm income), and marrying at an older age. An
additional factor has been the corporatisation of traditional family farms.
Average farmer age has been rising over the last three decades, driven by declining exit rate
of older farmers (which in part reflects reduced inter-generational transfer of farms, and the sale
of farms upon retirement) and rising average age of new entrants (e.g. between 1981 and
2001 the average age of new entrants rose from 34 to 39, and the median age of farmers rose
from 44 years to more than 50 years over the same period). Land and Water Australia modelling
suggests that the average farmer age will peak in 2011-2015, after which time baby boomers will
start retiring from farming and the median age will decline.
Rural populations are projected to continue declining in broadacre agriculture areas (reflecting
ongoing farm consolidation to capitalise on economies of scale, maintain competitiveness and
counter declining terms of trade) however are likely to grow in high amenity areas that are
attractive to tree-changers and rural retirees. Indeed, there is already evidence of people
migrating from cities to regional towns, where housing and rentals are more affordable.
The median age of the population in high amenity areas is older than those areas that are
less attractive to tree-changers and rural retirees. This trend is projected to continue.
There is a declining availability of agricultural labour and required skills, primarily due to
agriculture being perceived as a less attractive study choice and career relative to other
industries, e.g. mining (which tends to be located in regional areas, has a greater capacity to pay
high wages, and requires a similar skill set to many agricultural activities).
Farm families are becoming increasingly dependent on off-farm income.
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Land use
Australia is experiencing declining farm numbers (and increasing average farm size) due to farm
aggregation, with total agricultural production being concentrated on fewer farms.
There is increased demand for environmental services such as improved water quality and
reduced soil erosion.
Rural subdivision is occurring in areas that are popular with tree-changers and rural retirees,
particularly towns that are more accessible from metropolitan areas. Reduced intergenerational
transfer of farms has escalated this trend, as subdivision provides an attractive alternative for
people who inherit land but do not wish to farm it.
The increasing popularity of some regional towns is driving land prices in these areas, which
makes it increasingly difficult for agricultural land use to maintain competitiveness.
In semi-arid areas, some landholders are moving out of grazing and instead using their
properties for agistment. When there are poor seasonal conditions in southern areas, stock are
moved onto these properties for grazing. Woody weeds (such as mallee regrowth) are not overly
palatable so tend to be avoided by stock. As a result, woody weeds can flourish in these areas,
particularly given that the frequency of smaller grass fires is reduced (as pasture is grazed
down). This increases the risk of a more substantial fire, due to the changed fuel profile.
1.4.2
Projected trends under a carbon price
Land use change arising from greenhouse mitigation policies was investigated by GHD (2010), on behalf
of the Australian Farm Institute. In particular, the project sought to understand the likely location and
scale of future plantings arising from the development of a market for greenhouse emission offsets in the
form of permanent plantation trees.
A desktop review of existing models of land use change suggested that if a carbon price is introduced:
There will be increased competition for agricultural land, for the establishment of carbon sink
plantations;
A variety of factors, in addition to the relative returns of agriculture and carbon sink plantations,
are likely to influence the rate and scale of land use change (socioeconomic, environmental and
institutional);
The area of both permanent plantings and commercial forestry is expected to increase;
Carbon sink plantations are likely to continue to be established on parts of properties rather than
across entire landholdings;
Land use change from agriculture to harvestable carbon sink plantations is most likely under a
low carbon price. The location of this land use change will primarily focus on the higher rainfall
areas of the east coast and existing commercial forestry areas such as the Green Triangle and
Tasmania, due to the presence of existing processing infrastructure and greater returns relative
to permanent plantings.
Within the higher rainfall zone, plantings will occur on less productive agricultural land (e.g.
dryland grazing); and
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Permanent plantings will become more viable as the carbon price increases, particularly in lower
productivity /lower rainfall areas. These plantings are likely to be most prevalent in Queensland
and NSW, northern NT, northern WA and south-west WA.
1.4.3
Regional trends
In addition to the trends characterising Australian land use more generally, a number of regional trends
are projected to develop as a result of climate change. These trends are considered in Section 4 of this
report.
1.5
Risk Context and Definitions
Bushfire is a real and established threat to property and livelihoods in Australia. Commercial plantations
are often located in or near areas that are particularly vulnerable to the onset and propagation of
bushfire. The level of risk to an asset, such as a plantation, from bushfire at any time depends on a
number of factors that can vary spatially and/or temporally (e.g. local terrain, slope and aspect, ignition
patterns, fuel characteristics and frequency of weather conditions that promote fire spread, etc.).
Observed changes in climate and the uncertainty about future climate conditions may impact on and alter
the current trends and patterns associated with many of the factors that can lead to ignition or
propagation of bushfire. In turn, these will affect the bushfire risk profile of a region and the level of
bushfire risk to which a plantation is exposed.
1.5.1
Risk from bushfire
Risk is defined in the new (2009) AS/NZS ISO 31000 Risk Management – Principles and Guidelines as
“the effect of uncertainty on objectives” noting that it is often expressed by “a combination of the
consequences of an event… and the associated likelihood”, or:
Risk = f(likelihood, consequence)… (1)
A framework and methods for the consideration of bushfire in the context of the above definition of risk
has been developing over about the past decade (e.g. Bradstock and Gill, 2001; Shields and Tolhurst,
2003; Preisler et al., 2004, Tolhurst et al., 2008; Atkinson et al. 2010). These prior works can allow us to
conceptualise that the level of risk to a plantation can be considered as outlined in Figure 1-2. Some
principles reflected in Figure 1-2 are that:
Likelihood refers to the potential that a bushfire might encroach on or engulf a plantation by
considering that a sequence of steps (namely: ignition, spread and penetration) would need to occur
to arrive at this outcome. The overall likelihood is the product of the likelihoods of those steps
occurring, and depends on local environmental factors, fuel availability and management and
intervention capability etc. that can all vary spatially; and
Consequence refers to the potential adverse outcomes associated with a bushfire encroaching on a
plantation. The obvious direct impact would be loss of plantation resources. Indirect impacts might
occur on the local economy through, say, loss of work or investments. The level of consequence can
vary depending on the value of the resource and the resilience of the local economy, etc.
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Likelihood =
Consequence =
Probability of ignition
X
Direct costs (e.g. loss
incurred by owners and
investors)
+
Probability of spread
X
Probability of penetrating
the plantation
Indirect costs (e.g.
resources shortages,
impacts on local economy,
insurance payouts, health
& safety of fire fighters)
Increasing consequence
Risk = f (Likelihood, Consequence):
HIGHER
LOWER
Increasing likelihood
Figure 1-2 Conceptual framework for considering bushfire risk to a plantation
1.5.2
General impacts of climate change on bushfire risks to plantations
It is worthwhile considering the current projections of how climate may change in the future and the
influence on specific components of the risk equation set out in Figure 1-2. GeoScience Australia
(Middelmann (ed.) 2007) has examined the influence of climate change on bushfire risks and identified
that in general:
There is likely to be an increase in fire-conducive weather conditions. This may extend the fire season
(requiring increased expenditure on preparedness and suppression);
Drier conditions in south-east Australia could lead to an increase in fuel availability, including earlier
grass curing and from increases in stand mortality. Pasture growth is very responsive to rainfall
changes leading to short term increases in fuel that may not be matched by stock increases; and
Longer, drier warm weather periods could reduce the time window available to undertake hazard
reduction activities such as prescribed burning in autumn and spring (though potentially creating
opportunities in winter).
All of these relate to the likelihood aspects (i.e. ignition, spread potential and management capability) of
determining bushfire risk to plantations. Conversely, it is difficult to establish credible scenarios under
which the direct impacts of climate change might bring about direct changes to the asset values of, or the
dependence of local economies on, plantations. Hence when considering the risks associated with
plantation damage or loss by bushfire, and the impacts that a changing climate might have on these
risks, it is apparent that the influences would primarily be on the environmental and social factors that
drive the likelihood of the event, rather than on altering the consequences.
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1.5.3
Focus of this analysis
With the above in mind, the remainder of this analysis focuses on:
1. Describing in detail the suite of factors that can influence the likelihood (and so the risk) that a
bushfire event could impact (penetrate and damage) a plantation, including both environmental
conditions [Section 1.6] and management capability [Section 1.7]; and
2. Identifying the possible direct and indirect impacts of climate change on each of these factors and
whether each of these individually might result in a positive or adverse effect on the overall bushfire
risk profile (recognising that these may be different for different regions or locations in Australia)
[Section 1.8].
1.6
Plantation Fire Risk Factors
This section identifies the key factors that influence fire risk in plantations. A range of factors are
described, and the way in which they influence fire risk is discussed. In the following section, issues
relating to how plantation fire risk is managed are discussed.
1.6.1
Sensitivity to fire
Softwood species used in timber plantations in Australia are relatively sensitive to fire. The impact of fire
on an individual tree will vary with the characteristics of the fire, and to a lesser degree with the species
impacted (FFMG, 2006). Pinus radiata, the most prevalent softwood plantation species, is at the more
fire sensitive end of the spectrum of softwood species used in Australia.
“P radiata is a fire sensitive species. It dies if the whole crown is scorched and in most stands this
occurs when the fire intensity is less than 2500kW/m” (Cheney 1982).
If ranked in order of decreasing sensitivity Araucaria cunninghamii and P.radiata are the most sensitive,
followed by the more fire resistant P.elliottii, P.elliottii-P.caribaea F1/F2 hybrids, then P. caribaea and
P.pinaster with a similar resistance (Figure 1-3). Pinus elliottii and P. caribaea hybrids may be adversely
affected by low intensity fire when young, however fire and crown scorch tolerance increases as
individuals mature (Carey 1992).
Crown scorch will typically reduce stand growth in all pine species, with the extent of crown scorch
determining the magnitude of the impact (FFMG, 2006).
Studies by Billing (1980) indicate that in stands where more than 50% of the green crown depth is
scorched, significant negative impacts on post-fire growth occur; however, where less that 50% of the
green crown depth is scorched impacts on growth are negligible.
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Figure 1-3 Sensitivity of Plantation Species to Fire
Eucalypt plantation species used in Australia are dominated by fast growing smooth barked species. By
far the dominant species is Eucalyptus globulus, with other prevalent smooth barked species including E.
nitens E. grandis, E. dunnii. Whilst the Eucalyptus genus is generally renowned for its resilience to fire,
the aforementioned species are among the more fire sensitive Eucalypt species, and where species are
grown for pulp even lower intensity fires may make timber unsuitable for market.
In a prescribed burning trial in an eight year old E. globulus plantation conducted in mild weather
conditions, low fire intensities of 320 to 585 kW/m resulted in varying degrees of crown scorch, with
smaller trees often totally defoliated, and significant mortality in some plots (Boness and Van Etten,
1996).
1.6.2
Plantation fuels and fire characteristics
Plantations accumulate dead fine fuel during their growth, typically in the form of leaf and twig litter, shed
bark and dead components of understorey vegetation. Fuel characteristics in plantations vary between
species, and are influenced by other factors, including plantation establishment, silvicultural practices
and site conditions. The fuel characteristics typical of P. radiata and E. globulus plantations, at different
growth stages and different silvicultural treatments are summarised below:
Pine (based on P. radiata)
In recently established pine plantations (age 0 – 3), fuel and fire characteristics will be dominated by
grass (or shrub) vegetation growing in the inter-row spaces. When inter-row fuels and weather are in
a condition to support a running fire, the fire is likely to cause significant damage to the young trees.
This may occur even under low/moderate fire danger conditions;
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In young plantations (age 4 - 8) the crown base remains low to the ground, with inter-row fuels still a
dominant factor in fire behaviour. When inter-row fuels and weather are in a condition to support a
vigorous surface fire, the fire is likely to involve the live foliage of young trees. This may occur even
at low/moderate fire danger conditions, particularly if fuel moisture remains relatively low;
Middle aged plantations (age 8 – 20) progressively develop a needle litter and duff layer, with dead
lower branches providing ladder fuels between surface fuels and the live crown base. Stands
awaiting thinning, and recently thinned, are prone to supporting vigorous fires which can involve
crown fire runs. This may occur even at low/moderate fire danger conditions, particularly if fuel
moisture remains relatively low. As age since thinning progresses, thinning slash decays down to the
surface reducing the vertical arrangement of fuel. This together with the increasing gap to the green
crown base and further decay of ladder fuels acts to reduce the propensity for crown fire
development (higher Fire Danger Rating (FDR) is required to bring on crown fire development
relative to younger unthinned or recently thinned stands); and
In late rotation (multi-) thinned plantations (21+), surface fuel accumulation and decomposition have
typically reached equilibrium (around 17 t/ha surface fuel), establishing with a gap between surface
fuels and live crown base exceeding 10 metres.
Under most conditions fire will be confined to surface fuels, however in adverse weather conditions
(Very High to Catastrophic FDR), fire behaviour can become sufficiently vigorous to generate
intermittent or sustained crown fire runs.
Eucalypt (based on E. globulus or blue gum)
In recently established plantations (age 0 – 3) the fuel characteristics are dominated by typically
grassy vegetation growing in the inter-row spaces. When inter-row fuels and weather are in a
condition to support a running grass fire, the fire is likely to cause significant damage to the fire
sensitive young trees. However, for running fire to occur, a high degree of grass curing will be
required, and sufficient wind speed to propagate fire across the planted rows, which in well managed
plantations are typically devoid of dead fine fuel due to weed control treatment and the juvenile blue
gum foliage being live and green;
By the time plantations reach mid rotation (age 4 – 6) grass fuels decline due to heavy shading and
are progressively replaced by leaf litter (from around age 4, blue gums begin to shed juvenile leaves
from lower branches and to self-prune from below). Initially, litter deposition is light and
discontinuous, but can reach around 4.5 t/ha by age 6 (Boness and Van Etten, 1996) with a light
continuous litter layer created by age 5 or 6. Fire behaviour potential during this period is at the
lowest stage of the rotation, due largely to the light and compact arrangement of the surface fuel,
shading and the wind reduction effects of the stand structure. As the surface litter becomes more
continuous in plantations approaching 6 years of age, in adverse weather conditions a vigorous
surface fire capable of causing high mortality is possible; and
In late rotation plantations (age 7-10+) litter deposition continues at the rate of around 1 to 2 t/ha
annually, typically reaching around 10 - 12 t/ha by age 10. Fuels are typically heaviest along the
rows in which bark streamer, and fallen twigs/branches become significant and can add vertical
structure to the fuel profile, particularly around the base of trees. Surface fuels in the late stage of
pulpwood blue gum plantations are sufficient in quantity and continuity to carry moderate to high
intensity fires. In adverse weather conditions intermittent or sustained crowning may develop.
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Under certain conditions, plantation fuels can be ignited and sustain combustion. Fuel accumulations can
ignite and will sustain combustion when their fuel moisture content falls below threshold values. For P.
radiata, typically fuel will ignite and carry fire with the assistance of wind at fuel moisture content below
about 20%. In Eucalypt fuel, combustion will not normally be sustained above a fuel moisture content of
around 16% (Tolhurst and Cheney, 1999).
In Australia, conditions in which plantation fuels become combustible occur annually and therefore
plantations are exposed to some level of fire risk every year. In years with significant rainfall deficiencies
(particularly spring and summer rainfall deficiencies), the length of fire risk exposure and severity of
exposure are amplified because a higher proportion of plantation fuels is available to burn for a longer
period. In Australia’s main plantation regions elevated risk seasons can occur several times per decade.
1.6.3
Adjacent landscape vegetation cover and condition
The landscape location where plantations occur will have a most significant impact on plantation fire risk.
The land cover and condition on lands adjacent to plantations, particularly in the direction from which
adverse weather comes, is particularly influential on fire risk.
Fires in forests are in general much more difficult to contain and keep contained than are fires in open
country dominated by pasture and crops.
This is because forest fires are much more intense, burn for longer periods, generate short to long
distance spotting, have more obscured visibility of the active fire edge, greater access difficulty and
require greater effort and resources per metre of fire line/containment line to suppress and mop-up.
Therefore, a plantation with extensive forest cover in the adverse prevailing up-wind direction will be at
significantly higher fire risk than one with adjacent grassland, particularly if the grasslands are well
grazed prior to onset of fire conducive conditions in the plantations (i.e. when plantations have dried out
sufficiently to carry fire). If the upwind forests are extensive, have heavy fuels, poor or limited access, or
are remote from resources for successful initial attack of small fires, then plantation fire risk is further
amplified. Cumulatively, these forest fire risk factors all make it more unlikely that fires in the adverse
prevailing up-wind direction will be contained before the onset of bad weather, the arrival of which is
likely to generate a forest fire of uncontrollable proportions which can directly spread into, or spot into the
down-wind plantations.
Historically, the majority of Australian plantation fire losses have been from fires starting outside the
plantation and burning into plantations as uncontrollable fires in adverse conditions (FFMG, 2006).
Analysis of historical fires is problematic due to difficulties with fire data availability and reliability. To the
extent that such analysis has been possible, there is reliable evidence that fires that have entered
plantations from adjacent land have burnt significantly larger areas of plantation than fires starting within
plantations. The overwhelming majority of major plantation fires (over 1,000 ha) including the Caroline
Fire, SA, 1979 (3,244 ha), Bondi Fire (Bombala), NSW, (6,457 ha), Ash Wednesday Fires, SA and Vic,
1983 (21,000+ ha), Glenwood Fire, NSW, 1983, (1,667 ha), Canberra Fires, ACT, 2003 (10,500 ha),
Stanley Fire, Vic, 2003 (1,291 ha) and Black Saturday fires, Vic, 2009 (16,000+ ha) all burnt into
plantations from adjacent lands, many burning as wide uncontrollable fronts.
1.6.4
Land use and management within the surrounding landscape
In the previous section the influence on plantation fire risk of land cover in the surrounding landscape
was discussed. Linking with this are the land management practices on these lands. For example
different agricultural practices on adjacent lands will affect fire risk to different degrees.
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Where grazing is undertaken on adjacent pastures, particularly if grass paddocks are grazed short (<10
cm) before plantations dry out after winter and spring rains, fire risk will be significantly lower than in
areas where grazing is absent, intermittent or light. Cropping practices can be similarly influential on fire
risk, particularly the timing of crop harvesting and the crop residue management practices. On forested
lands, the forest fuel loads associated with land management practices can significantly affect prospects
for initial attack success of fires starting in those forests.
Similarly, land use change from broadacre agriculture to plantations, arising from the introduction of a
carbon price, may increase fire risk due to changes in the fuel load profile. This may however be
mitigated by plantation owners’ incentive to invest in fire protection infrastructure. The extent of access
into adjacent forests for initial attack, multi-shift operations and fuel reduction burning will also have an
influence on adjacent plantation fire risk.
Demographic changes occurring in rural areas are also affecting land use and management, for
example:
Farm consolidation, increasing average farm size and declining farmer numbers are resulting in a
less managed environment in some areas. This can encourage the development of woody weeds
and reduce the likelihood of early fire detection;
Declining rural populations in broadacre agriculture areas is expected to reduce the likelihood of
early fire detection;
In other areas, rural subdivision can result in revegetation of traditional broadacre agricultural land
(e.g. in order to increase amenity or biodiversity value) thereby changing the fuel load profile;
Increased demand for environmental services is, in many cases, encouraging landholders to
revegetate. This has an impact on landscape fuel profiles; and
Subdivision tends to result in more people living on the land – therefore there is a greater likelihood
of early fire detection. However, tree-changers may have less understanding of rural fire behaviour
relative to farm managers.
1.6.5
Climate and weather
Climate and weather (weather is the day-to-day state of the atmosphere, whilst climate is weather
attributes of a locality averaged over a period of years – usually 30 or more) are key fire risk factors for
plantations. The climate dictates such things as how often the landscape will be in a fire prone condition
– the timing and length of the bushfire season, and exposure to risk-elevating climatic events such as
droughts in forested areas. The weather dictates the severity of fire conditions (wind speed and direction,
relative humidity and temperature) on any given day, which has a strong influence on fuel combustibility
and therefore on how fast fires can spread and how severely they will burn.
Climatic conditions vary considerably between and within plantation regions. Some plantation localities
have a climate which exposes plantations to longer and more severe fire season conditions than other
areas. Some plantation localities experience more days of severe fire weather and more severe weather
extremes than other locations. Areas with a severe fire climate (frequent long, dry fire seasons), and
which experience severe fire weather extremes (days of hot, dry windy weather) will have a much higher
fire risk than areas with milder climate and weather. It follows that changes in climate and potential
weather extremes will change fire risk.
South-western WA and mainland South-eastern Australia are recognised as having one of the most
severe fire climates in the world, and experience extremes in fire weather.
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1.6.6
Ignition issues
Another key risk factor is sources of fire ignition. Theoretically, even in places with extreme fire climate
and weather, if there is no fire ignition source, then there is no fire risk. In all Australian plantation regions
the presence of people provides sources of fire ignition, and in most regions the potential for dry lightning
ignitions provides the potential for multiple near-simultaneous ignitions.
Ignition source, frequency and timing differences between regions (and within regions) have an influence
on local fire risk. Increases in population density are very often associated with increases in fire risk
(because people are the leading source of fires).
However, populations have different attitudes toward fire and behave in different ways; therefore
population density on its own is not necessarily a fire risk amplifying factor.
In relatively densely settled rural areas, community attitudes toward fire risk and use will usually have a
significant bearing on ignition risk factors. In some plantation areas, local communities have a strong
culture of exercising care with fire use, are not tolerant of others using fire in a way that it will cause
unacceptable risks to others. Fires or smoke sightings are routinely reported in order to mobilise a
successful early response to extinguish fires. Local communities with such a fire culture tend to
characteristically have:
A high proportion deriving an income or livelihood, directly or indirectly, from enterprises which rely
on fire vulnerable natural/agricultural resources;
Experience of the impact and consequences of severe fires; and
Local fire authorities actively applying a disciplined approach to fire prevention and detection, to
investigating the cause and circumstances of reported fires, and to prosecuting offenders and
pursuing cost recovery.
There are also areas where plantations are a significant land use, however community attitudes in
relation to fire are more relaxed. In circumstances were land managers have a culture of lighting
uncontained and unattended fires, and where fire use in the landscape is common, community members
may be ‘desensitised’ to, and less inclined to report, fires. Local fire authorities may also not have a
culture of routinely collecting fire intelligence or investigating the circumstances of reported fires.
Examples can include areas where land owners and occupiers commonly conduct unbounded burning in
forests and woodlands to promote pasture regeneration, and/or burn off piles or windrows of woody
material or agricultural residues. In such areas, ignition risks are elevated. Other examples of high
ignition risk areas are near high population centres where some people may use fire in a careless
manner or engage in arson.
Where in the landscape ignitions occur is also an important factor influencing risk. In landscapes where
there are sources of ignition in an upwind direction (from where adverse fire weather comes), such that
fires can reach plantations as an uncontrollable bushfire, risks will be significantly higher than they would
be for areas where areas ignition sources are downwind or where ignition potential is primarily within the
plantation.
1.6.7
Local fire suppression capacity issues
Detection
Early fire detection contributes to improving initial attack response success. Landscape areas that have
good fire lookout coverage (from towers or aircraft) will therefore have lower risk factors than areas with
limited or poor coverage.
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Access to and within plantations for suppression
Road and fire trail network density and quality are limiting factors on how quickly and how close fire
suppression resources can get to fires starting in plantations. Importantly also, they provide a network of
available containment lines from which indirect or parallel attack containment strategies can be pursued.
The level and standard of plantation access will therefore influence plantation fire risk. Roads and trails
also provide public access to plantations, and may therefore become sources of careless or deliberate
fire ignition.
Access into the surrounding landscape for suppression
Roads and trails provide access for fire crews into land adjacent to plantations, where fires may start,
develop and spread into the plantation. The level and quality of access into adjacent lands, particularly
forested land, will be a limiting factor on initial attack success on the adjacent lands. Given that most
plantation fire losses have been from fires emanating from adjacent land, access for fire control on these
lands is an important risk factor.
Different types of firefighting resources required
There are a number of resources routinely required for first attack and extended multi-shift plantation
firefighting operations. The extent to which these are locally available and able to be quickly mobilised in
the event of a fire will have a significant influence on the level of plantation fire risk as they are limiting
factors on the speed and strength of response, and in particular initial attack. Resources for which quick
mobilisation will typically be required for successful initial attack on fires in, or threatening plantations
include:
Experienced plantation/forest fire crews and machinery operators (note: modestly experienced crews
may be able to successfully suppress fires burning in mild to moderate conditions, however, as the
level of suppression difficulty rises with increased fire danger, and the number and landscape
location of fire(s) and their perimeter length increases, fire crew experience levels will become more
of a suppression issue);
Fast response 4WD ‘striker’ units (400-600 litre capacity) which can rapidly access and support initial
attack operations;
Large capacity 4WD fire tankers (3,500 – 4,000 litre capacity) that bring sustained water and
firefighting apparatus to the fireline;
Small bulldozers for mineral earth containment line construction and widening;
Large bulldozers for use in stand conditions which are beyond the effective capacity of small dozers;
Surveillance system, such as a fire tower network, for initial fire detection and monitoring of
subsequent outbreaks;
Light fixed or rotary wing aircraft for aerial reconnaissance;
Waterbombing aircraft for initial attack and support of ground crews;
Radio equipment fitted to tankers and machinery to facilitate coordinated fire control operations; and
Accurate maps depicting landscape and fire control features.
The time taken to mobilise back-up resources for initial attack crews will also be important.
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1.7
Plantation Fire Risk Management Approaches
In this section, typical approaches currently used by plantation managers to manage plantation fire risk
factors are outlined.
1.7.1
Site selection
Site location and attributes will have a significant influence on the level of plantation fire risk. When
selecting plantation sites, in addition to considering plantation economics factors such as land cost, site
productivity factors and proximity to markets/processors, factors affecting fire risk should be considered,
as these will affect the probability of realising the full financial potential of the investment undiminished by
fire loss or damage. With regard to site selection, the following locality/site attributes are considered by
prudent investors:
The fire history of the locality (interval, large fire paths);
The extent of fire prone native bushland in the adverse prevailing up-wind direction from the site;
The land tenure and management practices on adjacent lands;
The proximity of fire prone native bushland to the plantation boundary;
The slope and aspect of the plantation site;
Type and proximity of main ignition sources in the locality;
The nature of road access to the area for suppression resources;
The extent to which detection infrastructure such as fire towers are already present in the area; and
The proximity and capacity of local fire management resources for initial attack.
1.7.2
Plantation design
Plantation design can influence the level of plantation fire risk. In particular, how the plantation is set up
to facilitate fire suppression can make responding to a fire in or threatening the plantation relatively
straightforward or very difficult. Prudent plantation design accommodates the following considerations:
Convoluted plantation boundaries should be avoided – the resulting perimeter trails/fire breaks will
be difficult and slow to traverse by vehicle, restrict visibility along fire breaks to short sections, and
be difficult and slow to conduct defensive backburning from. Plantation design should aim to provide
boundaries comprised predominantly of straights and shallow curves to facilitate ease of tanker
travel and defensive backburning from the plantation boundary, and seek to avoid to the greatest
extent possible tightly winding sections;
One or more primary access routes into the plantation should be designed to facilitate access for
heavy tankers and earthmoving plant transported by a prime mover and low loader.
Access design needs to cater for ready egress without the need for difficult multi-point turns; and
The primary fire management purpose of fire trails and boundary breaks is not to stop fires entering
or spreading through plantations (although breaks may halt the progress of low intensity fires under
mild conditions). The primary fire management purpose is to provide access to vehicles and plant for
suppression, and to provide a network of mineral earth breaks from which flank attack operations
and backburning operations can be conducted. Therefore, in designing the plantation, the position
and alignment of internal trails can benefit from being aligned with the expected travel direction of
adverse fires to provide logical areas for flank attack.
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Trails can also be usefully positioned at narrow sections of the plantation that may connect open
flats near riparian zones, particularly where these are orientated perpendicular to expected fire
paths. Such areas can provide locations to attempt head fire control in moderating conditions.
1.7.3
Silviculture
Silvicultural treatments can be used to modify fire risk factors. The most commonly used treatments are
pruning and thinning in pine plantations. Mostly however, silvicultural practices are used principally to
optimise tree growth, form and timber quality, with fire management benefits being incidental or
secondary. High pruning treatments for the principal purpose of fuel structure modification (removal of
ladder fuels) is used in limited areas, particularly next to high value potentially fire vulnerable assets,
along or around high potential ignition features (e.g. public roads and picnic areas) and adjacent to
strategic fire breaks.
1.7.4
Fuel reduction burning
Considerable research into the effects of prescribed burning in pine plantations was undertaken in the
1970s and 1980s. The broad conclusions of the research efforts were that prescribed burning could be
undertaken in pine plantations from around age 11 causing little or no damage to the growing stock and
without negatively impacting growth rates. However, great care was required to achieve damage free
results, particularly careful selection of fuel moisture conditions such that duff fuels and heavy fuel
accumulations are not ignited. Despite this body of research and the burning guides produced from it,
prescribed burning in pine plantations is not a widely used practice today. Its use is mainly confined to
arson problem areas where if prescribed burning is not used, it is expected that arson fires will be
inevitable and result in high levels of damage and loss. Burning in pine plantations (P. radiata and P.
pinasta) is still a routine management practice in parts of WA, particularly close to urban areas where
arson is a major problem.
1.7.5
How plantation fires are suppressed
Initial attack to keep small fires small
The key fire response strategy for plantation protection is to respond early to all fires on or near
plantations and extinguish the fire before it can develop to uncontrollable proportions (commonly referred
to as early and aggressive ‘initial attack’). This entails having an effective and rapid initial attack
capability. To successfully achieve this strategy requires a number of key capabilities:
Trained, competent and fit fire crews who are practiced at using both wet and dry firefighting
techniques in forests and plantations, and who are experienced in night firefighting, as fires which
start in the afternoon often require operations continuing well into or through the night. Crews also
need to be familiar with plantation fire behaviour in order to manage safe and effective operations,
as plantations can have significantly different fuel and fire characteristics to native forests,
particularly in relationship to crown fire escalation;
Because plantation firefighting tactics almost always aim to minimise area burnt (the longer the fire
perimeter, the greater the risk of fire escape and re-ignition), initial attack firefighting commonly
involves the use of earthmoving machinery for containment line construction. Therefore, to maximise
firefighting success, fire crews should be experienced at earthmoving machinery supervision, and
have experience in the capabilities and limitations of using different machinery types in different
plantation stand characteristics;
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Landscape visibility in plantations is often restricted due to stand height and density, and it is
relatively common for fire trails not to be signposted or named and marked on maps. Navigating in
plantations and making wise selections of trails for access and containment is greatly improved in
workforces that have good local knowledge;
Fire crews need to have a culture of disciplined, sustained attention to detail in mop-up due to the
presence of coarse dead fuels (e.g. logs, stumps, and slash) and fine fuel accumulations (e.g. bark
heaps and duff fuels) which frequently cause re-ignitions and spot-overs if not dealt with rigorously;
and
Increasingly, water-bombing aircraft are used in initial attack operations to slow the development of
fires while ground crews deploy to the fire, and to support ground crews by undertaking such actions
as quelling hotspots and flare-ups within containment lines, identifying trouble-spots for containment,
and looking for and attacking spot-overs. Where aircraft are used in conjunction with ground crews,
the ground crews need to be familiar with working with aircraft, and how to use aircraft to best effect.
Fire crews which are inexperienced in direct and parallel attack forest fire control techniques working
with machinery, and potentially also aircraft, are less effective and productive than experienced
crews, and have a lower probability of achieving successful containment.
Sustained suppression operations on large plantation fires
No matter how well resourced, trained and organised fire crews are, there always remains some level of
residual risk that some small fires will escape initial attack efforts and become running plantation fires
that can burn large areas and cause significant damage before they can be brought under control.
Examples can include situations when multiple ignitions occur (e.g. lightning or arson attacks) and during
extreme fire weather when fires can reach uncontrollable proportions quickly before fire crews arrive.
The ability of fire crews to undertake containment of large plantation fires can have a significant bearing
on the extent of plantation loss and damage incurred. The firefighting techniques, equipment and skills
involved in controlling large fires have important differences to those required for small fire initial attack.
Fire crews which are skilled and experienced at initial attack fires may not necessarily have optimal skills
and capacity for the containment of large fires.
A useful starting point for considering what skills and capacity are optimal for limiting the losses and
damage from large plantation fires is to consider some of the key features of such fires:
Large plantation fires almost always involve periods of rapid and intense fire spread, when the
headfire is uncontrollable, with substantial short to medium distance spotting ahead of the head fire;
When fires burn over a period of days there will almost always be significant changes in wind
direction which create different headfire spread directions at different times during the duration of the
fire. The major fire runs are usually punctuated by periods of relatively slow fire spread and mild fire
behaviour (e.g. overnight when good diurnal relative humidity recovery is achieved and high wind
speeds are not sustained during the night). These night-time periods provide the major opportunities
for containment;
Large plantation fires usually involve significant fire perimeters with long, often irregular flanks
burning in a range of different fuel ages and characteristics, and potentially also with fire burning in
pockets of retained native vegetation;
Large plantation fires usually occur during drought years when flaming or smouldering combustion
can be sustained for many days or weeks in the absence of good rainfall;
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There will almost always be significant sources of heavy course fuel and fuel accumulations inside
the fire perimeter which may harbour ‘hot-spots’ from which re-ignition, flaring and spotting across
containment lines can occur. In recently logged or thinned plantations hot-spot sources may be
abundant and extensive; and
Some plantation stand characteristics are such that within-compartment mineral earth containment
line construction is impracticable, except at small scales (e.g. around isolated spots), particularly in
plantations awaiting first thinning, and harvested areas with extensive accumulations of logs, heavy
branches, pushed out stumps and heavy logging slash.
Therefore, the successful containment of large plantation fires such that the extent of damage is
significantly reduced from what would otherwise have been incurred, involves many or all of the
following:
Highly competent field supervisors with a high level of forest and plantation fire experience, local
geographic and fire weather/behaviour knowledge, with ability to fill field command roles is the most
important capacity element for successful large fire control. At large multi-shift fires where there may
be several Divisions and a number of different tactical operations occurring simultaneously (aerial
operations, major dozer line construction, backburning and burning out operations, community and
critical asset protection operations, and extensive mop-up operations over many kilometres of fire
perimeter) the number of such personnel to achieve continuous day and night shift operations will be
significant and limiting;
Extensive use of heavy machinery to contain headfires within plantation compartments, using
close parallel attack, in severely time-constrained periods of reduced fire behaviour, including at
night and in difficult terrain. This plant is also critical for the widening of breaks along flanks and
sections requiring mop-up to reduce the potential for escapes;
Skills and experience to safely and quickly light-up and manage extensive flank burning out
operations (sometimes over many kilometres) in a range of different fuel types, from plantation
roads/trails along what can be extensive and active fire flanks, and without aerial reconnaissance or
waterbombing support (e.g. at night);
A significant level of heavy and light tanker resources available to keep flank fire and burning-out
operations contained and to support burning-out operations. For example, during the peak of the
10,866 ha P. radiata Billo Road Plantation Fire in the NSW Southern Tablelands in 2006, 51 heavy
fire tankers and 40 light slip-on units were deployed, which had severe difficulty maintaining
containment;
Provision and coordination of bulk-water transporters to replenish fire tankers on the fire line and
minimise the need for tanker units to leave assigned areas to replenish;
Multiple aircraft available to be engaged during the day on waterbombing spot-overs in open
country, supporting containment and mop-up operations by quelling major hotspot flare-ups to
prevent spot-overs, and potentially also to conduct headfire knockdown in an attempt to slow
headfire development and spread;
Aerial incendiary operations available during large fires to burn out significant areas of unburnt
fuel within the containment lines to reduce spot-over potential;
Maintaining a rapid initial attack ground capacity to contain spot-fires;
Multi-agency coordination of units, as well as integration of out-of-area resources (with no local
knowledge) into fire operations;
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Effective communications network management that can provide effective inter-agency coverage
across large fire areas, with difficult topography;
Capacity to capture, interpret and use linescan imagery, particularly for locating fire movement at
night when visual reconnaissance from low-level aircraft cannot be undertaken;
Flexible incident management structures and operating practice to sufficiently deal with hightempo periods when Divisional Commanders in the field may need to make and rapidly implement
tactical decisions involving backburning and burning-out operations; and
Well practiced planning and logistical support to establish and support long-duration field
operations.
1.8
The Potential Effects of Climate Change on Fire Risk Factors
In section 1.4, a range of plantation fire risk factors were identified. In this section, the manner in which
climate change may affect each of the identified risk factors is discussed.
1.8.1
Sensitivity to fire
Sensitivity to fire of each plantation species is a function of each species traits and adaptations
(controlled by genetics). Climate change is highly unlikely to have any impact on fire sensitivity as
changes would be driven by genetic changes (through adaptation or modification). Adaptation processes
take place over several generations, which is much longer than the time period of this study.
1.8.2
Plantation fuel and fire characteristics
Fuel loads
The mechanism through which climate change could bring about changes in plantation fuel quantity is
from changes in plantation production (growth rates) such that the amount and timing of litter deposition
is altered. Recent Australian modelling studies of the potential response of plantations to elevated CO 2
levels (Battaglia et al. 2009) concluded that:
Plantation production changes at particular sites will depend upon the relationship between the
current site climate and species optima and other site attributes such as fertility that will determine
the ability of species to benefit from changing [CO2] conditions;
Without a significant benefit to production from elevated levels of atmospheric CO2 and unless
adaptation options are explored, production in some regions will decrease, potentially markedly if the
predicted increases in number of hot-dry days either directly through damage or death, or indirectly
through pest attack further decreasing production; and
If plantation species are able to maintain increased net photosynthetic rates under elevated CO 2
levels productivity in many regions is forecast to increase. Increases in cool wet locations are
forecast to be marked.
As a potential consequence of increased CO 2 fertilisation effects, increases in fuel quantity at the
plantation scale are not likely to change by any measurable degree. What may change, and probably
only incrementally, is the timing of litterfall onset (if growth rates increase, crown closure may occur
earlier (Pritchard et al. 1999)) and the timing of litter deposition and decomposition reaching equilibrium
state may occur earlier. The impacts of such fuel changes on fire characteristics are likely to be
negligible.
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Fuel moisture
As fuel moisture content is a key determinant of fire behaviour (and of difficulty of fire suppression in
forests), changes in annual rainfall and seasonal rainfall patterns may have significant effects on fire risk
by altering the length and timing of periods when fuels will sustain fire spread, and the amount of fuel
available to burn (which directly influences rate of spread (linear function) and intensity (non-linear
function)). Additionally, changes in evaporation could amplify fuel moisture changes further.
At the inter-annual and seasonal time scales, fuel moisture is strongly correlated with soil moisture. In fire
danger rating systems, indices of soil moisture or drought (Drought Code, Soil Dryness Index (SDI), and
Keetch Byram Drought Index (KBDI)) are used to account for seasonal changes in fuel moisture,
particularly in coarse fuels and the mid to lower profile of surface fuels.
Climate change studies that consider changes in soil moisture can be instructive for considering potential
changes to seasonal fuel moisture. From a fire risk perspective soil moisture projections are superior to
using rainfall projections because soil moisture takes into account both rainfall and evaporation.
In a recent study of the potential impact of climate change on the nature and frequency of drought (and
exceptional circumstances payments) Hennessy et al. (2008) considered climate change projections for
soil moisture. They examined climate records from 1957 to 2006, finding that for NSW, Victoria and
Tasmania, years of exceptionally low soil moisture (lowest 5% of records) occurred in 1968, 1983 and
2003 and were immediately preceded by years of exceptionally low rainfall. These years correlate with
the very worst of bushfire seasons to have occurred in south-eastern Australia during the study period. In
1967 the worst bushfires in Tasmania’s history occurred, and in 1968 severe fires caused widespread
damage over much of the eastern part of NSW. In 1983, severe fires occurred across SA, Victoria and
southern NSW, including the ‘Ash Wednesday’ fires, with major plantation losses in all of those states. In
2003 an extended fire season with severe fires was widespread in Australia, with major plantation losses
in Victoria, the ACT and narrowly averted in NSW.
Hennessy et al. (2008) modelled climate projections (using 13 climate models found to work acceptably
well in the Australian region) and using the A1B emission scenario. Their mean range projections
indicate that years of exceptionally low soil moisture will occur more frequently by 2030, particularly in
Victoria, Tasmania, and southern SA and WA. At the higher end of their range of projections, years of
exceptionally low soil moisture are projected to occur about twice as often (relative to the 1957 – 2006
average) in most regions and almost four times as often in south-west WA.
Based on these projections, by 2030, all plantation regions examined in this study could expect to
experience severe fire seasons more often and potentially at twice the frequency previously experienced,
and potentially even more frequently in WA. Given the high correlation between years of exceptionally
low fuel moisture and large plantation loss events from uncontrollable fires in forested landscapes, it
would be reasonable to expect an upward trend in large plantation fire loss events.
1.8.3
Vegetation cover and condition in agricultural landscape areas
As discussed in section 1.6.3, vegetation cover and condition within a landscape is one of the most
important factors influencing fire risk. In general, fires spreading in forests and scrub are more difficult to
control than fires of equivalent proportions in grassland. They require greater resourcing and time to
control, and can breach containment lines much more readily. Grasslands which are green or grazed
short in summer provide the least difficult conditions for fire control. Landscape areas previously cleared
of woody vegetation for agricultural use are often maintained in their open condition by agricultural land
management practices such as grazing and cropping.
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Accordingly, if within a landscape there is a significant shift in land use practices leading to land cover
change from grass (or annual crops) toward more woody vegetation such as scrub or forest, escalation
in fire risk for nearby plantations may occur.
Higher rainfall areas
In some areas (particularly those of higher rainfall along the coast and ranges) and in the sustained
absence of grazing, woody vegetation can become re-established, within relatively short timeframes. In
theory, if climate change were to impact the economic viability of existing agricultural land management
practices in such areas, land management practices may change and depending on the their nature,
changes in land cover, particularly the extent of woody shrub and tree cover may result. In relation to the
effects of climate change on land use change, Dunlop and Brown (2008) have suggested:
Climate change, including changes in CO 2, temperature, frost and the seasonality, amount and
variation in rainfall, are likely to lead to changes in productivity of agriculture (including grazing on
rough and improved pastures, broadacre cropping, semi-intensive cropping, and horticulture) and
forestry which will almost certainly lead to significant land use changes. There will be productivity
increases in some areas (leading to expansions in agriculture) and reductions in others (leading to
contractions), and changes in relative productivity (leading to switches between crops, cropping
systems and cropping seasons). Many of these changes in land use will have impacts on
biodiversity (Dunlop and Brown pp101).
In practice, the general response of agricultural landowners to periods of lower rainfall or greater
seasonal rainfall variation and extremes, is to shift from more to less intensive grazing regimes, and /or
from sustained set stocking regimes to intermittent regimes whereby landowners get out of stock
ownership (reduce or dispose of stock altogether) and shift to leasing or stock agistment practices
(Brown, P.B. 2010, pers. comm., 12 August). The overall result is not that grazing is ceased altogether,
but the patterns of grazing are altered, hence changes in land cover driven by agricultural economics are
not likely to occur quickly and may not be significant by 2030.
Potentially a more likely driver of land cover change in the higher rainfall areas of the coast and ranges is
increasing occupation of rural land areas by owners who make their income through off-farm work, and
have little need for on-farm income (sometimes referred to as tree-changers). ‘Tree-changers’ typically
move onto smaller rural properties, with many removing grazing and promoting regeneration of native
species on formerly cleared areas. Demographic change trends in higher rainfall areas along the coast
and ranges therefore may be more significant than climate change and agricultural economics in
influencing land cover changes.
Low rainfall areas
Paradoxically, in lower rainfall areas inland, agricultural practices have historically promoted woody shrub
cover development (usually by unpalatable ‘woody weed’ species), due to grazing removing grass cover,
thereby restricting the frequency and extent of fires that prior to European settlement were a limiting
factor on shrub development.
If climate change were to impact the economic viability of current agricultural land management practices
in semi-arid areas, changes to land cover and therefore fire regimes may occur. Dunlop and Brown
(2008) suggest that in semi-arid areas, pastoralism may decline and even be abandoned in some areas.
In theory, in semi-arid agricultural areas, a shift to lower stocking or more intermittent grazing may result
in increased frequency of large fires.
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Fires in these areas are carried across the landscape by cured grass cover, usually following seasons
with above average autumn /winter /spring rainfall which generates a higher abundance of grass cover
than the land owners’ domestic stock herds and other grazing animals can consume. In practice, one of
the prevalent drought management strategies of pastoralists in southern areas is to agist stock from
south to north, particularly when drought is declared and government subsidies for stock transport are
available for moving stock. Under this general scenario semi-arid pastoral landscapes are likely to
continue to have low fire frequency and risk during drought periods. However, when seasonal conditions
are good in both the northern and southern inland, the financial incentives to move stock are diminished,
and continuous grass fuels may persist in the landscape for longer periods than have been the case
historically. This may result in an increase in fire frequency. However, for land cover generated fire risk
factors to change appreciably, relatively widespread changes to grazing practices would be required,
which under current trends appear unlikely to occur.
1.8.4
Vegetation condition changes in forested landscape areas
In theory, changes in vegetation condition in forested areas could alter fuel characteristics and potentially
therefore fire risk factors. In areas where climate drying is projected, gradual changes in the distribution
of forest and woodland vegetation types may occur. Dunlop and Brown (2008) discuss rates of Australian
forest distribution shifts in the context of whether forests can shift their distributions fast enough to keep
track with future bioclimatic habitat shifts. Historical analysis of tree distribution shifts in the northern
hemisphere estimated rates of up to 2 km per year, however other studies suggest much slower rates of
between 0.1 to 0.5 km per year (Iverson and Prasad 1998). Markgraf and McGlone (2005) found there is
no evidence for forest distribution shifts being widespread among Australian species in response to
warming after the last glacial maximum.
It would seem evident that fuel characteristic changes brought about by forest distribution shifts are
unlikely to be an issue over decadal time frames.
Gradual changes in vegetation form may occur, with change direction trending from the wetter range
stand formations to dryer range formations (e.g. from forest toward woodland structure). In areas
projected to get wetter, trend directions may be from more open dry forest stand formations to taller and
denser forest formations. Changes in composition, in both the overstorey and understorey species, may
also occur.
Changes in the structure and composition of vegetation formations could take many decades, but could
be accelerated by altered fire regimes.
The combination of Eucalypt canopy decline and thinning during severe drought stress, and CO 2
fertilisation effects favouring shrub productivity over grass productivity could lead to vegetation
thickening, especially in areas where fire frequencies are kept low by fire suppression effectiveness. If
CO2 fertilisation leading to vegetation thickening were taken in isolation of other factors, one might
anticipate increased fuel load and vertical structure in forests.
However, climate change modelling undertaken by the Bushfire Cooperative Research Centre indicates
that in southern Australia we can expect that the average summer temperature will increase, there will be
an increase in the number of Very High and Extreme fire danger days and changes in seasonal rainfall
patterns. The likely outcome of these changes is more frequent fire regimes (Cary, 2002; Bushfire CRC,
2010). More frequent fire regimes should, in theory, result in lower landscape fuel loads and more open
vegetation structure. Thus the CO 2 fertilisation effects and increased frequency fire regime effects are
acting in opposite directions in terms of landscape fuel load impacts.
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It is not clear what the impacts of climate change will be on landscape fuel loads, with the end outcomes
likely to be the result of numerous and complex interactions.
1.8.5
Climate and weather
In a study of projected climate change impacts on bushfire weather in south-east Australia, Lucas et al.
(2007) concluded:
In general, fire weather conditions are expected to worsen. By 2020, the increase in cumulative FFDI
is generally 0-4% in the low scenarios and 0-10% in the high scenarios. By 2050, the increase is
generally 0-8% (low) and 10-30% (high). The largest changes are expected in northern New South
Wales. Little change is expected in Tasmania. With this increase in cumulative FFDI, a larger
number of days with a Fire Danger Rating of ‘very high’ or ‘extreme’ are also expected. The number
of ‘extreme’ fire danger days generally increases 5-25% for the low scenarios and 15-65% for the
high scenarios. By 2050, the increases are generally 10-50% in the low scenarios and 100- 300% for
the high scenarios. The seasons are likely to become longer, starting earlier in the year (Lucas et al.
2007, p48).
The daily weather conditions have a substantial influence on bushfire risk. Fire danger rating systems
around the world are sensitive to changes in weather variables; particularly wind speed, relative humidity
and temperature (the latter two variables having influence through their governing effects on fine fuel
moisture). Fire danger rating systems are essentially scales representing the level of difficulty of fire
suppression. At the higher ratings (Very High to Catastrophic) fires starting in fire prone forests will very
quickly reach proportions beyond the capacity of modern fire suppression technology to control. At lower
ratings (Low /Moderate to High), fire control efforts in areas with adequate fire suppression capacity are
usually successful in containing fires to relatively small areas. This has been the experience across
Australia’s plantation industry – all recorded major plantation fire loss events have occurred on days
when the FDR has reached the Very High to Catastrophic range).
Accordingly, an increase in the number of days during which the FDR reaches Very High to Catastrophic
might logically be expected to increase plantation fire risk and losses.
Somewhat disturbingly, Lucas et al. have identified that in some areas the recent trends in the
occurrence of severe fire weather conditions are already at levels exceeding the upper range predictions
for 2050. This raises the prospect that the modelled projections may be too conservative.
The logical flow-on effects of the worsening bushfire weather trends are that:
The increased occurrence of severe fire weather in which successful initial attack efforts have a high
probability of failure are likely to result in an increase in numbers of large intense fires in the
landscape. Plantation mangers seeking to improve their prospects of initial attack success may need
to consider a range silvicultural treatments and in-plantation fuel management options not previously
considered; and
Plantation managers will need to give serious consideration not only to how they manage initial attack
operations, but also to how they will respond to contain damage by large intense fires given these
have an increased likelihood of occurrence in the future.
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1.8.6
Ignition issues
While lightning is a major cause of fires in forest and woodland areas, and particularly of multiple forest
fire scenarios, research on climate change implications for lightning occurrence across southern
Australia is inconclusive (Goldammer and Price, 1998), with current climate models unable to capture
thunderstorms (CSIRO 2007a).
Climate change impacts on ignition issues will principally be through any climate associated changes in
demographics, as people are the leading cause of fires. Climate change may affect demographics in a
range of ways. For example, in rural areas where economic returns from agriculture are projected to
become unviable or more marginal in some dryland agriculture areas, recent population decline trends
may be exacerbated.
In theory it is logical that less people should translate to less human ignition sources. However, other
factors come into play. Areas where agriculture becomes unviable or marginal are unlikely to have
sufficient fuels in the landscape to support large fires, unless there is land abandonment on a significant
scale giving rise to land cover changes (discussed in Section 1.7.3). Smaller local populations are also
likely to result in reduced participation in volunteer bushfire brigades so that even if fewer fires start, their
suppression probability may be lowered.
In higher productivity areas in cool temperate, moist sub-tropical and Mediterranean agro-climatic zones
where most plantations are situated, potentially significant population increases are more likely to be
experienced near existing population centres. Population increase trends may be largely independent of
climate change impacts. However, declining agricultural profitability trends over recent decades,
particularly impacting smaller scale businesses, have resulted in well documented consolidation trends.
Climate change impacts in areas of dryland agriculture are likely to continue or exacerbate this trend
(Lane, J. 2010, pers. comm., 3 August).
The likely result is that for dryland agriculture dominated areas where population increases are projected,
the increases are most likely to be focussed around existing population centres, with negligible increases
or population decline experienced in the broader agricultural landscape.
1.8.7
Fire suppression capacity issues
Climate change impacts on fire suppression capacity will primarily be indirectly, through impacts on
demographics and land use change.
Fire suppression capacity in rural areas is heavily dependent on volunteer rural bushfire brigades.
Studies of recent volunteer bushfire brigade capacity trends, and how these might alter in the future,
suggest a declining trend. The Bushfire Cooperative Research Centre (Bushfire CRC 2008) frames the
issue as follows:
During 1995-2003, total volunteer firefighter numbers across Australia declined appreciably,
because of complex economic and demographic changes in Australian society (McLennan and
Birch, 2005). While most agencies report that these declines in total numbers appear to have been
halted, and in some cases reversed, there is little room for complacency. There is concern about
likely negative impacts of climate change in large areas of Australia on future volunteer numbers
(Office of the Emergency Services Commissioner, 2008): an increase in the frequency of severe
weather events plus generally drier conditions will likely result in more frequent large fires, and thus
greater demands on volunteers’ time. Furthermore, it seems likely that economic uncertainties and
concerns (such as rising fuel costs) may deter many from volunteering with fire agencies in the
future (McLennan, 2008).
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An additional and important factor to consider is how rural volunteer bushfire brigade capacity is utilised
during major fire events and what, if any, impacts this might have on plantation fire risk. Sustained
growth of Australia’s population has seen a most significant expansion of communities and built assets in
fire prone landscape areas. This has translated in steady growth in the number of people at risk from
bushfire impact. The vast majority of those at risk live and /or work at the margins of population centres
such as cities and towns. All fire and emergency services have as their absolute highest priority the
protection of human life. Typically, the result is that when bushfires develop and threaten human
population centres, a very high proportion of the available suppression forces are tasked to community
protection, and are not available for plantation firefighting or protection.
Projected demographic trends suggest that the numbers of Australians living in high bushfire risk
situations (at the urban bushland interface around towns and cities, or in residential-bushland intermix
areas) is certain to continue as a steady increase. With volunteer firefighter numbers struggling to be
maintained or declining, it is reasonable to assume volunteer firefighting capacity available for tasking to
plantation protection or firefighting during fire events to have reduced availability in the future.
1.9
Summary
The likely effects of climate change on each of the key plantation fire risk factors have been considered.
Not all impacts will operate in the same direction, with the risk profile of some factors improving,
deteriorating for others, and still uncertain for some factors. Due to the uncertainties involved and the
influence of processes other than climate change it is difficult to gauge what the aggregate effect of these
factors will be. However, the following section attempts to synthesise and summarise the likely future
changes to plantation fire risk profiles:
The fire risks for which the direction of change (positive or negative) is uncertain or negligible
are:
Plantation fire sensitivity (negligible);
Plantation fuel quantity and arrangement (negligible);
Native vegetation condition changes (uncertain). The impacts of CO 2 fertilisation and rainfall
reductions may act in opposite directions. The impacts of fire suppression and increasingly frequent
fire regimes may act in opposite directions. Other issues of climate impacts on forest health and
structure, and of weed species expansion add further complexity;
Native vegetation range and distribution changes (incremental);
Landscape scale land cover changes across dryland agricultural lands (incremental and patchy).
Broad scale cessation of grazing on marginal lands is less likely than reductions in grazing intensity
and shifts to more intermittent grazing patterns which may not appreciably alter land cover; and
Fire ignition across the broader agricultural and public land components of landscapes (negligible).
Population increases are unlikely to be even across the agricultural landscape; more likely they will
be concentrated in and around existing population centres.
The fire risk factors which may improve with projected climate changes are:
Fire regimes in native bushland may become more frequent, which may have the effect of reducing
the proportion of the landscape carrying very high fuel loads; and
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Climate change adaptation responses and policy changes by public land management agencies may
result in increased use of prescribed burning, which would result in reducing the proportion of the
landscape carrying very high fuel loads.
The fire risk factors which are likely to deteriorate with projected climate changes are:
The occurrence of severe fire weather is likely to be more frequent exposing plantations to more days
of Very High and Extreme fire danger which are closely correlated with major plantation fire events;
More frequent, widespread and severe drought resulting in an extension of the period when
plantations are in a fire prone and vulnerable condition, and the proportion of plantation fuels
available to burn is higher more often;
Vegetation cover changes in areas experiencing ‘tree-change’ and ‘sea-change’ trends. Native
vegetation being re-established on sub-divisions of cleared land formerly used for agriculture; and
Suppression capacity (mostly manpower) reductions across dryland agricultural areas as populations
in those areas decline and age.
The negatively impacted risk factors tend to be on the factors with the greatest influence on overall
plantation fire risk, and outnumber the positive factors. Accordingly, across plantation regions where
rainfall reductions are projected, plantation fire risks are likely to increase as a result of climate change,
and in some areas (particularly those with projections for relatively high reductions in annual rainfall) the
level of increase in fire risk may be substantial.
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2.
Regional Plantation Profile
2.1
Location
The Central Tablelands Plantation Region is located on the western side of the Great Dividing Range
approximately 150 kilometres west of Sydney. The National Plantation Inventory Region extends from
Dunedoo in the north, westwards to Wellington and Eugowra, south to Crookwell, then eastern and north
through Boorowa, Crookwell, Kanangra Walls, Katoomba and Rylstone (Figure 2-2). The main localities
within the Region are Orange, Bathurst, Oberon and Lithgow.
The study area selected for this study incorporates the majority of the softwood plantation resource of the
National Plantation Inventory Region, but excludes the small area of hardwood plantation. It falls within
the central section of the National Plantation Inventory Region within six NSW local government areas
(Figure 2-2, Table 2-1).
Table 2-1
Local Government Areas within the study area
Local Government Area
Size (hectares)
Oberon Council
362,394
Bathurst Regional Council
382,174
Orange City Council
28,367
Cabonne Council
602,316
Blayney Shire Council
152,463
Lithgow City Council
456,406
2.2
Plantation Estate
Plantations have been established in the Central Tablelands for a considerable period, with some third
rotation plantation blocks. The major plantation forest clusters are on the Oberon Plateau extending
south-west to Burraga (66% of plantation within the study area), at Sunny Corner and east to Lithgow
(18%), and around Mount Canobolas. Smaller blocks of plantation are established north of Lake
Wyangala, on the Newnes Plateau and east and north of Orange (Figure 2-2). Hardwood plantations are
restricted to small demonstration and research plots primarily in the western part of the Region, and
outside the study area.
The majority of plantation resource within the study area is Pinus radiata (>99%) comprising 80,053
hectares (Table 2-2). The area planted remains relatively stable with little expansion between 2005 and
2009 (Table 2-3). The majority of the plantation is either first (72%) or second rotation (27%) (Table 2-4),
and across a range of age classes (based on Forests NSW data) (Figure 2-4). Plantations are first
thinned at approximately 21-22 years, and second thinned at approximately 28 years.
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Source: DAFF 2010
Figure 2-1 National Plantation Inventory Region location map
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Table 2-2
Study area statistics
(hectares)
Bathurst
Pinus radiata
3639
Softwood
untyped*
1333
Blayney
Cabonne
Lithgow
Oberon
Orange
8722
10609
41414
566
1287
107
11968
14,923
13
19
150
181
10022
10753
53532
228
Other
Softwoods**
Total
4971
228
566
Total
64,949
80,053
* ‘Softwood untyped’ most likely Pinus radiata. **Other softwoods include Pinus caribaea, P. contorta, P. laricio, P. muricata, P.
pinaster, P. ponderosa, P. taeda and Pseudotsuga sp.
Table 2-3
Central Tablelands National Plantation Region statistics
2005
2009
Softwoods
79,406
80,474
Hardwoods
984
80,390
Total
%
2005/09
Change ha.
% of total
1.3%
1,068
98.79%
984
0.0%
0
1.21%
81,458
1.3%
1,068
100.00%
Source: DAFF (2006), DAFF (2010)
Table 2-4
Rotation
Study area rotation
Bathurst
Blayney
Cabonne
Lithgow
Oberon
Orange
Total
1R
4340
228
5920
6017
40635
566
57686
2R
631
4094
4547
12812
22084
3R
0
8
189
85
283
10022
10753
53532
Total
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80053
37
Figure sourced from DAFF 2007
Figure 2-3 Forecast Plantation log supply (Softwood) – Central Tablelands NFIR
Source: Forests NSW 2008
Figure 2-4 Plantation age class and silvicultural condition
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Plantation ownership
The major plantation manager in the study area is Forests NSW, a public trading enterprise of the NSW
Government, falling under the NSW Department of Industries and Investment. Forests NSW manages
more than 80% of the plantation estate, with private holdings generally unconsolidated and in decline as
older plantations are reaching clear fell age and not being re-established. In April 2010 the NSW
Government announced the purchase of the plantation assets of TEPCO within the study region.
2.3
Regional Plantation Forecast
This section uses information from Australia’s Plantation Log Supply 2005 – 2049 (DAFF 2007). This
information, prepared by the National Plantation Inventory, forecasts the future supply of sawlogs and
pulpwood from plantations. The information in this report is based mainly on data on plantation area for
2005 published in the Australia’s Plantations 2006 report (DAFF 2006). Other sources of information
include various published sources as identified.
2.3.1
Assumptions of Australia’s Plantation Log Supply 2005 – 2049
Most of the forecasts in the Australia’s Plantation Log Supply 2005-2049 report (DAFF 2007) were
derived from data provided by the owners and managers of large plantation estates. Discrepancies and
inconsistencies were clarified with the owner or manager.
The forecasts are based on the assumption that harvested areas will usually be replanted with the same
type of plantation. This may not be the case however where harvested plantations are not replanted,
some softwood plantation sites are replanted with hardwoods and some hardwood plantation sites are
replanted with softwoods.
These factors have been allowed for in a few regions, but only where there is an adequate understanding
of likely changes.
Supply forecasts assess the area of plantations by year of establishment, as well as the assumed
production period and growth rate for a given type of plantation. Variations in the area planted from year
to year result in variation in forecast supply. Market demand will determine the actual volumes that are
harvested at a particular time and plantation managers will adjust silviculture, scheduling and operational
management accordingly. This usually leads to a smoothing of supply over time.
Potential changes in the productivity of future rotations have not been considered in the forecasts
developed by the National Plantation Inventory (DAFF 2007).
2.3.2
Central Tablelands and study area plantation forecast
Existing extent and recent trends
The Central Tablelands is a significant softwood sawlog-producing region, with an estimated production
of 7% of the national softwood sawlog total in 2010, and provides a significant contribution to softwood
pulpwood supplies. The region also produces particleboard and fibreboard.
Log supply for the Central Tablelands NPI Region is forecast to remain steady until 2050 with an annual
average log supply of 708,000 cubic metres of sawlog (Figure 2-5) and 576,000 cubic metres of
pulpwood (Figure 2-6). Forecast log supply and timber supply commitments are shown in Table 2-5, with
Forests NSW maximum commitment under present wood supply agreement of 1.295 million tonnes
(Forests NSW 2008). This does not include private supply, estimated to comprise 20% of the total supply
in 2008 (Forests NSW 2008). The plantations of the region have the potential to supply up to 1.5 million
tonnes annually (Oberon Council 2010).
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Figure 2-5 Forecast plantation softwood sawlog supply by region (DAFF 2007)
Figure 2-6 Forecast plantation softwood pulpwood supply by region (DAFF 2007)
Table 2-5
Annual plantation forecasts and Forests NSW wood supply commitments
Volume (‘000 tones)
Forecast 2010-2049
20 yr commitment
(minimum)
20 year commitment
(maximum)
Sawlog
708
490
645
Pulplog
576
486
650
Source: DAFF 2007; Forests NSW 2008
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The main timber processing facilities are located in Oberon where Carter Holt Harvey, in a joint venture
with Boral, operate a sawmill and medium density fibreboard and particle board factory and panel plant.
A door skins plant is also located in Oberon. Smaller scale facilities are located in Blayney (Blayney
Treated Pine), Bathurst (Allied Timber) and Burraga (Pacpine) producing a range of specific sawn and
treated products. The plantations also supply pulp timber outside the region to the Visy Pulp and Paper
Mill at Tumut.
Potential impacts on future supply
The increase in plantation investment across Australia in the last decade has been primarily in hardwood
plantations, driven largely as a consequence of taxation arrangements (DAFF 2007), and occurring
outside the Central Tablelands study area.
Within the study area the rate of plantation establishment has historically been contingent on the
availability of suitable lands, funding sources, and NSW and Commonwealth policy and legislation
(Forests NSW 2008). It is not anticipated that there will be a major change to the plantation profile within
the Central Tablelands, with Pinus radiata is expected to remain the dominant species. However it is
anticipated that some of the private pine currently nearing clearfall will not be established back to
plantation.
If a National carbon pricing system is introduced that permits carbon offset plantings it is anticipated that
hardwood plantations may be established in the western part of the NPI Region, in the headwaters of the
Lachlan and Macquarie catchments (to the west of the study area). The species planted as carbon offset
are more likely to be fire resistant species that can persist locally but also have higher carbon storage
potential (such as Eucalyptus cladocalyx, E. sideroxylon, E. melliodora and Corymbia maculata (GHD
2009)) than the more fire sensitive hardwood plantation species widely established for timber and fibre
production.
2.4
Summary
Significant changes to the plantation profile are not forecast in area and silvicultural treatment;
however the area of private pine may decline as it nears clearfall age.
Pinus radiata will remain as the dominant species, supporting significant processing facilities. As a
fire sensitive species, maintenance of mitigation measures is required to reduce fire risk.
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3.
Regional Climate Trends and Forecasts
3.1
Current Climate
The study area has a temperate cool-season wet climate (Stokes and Howden 2010) with mild to hot
summers. Average annual rainfall varies across the study area, generally grading from east to west
(1000m – 600m) (Figure 3-1) and is broadly associated with topography (Jenolan Caves (964 mm),
Oberon (842 mm), Bathurst (583 mm) Orange (926 mm), Canowindra (599 mm)). Seasonal rainfall is
distributed fairly evenly, though autumn is often drier than other seasons.
The annual average temperature is greatest in the western part of the study area and cooler in the east
(Figure 3-2), with average maximum January temperatures approximately 24–28°C (Oberon 24°C,
Orange 26°C, Bathurst 28°C) (BoM 2010).
Figure 3-1 Study area mean annual rainfall
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Figure 3-2 Study area mean annual temperature
3.2
Regional Climate Projections
An overview of the expected regional impacts of climate change the each study area under different
scenarios was undertaken. This analysis was guided by methodology for considering climate change in
natural hazard risk assessments (Department of Community Safety 2010), using projected estimates of
temperature, rainfall and evaporation change as well as changes in the number of days recorded at over
35°C. These projections are based on data presented in Climate Change in Australia – Technical Report
(CSIRO and BoM 2007). Greenhouse gas emissions scenarios are based on the Intergovernmental
th
Panel on Climate Change 4 Assessment Report (IPCC 2007) and are summarised in Climate Change
in Australia (CSIRO and BOM 2007).
For 2030 only the A1B (medium) greenhouse gas emissions scenario projection was used as there is
very little variation from other emissions scenarios over this period. The A1B (medium) scenario is one
in which population expands rapidly, peaking in the mid-century and declining thereafter. Very rapid
economic growth is mirrored by the development of new and more efficient technologies, and global
solutions.
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For 2070 the A1B (medium) and A1FI (high) scenarios are compared. The A1FI scenario differs from the
A1B scenario, in that A1F1 is fossil energy intensive.
Climatic data for the study area, based on data sourced from Bathurst Agricultural Station (elevation
713m, Data: 1909 to current), was analysed to compare recent data with climate change projections
(best and worse case scenarios). This weather station satisfies the Bureau of Meteorology reference
period (1961-1990) climate benchmarks. This period is adopted as a benchmark reference period by
modellers, including the World Meteorological Organisation, because it is not associated with
anthropogenic changes in the chemical composition of the atmosphere, as the following decades have
been.
3.3
Trends
Mean annual temperature increased by 0.4°C between the 1966-1990 reference and 1991-2008 periods.
This increase appears to be trending towards the best estimate of a 0.8°C increase in 2030 (Table 3-1).
Rainfall has decreased by 6.2% since the reference period. This decrease may be trending towards the
projected worse case scenario of a 7.5% decrease by 2030 under the A1B scenario (Table 3-1).
The seasonal distribution of rainfall has changed between the reference period and 1991-2008
observations (Table 3-2). The first half of the year has become drier, with a 0.4% decrease in summer
rainfall followed by a 16.9% decrease in autumn rainfall. Increased rainfall in the second half of the year
is evident as a 5.5% increase in winter and 7.7% increase in spring rainfall. The autumn decrease of
16.9% significantly exceeds projected decreases for both 2030 and 2070. Summer rainfall is also
projected to increase between 20-50% by 2050 and decrease by 10-20% in winter (DECCW 2010).
Potentially this projected summer increase may be linked to increased tropical rainfall in north-western
Australia, and the south-east passage of residual tropical systems.
Mean days over 35°C have increased by 46.2% between the reference period and 1991-2008, however
it is important to note that available data for the regional study area was incomplete and may limit the
accuracy of calculated means. Projected estimates for Bathurst (under the A1B scenario) indicate the
number of mean days over 35°C to reach up to 11 days per annum by 2030 and 7 days per year by 2070
(Table 3-1).
Pan evaporation has increased by 23.7% between 1966-1990 and 1991-2008 and is trending at a much
higher rate than projected estimates.
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Table 3-1
Central
Tablelands
Central Tablelands climate forecasts
Annual
Reference Periods
1961-1990
1991-2008
Change
2030 A1B
Projected best1
estimate
2070 A1B
Projected worse
case scenario
Projected best1
estimate
2070 A1FI
Projected worse
case scenario
Projected best1
estimate
Projected worse
case scenario
Temperature
13.3 °C
15.8°C
(19651990)
16.2°C
0.4°C
0.8°C
1.25°C
3°C
4.5°C
2.75°C
3°C
Rainfall (mm)
633.7
658.3
617.5
6.2%
3.5%
7.5%
7.5%
30%
7.5%
30%
1350
1002.4
(19661990)
1314.4
23.7%
3%
by 6%
by 10%
by 14%
by 6%
by 10%
4.5
2.9
(19661990)
5.4
46.2%
Pan
evaporation (in
24 hours
before 9am)
Mean days
>35°C per
annum
4-11 mean days
-
1-7 mean days
-
-
-
Source: BoM 2010f/IOCI 2004 /IPCC 2007. Best estimate based on 50th percentile. Worse case scenario based on 90th percentile for temperature and pan evaporation and 10th
percentile for rainfall
Notes:
1
2
3
‘Best estimate’ does not mean best case scenario – it is the estimate, from within the range of possibilities, considered to be the most likely to eventuate
The 90th percentile value means that there is a 90% chance temperature and pan evaporation sensitivity is less than this value , but a 10% chance it is
even higher than this value (ie hotter than this value).
The 10th percentile value means that there is a 10% chance rainfall sensitivity is less than this value (ie even less rainfall than this value), but a 90%
chance it is higher than this value.
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Table 3-2
Rainfall seasonality
Summer
Autumn
Winter
Spring
1961-1990
206.15
142.9
132.69
172.47
1991-2008
205.14
118.7
140.85
186.95
Change
3.4
Decreased by 0.4%
Decreased by 16.9%
Increased by 5.7%
Increased by 7.7%
Summary
The implications for plantation forestry fire risk are:
The local climate has become warmer and drier, with decreasing mean annual rainfall evident
between reference period and 1991-2008 observations;
Rainfall seasonality has changed between reference period and 1991-2008 observations, resulting in
drier summer and autumn months (corresponding with the bushfire season) and wetter winter and
spring months (corresponding with growing periods);
Projections for rainfall seasonality predict increased spring and summer rainfall, stable autumn
rainfall and reduced winter rainfall;
Increasing temperatures and reduced rainfall may extend the fire season, including an earlier start;
and
Reductions in autumn rainfall may extend the current window available for prescribed and top
disposal burning, though reductions in fuel moisture may increase control difficulty.
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4.
Regional Land Use Changes
4.1
Land Use
More than half of the Central Tablelands study area is occupied by grazing modified pastures (55% of
total land use), with most of this occurring in the Cabonne and Bathurst LGAs. Table 4-1 provides further
details of the key land uses in the area.
Table 4-1
Land use in the Central Tablelands study area, 2005
Land use
Area (ha)
% of study area
Grazing modified pastures
1,095,396
55.2
Nature conservation
325,833
16.4
Other minimal use
222,639
11.2
Cropping
102,713
5.2
Plantation forestry
91,627
4.6
Production forestry
77,222
3.9
Other
67,878
3.4
Source: DAFF Spatial Data
4.1.1
Spatial distribution of land use and management
A large proportion of the fuel landscape within the study area has been cleared for agriculture purposes
such as grazing and some cropping, with smaller areas established for viticulture, orchards and hobby
farms. Sub-division of land for hobby farms has occurred round the main growth centres. Oberon’s
1
proximity to Sydney is encouraging small acreage subdivisions . The development and operation of
these properties has provided a substantial injection to the regional economy; in 2003/04 these impacts
were estimated at $5.0 million and $1.4 million in gross output respectively (Western Research Institute,
2005).
The land adjoining plantations of the study area is predominantly dryland agricultural enterprises
(incorporating small acreage subdivisions), and conservation or natural forests. Natural environments
dominate the eastern part of the study area, and are associated with more rugged topography of the
Great Divide. These natural areas include catchment lands, National Park, and native production
forests. The majority of plantation forestry is undertaken in Oberon (62% of total plantation forestry), in
the south-east part of the study area. Primary land use within the study area is shown in Figure 4-1. A
reasonable level of built infrastructure is present within and adjoining plantation areas. This includes
assets associated with mining (around Lithgow and Orange), power (Lithgow), transport, water and gas
supply, and urban and semi-rural business and residential development. Timber processing facilities are
located in Oberon.
4.1.2
Landscape vegetation cover and condition
Wetter types occur in the eastern part of the study area that forms part of the Great Divide, including wet
and taller dry sclerophyll forests. Moving westwards annual rainfall declines and the native vegetation
grades into more open dry sclerophyll forest, woodland and grassland types. The distribution of
vegetation cover and condition within the study area is shown in Figure 4-2.
1
Small acreage is defined as properties between 2 to 40 hectares.
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4.2
Impact of Climate Change
The Central Tablelands study area is part of the Temperate Cool-season Wet Region. The projected
effects of climate change in this region are shown in Table 4-2. Climate change is expected to result in
increased temperatures, evaporation, and number of days over 35°C. Reduced water resources and
increased flood risk in the west of the region, are also anticipated. These climate effects are likely to
impact on existing land use in the region; in particular via reduced water availability for cropping and
horticulture, improved pasture growth for grazing, and increased forestry fire risk arising from reduced
rainfall and fuel moisture levels.
Table 4-2
Summary of regional climate change effects
Climate Trends
Forestry Trends
Landscape Trends
Temperate Cool-season Wet Region
Increased temperature
Increased evaporation
Increased number of days over
35°C
Decline in rainfall, particularly in
Spring
Slight decrease in water
resources in coastal areas
Moderate decrease in water
resources in inland areas
Increased flood risk to the east
Increased growth due to the
effects of CO2 fertilisation
Extension of growing season
associated with extended
warming period (where water is
not limited)
Decreased growing season
associated with extended
warming period (where water is
limited)
Decreased nutrient cycling and
forest productivity due to a
combination of increased
temperatures and decreased
rainfall
Reduced productivity in less
fertile soils and within the upper
climate thresholds
Increased pest damage
associated with extended
warming period
Increased fire risk due to
decreased Spring rainfall and
fuel moisture levels
Increased plant water demand associated
with increased and extended warming
periods
Irrigation practices may become more
opportunistic
Crop selection and management may
become more opportunistic
Winter crop yields reduced through
reduced irrigation supplies
Horticulture may become more viable in
cool areas, but may be limited by extreme
hot temperature in other areas
Cool areas may become suitable for
viticulture, with a change in varieties
Decreased horticultural and viticultural
pests and diseases
Irrigated dairy may be limited by reduced
water availability
Pasture-based dairy may benefit from
slight warming
Woodland extent may decline
due to changes in surface and
groundwater availability
Monitoring of the effects of
climate change on Eucalyptus
globulus, Pinus radiata required
to guide future planting
Regional impacts adapted and summarised from CSIRO 2010, CSIRO and BoM 2007, and IOCI 2004.
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4.3
Summary
The implications for plantation forestry fire risk are:
The combination of increased temperatures and days over 35°C, and reduced rainfall and runoff, is
likely to increase the level of fire risk;
Small acreage subdivision may encourage land that was previously grazed to be revegetated, or
lesser grazed, thereby increasing fuel loads. Sub divided allotments may also have increased
infrastructure (such as fences) that may impede access for initial attack. However, subdivision is
likely to boost the local population, which may improve the likelihood of early fire detection in
developed areas; and
Grazing and nature conservation areas, which tend to occur adjacent to plantations in the study area,
may also lead to increased risk:
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More than half of the study area is used for grazing. Several factors will influence the
degree of fire risk such as the extent of pasture growth, type of grazing system, stocking
rate, and the presence of an on-site property manager. For example during drought,
pasture is likely to be drawn down (thereby reducing fuel loads). However as livestock
numbers are reduced and seasonal conditions improve, pasture growth can out-strip
livestock demand and the fire risk is increased.
o
A substantial proportion of the study area is designated as nature conservation. The
management of conservation areas has a substantial influence on the degree of fire risk
(e.g. extent of undergrowth, whether the site is a national park). Management varies
according to site-specific objectives and it is difficult to project what these will look like
going forward.
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5.
Regional Demographic Changes
5.1
Population
The Central Tablelands study area is comprised of six LGAs and had a population of almost 115,000 in
2006. The region has experienced minor population growth (1.1% between 2001 and 2006). Bathurst
Regional and Orange account for almost two-thirds of the total population, as shown in Figure 5-1.
Cabonne
11%
Blayney
6%
Oberon
4%
Bathurst Regional
32%
Lithgow
17%
Orange
31%
Source: Australian Bureau of Statistics (2007)
Figure 5-1 Central Tablelands study area population, by LGA (2006)
Murphy (2002) suggests areas such as the Central Tablelands are likely to become part of the perimetropolitan regions of the major capital cities, as cities continue to grow. In this sense, inland areas like
the Central Tablelands would increasingly become sea-change localities and population growth would be
expected.
Similarly, the Western Research Institute (2005) reports of in-migration by retirees seeking a rural
lifestyle in Oberon.
5.2
Age
The median age of the Bathurst Regional and Orange populations is below the NSW average, however
in other LGAs such as Cabonne, the median age of the population is considerably higher (Table 5-1).
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Table 5-1
Median age, by LGA
LGA
2001
2006
Bathurst Regional
32
34
Blayney
37
39
Cabonne
39
41
Lithgow
37
40
Oberon
35
37
Orange
33
35
New South Wales
35
37
Source: Australian Bureau of Statistics (2007)
Around 30% of the study area population is aged 19 years or below, which is slightly higher than the
NSW average (Table 5-2).
Table 5-2
Study area population, by age category (2006)
Study area
% of total
NSW
% of total
0-19 years
33,600
29.5%
1,736,345
26.6%
20-34 years
20,483
18.0%
1,320,146
20.2%
35-49 years
23,660
20.8%
1,429,215
21.9%
50-64 years
20,613
18.1%
1,141,268
17.5%
65+ years
15,617
13.7%
901,717
13.8%
Total
113,973
100.0%
6,528,691
100.0%
Source: Australian Bureau of Statistics (2007)
5.3
Labour force and employment
Almost 94% of the study area labour force was employed in 2006, which is consistent with the NSW
average. Employment grew 4.3% between 2001 and 2006, which was slightly below the NSW average.
Employment in the Central Tablelands study area is quite diverse, with no single industry particularly
dominant. The largest number of people are employed in health care and social assistance, retail trade,
and manufacturing, as shown in Figure 5-2.
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Health care &
social assistance,
12%
Retail trade, 12%
Other, 42%
Manufacturing,
11%
Agriculture,
forestry & fishing,
7%
Education &
training, 9%
Public
administration &
safety, 8%
Source: Australian Bureau of Statistics (2007)
Figure 5-2 Proportion of employment, by industry (2006)
Around 7% of the working population (3,300 people) is employed in the agriculture, forestry and fishing
industry, which is more than double the NSW average. Over 90% of these work in agriculture, followed
by forestry and logging (4%).
Of the 5,300 people that are employed in the manufacturing industry, more than 15% of these work in
wood product manufacturing. Less than 1% of manufacturing industry employment is in pulp, paper and
converted paper products.
Industries that have experienced substantial employment growth between 2001 and 2006 include: public
administration and safety; mining; and health care and social assistance (Figure 5-3). There has been a
significant decline in employment in the wholesale trade; agriculture, forestry and fishing; and
manufacturing industries.
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P ublic
administratio n &
safety
32.2%
28.6%
M ining
Health care & social
assistance
-30%
18.5%
M anufacturing
-12.9%
A griculture, fo restry
& fishing
-13.0%
Wholesale trade
-22.2%
-20%
-10%
0%
10%
20%
30%
40%
Source: Australian Bureau of Statistics (2007)
Figure 5-3 Employment growth for selected industries (2001 to 2006)
5.4
Education
A summary of the level of non-school qualifications obtained by persons over the age of 15 years is
provided in Table 5-3. More than a third of the study area has obtained a diploma or higher level of
education, compared to about 45% in New South Wales.
Table 5-3
Level of non-school qualification (2006)
Study area total
Qualification
New South Wales
%
%
Postgraduate Degree
1,343
3.0%
161,905
5.7%
Graduate
Diploma/Certificate
983
2.2%
65,710
2.3%
Bachelor Degree
7,086
16.0%
632,835
22.2%
Advanced
Diploma/Diploma
5,329
12.0%
386,317
13.6%
Certificate
18,034
40.7%
879,529
30.9%
Level of education
inadequately described
1,498
3.4%
88,674
3.1%
Level of education not
10,078
22.7%
632,324
22.2%
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Study area total
Qualification
New South Wales
%
%
stated
Total
44,351
100.0%
2,847,294
100.0%
Source: Australian Bureau of Statistics (2007)
5.5
Income
The Central Tablelands study area has a slightly higher proportion of people in lower income brackets,
relative to the NSW average (Figure 5-4). Median individual weekly incomes have grown by around 20%
between 2001 and 2006, which is slightly higher than the state average.
$2,000 or more
$1,600-$1,999
$1,300-$1,599
$1,000-$1,299
$800-$999
$600-$799
NSW
$400-$599
Study area
$250-$399
$150-$249
$1-$149
Negative/Nil income
Individual income not stated
0%
5%
10%
15%
20%
25%
Proportion of Working Population
Source: Australian Bureau of Statistics (2007)
Figure 5-4 Gross individual weekly income (2006)
5.6
Summary
The implications for plantation forestry fire risk are:
The study area has a relatively large population and is experiencing minor growth. In addition, the
median age of the Bathurst and Orange LGAs (which account for two-thirds of the population) is
below the NSW average. This suggests that the area has sufficient fire-fighting capacity in the event
of a plantation fire. The other LGAs, however, have a substantially older population and are therefore
more likely to rely on Bathurst and Orange resources for fire control. Whilst the overall level of fire
fighting resources may remain the same, reductions in specific rural localities is likely to lead to a
reduction in initial attack capability in these localities;
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‘Tree-change’ populations establishing in the area may not have as significant appreciation or
experience of bushfire management, including the importance of fuel maintenance on properties, fire
reporting and an acceptance of prescribed burning operations; and
Agriculture, forestry and wood product manufacturing employ a reasonable proportion of the
population. These people have an additional incentive (over and above the wider population) to
ensure that fire risk is managed, as their income relies on the ongoing productivity of the land. This
influence may diminish over time, however, if the agriculture and forestry sector continues to
experience negative employment growth.
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6.
Study Area Fire Risk Aspects
6.1
Risk Factors
This section identifies the key fire risk factors for plantations specific to the Central Tablelands study
area, from those identified at a national scale (Section 1.6).
6.1.1
Sensitivity to fire
Plantations of the study area generally occur within areas of native forest or woodland vegetation or
adjacent to pasture and rural landuse. Proximity to rural and residential settlements may increase the risk
of bushfire ignition (Section 6.1.6).
The plantations of the study area are predominantly Pinus radiata, a species sensitive to fire (Section
1.6.1).
6.1.2
Plantation fuels and fire characteristics
P. radiata plantation fuels vary with stand age with grass fuels (first rotation) and potentially residual
slash fuels the major fuel type in a young plantation, with increasing fuels a result of silvicultural
treatments and duff layer as the plantation matures, though reduced grass fuels as the crown cover
establishes (Section 1.6.2). The level of grass fuels in and around plantations will vary with seasonal
conditions, with good spring rains that stimulate growth, followed by drier period that cures grasslands,
elevating the fire risk the most significantly.
Whilst bushfire is a regular feature of the plantation forests and surrounding landscape of the study area,
and a large number of fires can occur in unfavourable years, large scale plantation loss as a result of
bushfire is uncommon. Considerable expenditure on bushfire preparedness, mitigation and rapid initial
attack has historically maintained fire outbreaks at a small size. Significant plantation fires have occurred
irregularly, and are most likely in the drier western parts of the study area (Table 6-1). The 1982
Glenwood fire occurred in a drought affected fire season, and the 1985 Canobolas fire occurred following
heavy winter and spring rains the season before (resulting in prolific grass growth) followed by an
extremely dry summer (November to January).
Table 6-1
Significant plantation fires within the study area
Year
Size (hectares)
Species
1982
1667
Pinus radiata
Glenwood State forest (near Orange)
1985
2,439
Pinus radiata
Canobolas State forest (near Orange).
2006 (Dec)
721
Pinus radiata
Mt David, south of Oberon
2009 (Nov)
80
Pinus radiata
Mount Canobolas
2009 (Dec)
88
Pinus radiata
Macquarie Woods (east of Orange).
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Location
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6.1.3
Landscape vegetation cover and condition
Landscape fuel types vary across the study area and correspond to vegetation type, which is linked to
climate. Fuel types within Pinus radiata plantations are primarily duff and grass fuels, with native
vegetation occurring as strips associated with drainage lines (wet and dry sclerophyll forests, and dry
sclerophyll woodlands).
The following fuel types occur within and surrounding plantations of the study area:
Grassland - Land dominated by perennial grasses and broad leaved herbs with a lack of woody
plants – availability will vary with curing and management (ungrazed (near continuous fuel),
grazed/slashed (patchy fuel) eaten out: (sparse and discontinuous));
Woodland (grassy) - An overstorey dominated by an open to sparse layer of eucalypts with
crowns rarely touching, and typically 15 – 35 m high. Understorey cover has grassland
characteristics. Fuels predominantly surface fuel (with taller ungrazed grass extending into the
near-surface fuel layer) being dominated by grasses and with some litter fuels also present under
trees;
Dry sclerophyll forest (grassy understorey) - Timbered land dominated by eucalypts with
crowns rarely touching, and typically 15 – 35m tall. Understorey is dominated by long-lived
perennial grasses and herbs;
Dry sclerophyll forest (shrubby understorey) - Timbered land dominated by eucalypts with
crowns rarely touching, and typically 15 – 35m tall. Understorey is dominated by shrubs with a
typically sparse ground cover of mainly hard leaved sedges. Fuels dominated by surface and nearsurface fuel being a combination of litter fuels (surface) and shrubs with suspended litter (near
surface fuels). Some grassy components may also be present; and
Wet sclerophyll forest - eucalypt dominated forest with a tall (>30m) open canopy, generally
occurring in the east of the study area. The forest floor typically is covered with grasses and herbs,
with sparse shrub presence. Fuels are dominated by surface fuel; being a combination of grass
and litter fuels. Grassy fuel components recover quickly after fire. In long-unburnt areas, grass
fuels can extend from the surface into the near-surface fuel layer, which in some cases may be
added to by an increase in shrub components as time since fire increases. Bark fuels of rough and
smooth barked eucalypts can be significant in long-unburnt areas.
Within plantations grazing can be used to manage grass fuels, however the availability of stock and the
availability of other alternatives available to grazing lessees can limit effectiveness as a fuel reduction
technique.
Plantation slash and debris following harvesting and prior to site preparation may represent a significant
risk, as once ignited fine fuels may ignite heavier fuels making control difficult.
Potential increased spread of blackberries within plantations may result in increased fuels, and fire
behaviour characteristics, such as their contribution to rate of spread and intensity are not well known.
Blackberry infestations have the potential to limit fire fighter access to plantations.
Prescribed burning in natural areas adjacent to plantations or at strategic locations in the landscape
provides a cost effective means to reduce overall fuel hazard and reduce the intensity and rate of spread
of fires moving across the landscape.
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6.1.4
Surrounding land use and management
The fuel landscape within the study area is largely made up of production from dryland agriculture
(grazing, cropping), natural vegetation or plantation forestry, with settlement extending from major towns
(Section 4.1).
Where continuous areas of natural vegetation adjoin plantation areas, such as in the south-west and
south-east of the study area, the risk of high intensity bushfires developing and making runs into
plantation areas is increased significantly. Those plantations adjoining larger areas of natural vegetation
to the north through to east, the direction from which fires may move under higher fire danger days, are
particularly susceptible. Within the study area plantations adjoining natural forests on the more
vulnerable northern and western boundaries occur on the Newnes Plateau north of Lithgow, at Sunny
Corner, east of Oberon around Hampton, and in parts of Canobolas and Mullions Range forests near
Orange.
Where agricultural areas adjoin plantations the greatest risk is from grass fires, when sufficient grass
fuels (including crops) are present and cured. The risk of grass fires is reduced as fuels are grazed and
crops harvested, reducing fuel quantity. A large proportion (60% of total landuse) of the fuel landscape
within the study area has been cleared for agriculture purposes such as cropping and some grazing, with
smaller areas established for viticulture, orchards and hobby farms.
Approximately 16% of landuse within the study area is conservation, located largely to the east of the
plantation estate in a large block. Within the remainder of the study area, natural areas of woodland and
forest occur as scattered blocks surrounded by agriculture. The intensity of fires moving from forested
and woodland areas into managed agricultural lands drops significantly and presents increased control
options. The ‘isolated’ occurrence of forest and woodland within the study area, surrounded by
agriculture, means that landscape scale forest and woodland fires that may impact on plantations are
uncommon.
Where climate change results in agricultural enterprises are becoming marginal, and agricultural
practices change from more intensive uses (such as cropping) to less intensive uses (such as rangeland
grazing) there is the potential for grass fuels to present an elevated fire risk in some seasons. This can
occur as a consequence of drought breaking rains creating prolific grass growth in a destocked
landscape, resulting in a greater abundance of grass fuels available for the fire season.
6.1.5
Climate and weather
An overview of climate trends and projections for the region is provided in Section 3.
The most significant fires are likely to occur in summer in Very High to Extreme fire days. These typically
occur when a ‘blocking high’ establishes in the Tasman Sea ahead of frontal movements, with low
humidity, and high temperatures and wind occurring ahead of the front. The annual number of Severe
fire danger days (Very High and greater) is forecast to increase in the Central West (CSIRO 2007b)
under climate change scenarios.
In drought years bushfire risks are increased both in length and severity, as fires are more likely to start,
spread more readily, and remain alight for extended periods than in an average or wet year.
In Australia there is a strong correlation between drought years and high consequence bushfire events.
Severe hydrological droughts, which can be characterised as extended periods (several years) of well
below average rainfall (e.g. 1939, 1968, 1982/3, 2003) have occurred approximately every 20-30 years.
During fire seasons occurring in severe drought years, the potential for large scale high intensity fires in
within the Central Tablelands is elevated.
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Droughts are predicted to become more frequent, more widespread, and more severe as climate change
impacts occur (Hennessy et al., 2008). Long-term rainfall records for the Central West of NSW indicate
that drought periods occur three times per decade. Under climate change scenarios drought is projected
to occur 2-5 times per decade by 2030 and 1-9 times per decade in 2070 (CSIRO 2007b)).Under midrange CO2 level rise scenarios, severe (hydrological) drought is forecast to occur one to two times in
twenty years (Hennessy et al., 2008) – a doubling of the frequency of conditions associated with severe
fire seasons.
The most significant plantation fires of the study area were associated with droughts or as a
consequence of drought. The 1982 fire, that burnt 1667 hectares of plantation in Glenwood State Forest
(near Orange), occurred in the severe 1982/3 drought affected fire season. The 1985 fire that burnt
through 2439 hectares of plantation on Mount Canobolas bushfire occurred when prolific grass
developed following significant winter and spring rains in 1984, in a landscape still destocked following
the earlier drought, and followed by an extremely dry summer (November to January).
6.1.6
Ignition issues
Within the study area the main sources of ignition are lightning and arson. Less common ignition sources
include accidental ignitions from agricultural or forestry activities or mechanical works, powerlines arcing
or contacting with vegetation, and escaped agricultural burns, prescribed burns or camp fires. The
climate change implications in relation to lightning occurrence are not certain at this stage.
Fire preparedness guidelines apply to plantation harvesting, haulage and site preparation, and
automatically specify preparedness levels and activity restrictions based on fire danger rating.
Fires are more likely to occur on a Saturday and Sunday than on the average weekday, with the
increases on these days corresponding to increases human cause (accidental or suspicious) on these
days (Bryant 2008).
Plantation fires have the potential to result in large financial losses and fire occurring in native forests and
woodlands can result in loss of life and property as well as presenting a risk of fire spread into
plantations.
6.1.7
Local fire suppression capacity issues
Detection
The study area includes a network of five primary fire observation towers (Sunny Corner, Shooters Hill,
Burraga, Pennsylvania and Mount Canobolas) managed by Forests NSW. These fire towers are
complimented by Forests NSW aircraft (fixed wing and helicopter) and ground crews within the study
area to enhance fire detection capability.
The location of plantations adjacent to highways or shire roads provides for informal detection. Informal
detection has increased significantly across rural areas as a consequence of improvements in the range
and availability of mobile phone services (Mathews et al. 2010). Whilst tower observers currently
outperform remote fire detection cameras (Mathews et al. 2010) this disparity may be improved in the
future with improvements in technology (cameras, software and complementary drones). This
improvement in technology may address any issues that may arise where declining rural populations
may limit the future availability of tower observers.
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Access
The study area is well serviced by a well maintained road and trail network, directly constructed to
service the plantation industry (including through local government mandatory contributions) as well as to
service residents and other agricultural and industrial enterprises.
Suppression resources
The study area has a well established fire response and suppression capability associated within the
Pinus radiata plantation estate managed by Forests NSW. Forests NSW is one of four fire authorities in
NSW, the others being the NSW Rural Fire Service, the NSW Fire Brigades and the NSW National Parks
and Wildlife Service. Within the study area it maintains a large number of permanent fire fighters within
its workforce, supplemented by seasonal fire fighters and silvicultural contractors engaged by Forests
NSW. Additional Forests NSW personnel and resources can also be brought in to support local crews
from outside the area. Suppression resources include large fire tankers (3000 - 4000L), smaller four
wheel drive fire units (~400L), heavy plant and aircraft. These resources are complimented by NSW
Rural Fire Service volunteer units, which play an increasingly important role in controlling fires within
plantation areas, as well as prescribed burning operations adjacent to plantation areas. The NSW
National Parks and Wildlife Service also maintains a fire response capacity in the region, primarily
related to reserves along the western extent of the Blue Mountains and Wollemi National Park (in the
east of the study area), however participation locally in plantation fires is less common.
6.2
Climate Change Impacts on Plantation Risk within the Study Area
The following is a preliminary identification of the climate change plantation risk factors for the study
area. This analysis has been undertaken as a desktop exercise only with the intent to validate this
analysis through local knowledge and experience at regional workshops. There are many uncertainties
involved including the extent of climate change, the physiological impact on plantations and the success
of mitigation actions implemented to reduce climate change risk. In addition there are a range of socioeconomic factors that will also improve or exaggerate this risk profile. A summary of these potential
impacts is identified on a national scale in Section 1.8 and summarised for the study area below (Table
6-2).
Table 6-2
Climate change impacts within the study area
Factor
Direction of
Change
Detail
Plantation fire sensitivity
Negligible
Pinus radiata, the dominant softwood plantation species, is at the more fire
sensitive end of the spectrum of softwood species used in Australia.
Whilst a slight reduction in private pine plantations may occur, this species is
likely to remain the dominant plantation species in the region.
The introduction of carbon plantings is likely to comprise fire sensitive hardwood
species.
Fire sensitivity in plantation species is a function of species traits and
adaptations and is primarily controlled by genetics. Climate change is unlikely to
cause genetic adaptation or modification and is therefore unlikely to result in an
increase in fire sensitivity.
Plantation fuel quantity and
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Marginal
Litter accumulation in pine plantations is particularly influenced by plantation
FICCRF Plantation Amplified Bushfire Risk Study
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Factor
Direction of
Change
Detail
arrangement
increase
likely
management procedures (eg thinning) and rotation length. Fine fuels within pine
plantations consist primarily of needles, bark and twigs, reaching an apparent
equilibrium between deposition and decomposition at around 20 t/ha.
Projected precipitation and temperature is scenario dependant (CSIRO and
BoM 2007). Different influences on fuels may act in different directions
(negatively and positively). Increasing temperature in combination with CO 2
fertilisation has the potential to lengthen the growing season and increase water
use efficiency, increasing growth rates. Increased vegetation growth rates may
result in greater litter production and earlier build-up to fuel threshold levels
(Pinkard et al. 2010). However, decreased rainfall (especially where reductions
are significant) may limit or counteract the effects of CO 2, fertilisation and
lengthened growing season. Drier conditions may also affect litter
decomposition potentially resulting in more available fuels.
Native vegetation condition
Uncertain
Landuse is dominated by dryland agriculture and nature conservation. A
proportion of the fuel landscape within the study area is associated with native
forest and woodland, surrounding plantations and grasslands.
Climate change is not expected to impact the viability of grazing or native forest
and woodland landuses, however population growth expected in the region may
potentially lead to more subdivision of rural lands, fragmenting the fuel
landscape but increasing risk of both accidental and non-accidental ignitions.
Plantation management practices are expected to adapt to changing climatic
factors and the financial viability of forestry in the area is not expected to be
significantly impacted.
Native vegetation range and
distribution
Negligible
Climate change has resulted in decreased rainfall, increased temperature and
days over 35ºC. Projections to 2030 and 2070 (under all scenarios) indicate
increasing temperatures and pan evaporation, and decreased rainfall.
Gradual changes in the distribution of forest and woodland vegetation types
may occur, with trends towards dryer range formations (eg from forest toward
woodland structure) occurring under best case scenarios.
Native vegetation fire
regimes
Increased
risk
Fire regimes are impacted by a combination of land management practice and
climate influences. Grazing and fire suppression tend to reduce fire frequency in
woodlands and dry forest systems, in many cases promoting shrub
development (usually of less palatable fire prone pyrophytic species). Lower fire
frequencies (shift from more frequent low intensity fire to less frequent higher
intensity fire) tend to promote shrubbier understoreys. A drying climate, with
higher temperatures and more days over 35ºC, increased pan evaporation, in
combination with increased woodland/forest overstorey stress from competition
for water resources from an increasingly shrubby understorey, point to a likely
increase in fire frequency and intensity.
Landscape scale landcover
Negligible
Production from agriculture and forestry is projected to decline by 2030 over
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Factor
Direction of
Change
Detail
much of southern and eastern Australia due to increased drought and fire
(Hennessy et al. 2007) and change in the extent and distribution of plantation
and native forest and woodland may occur.
Rainfall variation in the study area may exacerbate the impact of drought.
Vegetation cover /land use
changes from socioeconomic or demographic
factors
Increased
risk
Native vegetation often occurs adjacent or in close proximity to rural and
residential land uses, particularly around the main growth centres of Bathurst,
Orange and Lithgow. Population is likely to increase, leading to increased
subdivision of rural land, combined with higher fire ignition risk associated with
increased human activity.
Increasing ‘sea change’ populations may have a lessened understanding or
awareness of fire risk.
Plantation owners take the threat of fire very seriously, and insure against this
eventuality. However, within the community and, to some extent within the
volunteer fire services, plantations are not regarded as higher value assets despite the employment they create and the long-term prospect of a significant
return to the regional economy.
Severe fire weather
Increased
risk
Projected precipitation and temperature is scenario dependant (CSIRO and
BoM 2007). Best estimates indicate increased temperature and decreased
rainfall, and combined with an increase in days over 35ºC may lead to
increased incidence of high to extreme fire days and extend the fire season.
Under worst case scenarios (runaway climate change scenarios), suggest
increases in temperature are accompanied by increased rainfall, and, combined
with increased humidity associated with higher levels of evaporation, all of
which may decrease the incidence of high to extreme fire days.
More severe drought
Increased
risk
Recurring drought is a feature of the study area, and current climate data for the
study region shows an overall decrease in rainfall. Drought intervals are
forecast to shorten increasing the likelihood of drought affected fire seasons.
Fire ignition
Increased
risk
Research on climate change implications for lightning occurrence across
Australia is inconclusive, however if an increased frequency of thunderstorms
were to occur in spring, natural ignition could increase.
As people are the leading cause of fires, climate change impacts on ignition
issues will principally be through any climate associated changes in
demographics. Fire ignition is often a result of non-accidental events, occurring
near built-up or recreational areas. Population growth is likely to increase,
resulting in higher fire ignition risk associated with increased human activity.
Suppression capability
21/19654/161549
Potentially
decreased
capacity
While worse case scenario projections may result in negligible increases in fuel
availability and extreme fire weather; higher temperatures and reduced rainfall
under best case scenario projections are likely to result in drier fuel. Combined
with an increase in the frequency of very high and extreme fire danger days,
FICCRF Plantation Amplified Bushfire Risk Study
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64
Factor
Direction of
Change
Detail
periods suitable for prescribed burning are likely to shift towards winter,
increasing the length and severity of the fire season and reducing the window
for prescribed burning.
Fire suppression is an ongoing priority for Forests NSW plantations and
firefighting capacity is likely to be maintained as part of the overall plantation
management strategy. Firefighting capacity within smaller, privately owned
plantations is maintained through local fire brigades and may be impacted by
recruitment and training of volunteers. This will be a significant issue where
declining populations in a locality impact on volunteer numbers and initial attack
capability.
Increasing extreme weather may also change the costs of fire prevention and
suppression (Pinkard et al. 2010).
Where declining rural populations limit the availability of volunteer fire fighting
resources, plantation owners and managers may have to engage additional
resources to maintain fire cover.
Fire detection
Negligible
A possible increased frequency in thunderstorms and consequent increased
ignition sources will require improved detection and maintenance of a strong
initial attack capacity.
Reductions in rural populations potentially reducing the availability of fire tower
observers may be offset by technology advances (remote cameras, aerial
drones) in the future.
Improvements in mobile phone coverage increase the likelihood of incidental
fire reporting.
6.3
Summary
The implications for plantation forestry fire risk are:
Pinus radiata is sensitive to fire, and at the mid stages of the rotation when plantations have sufficient
fuel to carry fire that will result in mortality or at the later stages where there is sufficient fuel for
higher intensity fires, increased measures are required to mitigate the fire risk in a climate where
higher fire danger days are more likely;
Changes in rainfall, temperature and evaporation may lead to both increased fuel yields and
increased fuel availability;
Rural population growth may increase the risk of accidental and non-accidental ignitions; and
Increased mitigation and suppression costs, through increased forecast fire frequency will need to be
addressed by forest owners while meeting commercial expectations.
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7.
Identifying Adaptation Options
The objective of the study is to identify the bushfire risks factors amplified by climate change, ‘calibrated’
locally through regional workshops. Bushfire risk factors are identified at a study area scale, and the
severity of each risk factor may vary across a study area, forest grouping, forest, compartment or subcompartment. Forest owners and managers can analyse and evaluate these risk factors in relation to
their own specific circumstances to determine if climate change may have an impact on on-going and
future management.
To efficiently mitigate the severity of each specific risk factor, the range of potential adaption options or
risk mitigation measures available can be analysed. The process to identify adaptation options or risk
control measures can be undertaken using the schematic approach below (Figure 7-1). This approach
can be applied at a range of scales, from a complimentary study and series of workshops to this present
study, through to an estate level analysis as part of strategic planning or business planning exercise. The
feasibility of successfully implementing a specific adaptation action may vary significantly between
organisation, owner and plantation.
It may not be possible to identify adaptation actions for all climate change bushfire risk factors, and
options identified require flexibility to account for the uncertainty in projections. Adaptation actions for
consideration may include enhancing fire detection and suppression capability, improving fire weather
forecasting and monitoring, using prescribed fire to reduce fuel levels (strategically and across the
landscape), developing a memorandum of understanding with adjoining landholders, adjusting
silvicultural practices to alter fuel array (thinning, rotation interval and pruning) and residue, and
infrastructure management (fire breaks, plantation design and access). Adaptation options for current
plantations are more restricted than those for future plantations, with some plantation vulnerabilities
carried through to clearfall. Establishment planning will need to account for each adaptation action and
balance this within commercial objectives.
For each action identify:
Bushfire risk factors
[study area level]
Identify and confirm
risks (or impacts) &
rank by priority
[management unit
level]
Identify
potential
adaptation
actions
• action leader (eg. individual; community; owner; business;
local, State or Federal Government);
• feasibility appraisal (comments regarding the level of
difficulty to implement based on cost/resourcing factors,
time constraints, technical complexity, local
practicality/social acceptability of the solution, level/types of
collaboration/partners required);
• indicative time to implement;
• dependencies on other actions or collaboration /
partnerships;
• benefits and risks of action implementation (social,
economic, environmental);
• risks associated with inaction;
• residual risks remaining after action; and
• knowledge gaps needing to be addressed
Figure 7-1 Identification of Adaptation Actions
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8.
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D.Adshead
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E Ray
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FICCRF Plantation Amplified Bushfire Risk Study
Central Tablelands NSW