An assessment of non-climate, climate change, weather and drought factors that influence the extent, intensity and severity of major bushfires in forests across southern Australia

This article relates to the ongoing debate on ARR.News: Bushfires, Logging, Burns & Forest Management

John O’Donnell

The authors concern areas particularly relate to the large impacts of large and intense bushfires, community safety, fire fighter safety and establishment of safe, healthy and resilient landscapes.  There is a lot of community concern in regards to the extent and impacts of large bushfires across Australia and it is important that all the factors involved in the extent, intensity and severity of major bushfires across Australia are teased out. This article is focussed on forested areas across southern Australia. 

There has been a major focus on climate and climate change factors in regards to the extent, intensity and severity of major bushfires across Australia.  Putting climate, climate change, weather and drought factors aside for the moment, it is important to assess all the other factors that influence the extent, intensity and severity of major forest bushfires across Australia during past and recent history, and this has been undertaken in this article.  Some factors influence the extent of major forest bushfires across Australia, others influence intensity and severity and some factors influence extent, intensity and severity of major bushfires.

This assessment is an important step in order to:

• identify factors that aren’t or haven’t been adequately considered or missed in relation to non-climate, climate change, weather and drought, that influence the extent, intensity and severity of major forest bushfires across southern Australia;
• integrate the information in relation to this matter, assessing this area in detail, particularly in relation to southern Australia;
• identify action and opportunity areas;
• assist in reducing the extent, intensity and severity of major bushfires major bushfires across southern Australia; and
• consider implementation of the identified factors into fire management systems

This article isn’t a criticism of political processes nor fire authorities nor management. It is simply an examination of the non-climate, climate change, weather and drought factors/ potential factors that influence the extent, intensity and severity of major bushfires across Australia, an important step in managing bushfire systems and in the actioning of opportunity areas.

Non-climate, climate change, weather and drought factors/ potential factors that influence the extent, intensity and severity of major bushfires across southern Australia are arranged into factor headings and outlined below.  Each factor may not necessarily apply in each state, region or area or has varied over time, however it is important to tease the factors out.

The factors include:

Factors in relation to prescribed/ cultural burning and fuel management across landscapes, including:

1. Inadequate low intensity prescribed burning programs across forested landscapes, often of the order of 1 % (in some cases up to 2 %) of forested area per year, except for WA, where considerably higher areas are achieved (up to 8 %) and wildfire areas reduced.  Inadequate prescribed burning programs not breaking the connectedness of fuels >6 years old increases the risks of large-scale bushfires.  Prescribed burning is used here as it is common terminology, other terminology includes hazard reduction burning, controlled burning or ecological maintenance burning (EMB).  The latter term normally fits the bill as low intensity burning is important to maintain forest health and safe environments.
2. Inadequate Aboriginal cultural burning programs, including across landscapes.
3. Focus on prescribed burning near assets/ towns, with an inadequate landscape focus, increasing landscape fire risks to communities in difficult fire conditions.
4. Restriction of prescribed/ cultural burning in wilderness areas in many cases. These are often large areas.
5. Extensive barriers and rules restricting the undertaking of prescribed and cultural burning at state and federal level.
6. Focus on protection individual threatened species rules that restrict sensible landscape . prescribed and cultural burning programs, that would otherwise help protect these same individual species from high intensity bushfires.
7. Focus on  very long fire intervals, restricting sensible landscape prescribed and cultural burning programs and putting at risk extensive flora and fauna species and areas from intense and severe bushfires. 
8. Restriction of prescribed burning programs even further following major bushfire events.
9. Slow and cumbersome prescribed burning application process for many landholders.
10. Shorter seasonal timeframes for prescribed burning in some locations.
11. Prescribed burning can at times go wrong, although in safer periods than bushfires.
12. Inadequate fuel management programs in many areas using techniques such as mechanical fuel treatments and grazing.
13. Inadequate focus on the important issue of avoiding/ restricting the extent and impacts of intense bushfires, there needs to be a greater focus on bushfire intensity/ severity that is damaging ecosystems, including flora, fauna, waterways and heritage impacts.

Factors in relation to awareness and actioning on native forest biomass/ ground and ladder fuel loads influencing bushfire risks, including:

1. Actual forest fuel loads/ ladders (surface, near surface, elevated and canopy fuels),  in many cases are high and dense, increasing bushfire risks and risks of crown fires, with forests often having dense understoreys of flammable woody shrubs that provide fuel for bushfires which can reach tree crowns. 
2. Changes in fuel loads since European settlement, these have increased in many areas.  As noted in Mariani et al. “We found grass and herb vegetation dominated the pre-colonial period, accounting for about half the vegetation across all sites. Trees and shrubs covered about 15% and 34% of the landscape, respectively. After British invasion, shrubbiness in forests and woodlands in southeast Australia increased by up to 48% (with an average increase of 12%)”.  Refer to information on the Victorian 1851 bushfires.
3. Changed tree/ plant biomass since Aboriginal burning practices were curtailed and many forests and woodlands that were open are now closed forests
4. Inadequate annual fuel loads/ ladder assessment. These fuels are not assessed and updated annually and information is not publicly available to communities to assess risks.
5. Inadequate consideration of dead fuel from intensive bushfires and massive regeneration following bushfires and rapid build-up of ground and ladder fuel loads and layers after intense bushfires.
6. Inadequate consideration and action in regards to addressing fire brand risks, including those associated with dense forests with high fuel loads.
7. Changed levels of grazing (particularly cattle) within forested areas than in the past, increasing bushfire risks. 
8. Changes in rabbit populations following the introduction of myxomatosis, rabbits in past reduced fuel loads, grass and regeneration in grassland and forests between the 1870s to the early 1950s, reducing bushfire risks in many cases at these times.  There was active tree, shrub and grass regrowth following the successful introduction of myxomatosis, including in the 1950s.
9. Changes in weeds, weed species and weed growth of a number of species across grassland and forested areas that can increase bushfire risks, extent and difficulty of control.  One example is blackberries increasing over time, it is pleasing to see a focus group relooking at this issue.
10. Variation in rainfall, heavy rainfall many months before bushfire seasons increases fuel levels.
11. Combination of the factors listed immediately above.

Factors in relation to the extent and distribution of forest vegetation types and forest issues, including:

1. Influence of extent and distribution of forested vegetation types across regional areas, states and the nation on bushfire extent and intensity.
2. Influence of vegetation height and fuel load on the likelihood and impact of crown bushfires and high severity of bushfire impacts.
3. Variation in flammability of species, as noted by Fletcher many less flammable species have disappeared, replaced by more flammable species since European settlement with the loss of cultural burning.

Factors in relation to establishment of safe, healthy and resilient landscapes and adaptive land management influencing bushfire risks, including:

1. Inadequate understanding at most levels of government of safe, healthy and resilient landscapes, including in regards to establishment and maintenance.
2. Failure to address the declining health of forests such as chronic eucalypt decline increasing fuel and fire risks as a result of inadequate use of mild fire across landscapes.
3. Failure of lock up and leave approach applying to many conservation areas, increasing bushfire risks.
4. Reduced forest harvesting/ access and bushfires following increased reservation to conservation estate and associated reduction in skilled forest workforces, skilled forest machinery operators and associated access.
5. Inadequate levels of low intensity burning and forest thinning, important in the setting up of resilient fire landscapes, as the USA have identified and are actioning.

Factors in relation to bushfires, bushfire management approaches and outcomes influencing bushfire risks, before and during bushfires, including:

1. Changed focus on bushfire suppression at the expense of adequate fire mitigation programs across landscapes, including very large expenditure on aircraft hire.  The provision of extensive ground fire tanker fleets is important but the value of large and very expensive aircraft fleets is of questionable value.
2. Overfocus on centralised bureaucracy and decision making, in some cases with provision of fire advice sourced from researchers, often focussed on unproven modelling and at the expense of listening to active and retired experienced land and fire managers.
3. Inadequate safe access and strategic fire breaks in many forested areas, especially noting high fuel loads in forests.
4. Mass of actively growing regrowth and a lot of dead fuels following major intense bushfires, increasing bushfire risks.
5. Variation over time in season in relation to time of fire season when bushfires start.
6. Variation in effectiveness of bushfire prevention activities.
7. Failure of bushfire inquiries to address the key issues of inadequate prescribed burning and high fuel loads across landscapes and to adequately listen to inquiry responses in regards to these issues.
8. Inadequate focus on the damaging issues of bushfire intensity and severity as a key issue undermining sustainable  forest and conservation management and increasing fire fighter risks, resulting from high fuel loads..
9. Inadequate and regular high level independent performance auditing of fire management by the Auditor Generals in some states, particularly in regards to bushfire mitigation or alternatively mitigation and suppression considered together.

Factors in regards to bushfire attack influencing bushfire risks, including:

1. Effective utilisation of some firefighting techniques are not used at times when they should be to contain bushfires more quickly.  This includes backburning not used when it should be at times and at times slow speed of initial attack, noting that at times resources can be stretched.
2. Variation in effectivess of bushfire mopping up.
3. Variation in involvement of local government areas in bushfire planning, bushfires, bushfire fighting and mitigation/ prescribed burning in many cases.
4. Inadequate action in regards to the fact that bushfire attack is more difficult and risky in heavy fuels.

Factors in relation to challenges of terrain, lightning and firefighting, including:

1. Difficult terrain factors influencing rate of spread, including faster spread uphill (slower downhill) and the influence of aspect and channelling of winds.
2. Difficult terrain which can hampen firefighting, especially where there is inadequate access and high fuel loads which can be dangerous for firefighters.
3. Variation in lightning storms over seasons, times and locations.  At times, fire fighters are overloaded undertaking bushfire attack against numerous lightning strikes in one area.

Factors in relation to fire and bushfire funding and cost issues influencing bushfire risks, including:

1. Inadequate funding of mitigation at the expense of suppression.  As noted by Deloitte Access Economics (2022): “Australia’s disaster relief strategies are underpinned by a cycle of underinvestment in resilience and adaptation. It’s been estimated by the Productivity Commission that 97 per cent of all-natural disaster funding in Australia is spent after an event, with just 3 per cent invested prior to an event to reduce the impact of future disasters.”
2. Inaction in regards to using mitigation to reduce suppression costs, especially where sound prescribed burning programs are undertaken across landscapes.
3. Variation across agency funding to undertake sound prescribed burning programs across landscapes, some government sectors/ agencies aren’t adequately funded for this.
4. Inadequate incentives are applied for undertaking prescribed burning on freehold and lease lands to provide sound prescribed burning programs are undertaken across landscapes and indeed better protect communities and state lands.

Factors in relation to learning from bushfires and history in order to optimise fire mitigation and bushfire attack influencing bushfire risks, including:

1. Missed learning opportunities in regards to completing reviews of major bushfires by experienced fire fighters/ foresters and inadequate sharing of these learning advices across Australia.
2. Missed bushfire learning opportunities, noting there have been very large bushfires in the past that highlight important fire and bushfire lessons that haven’t been captured and lessons taught to land managers and fire fighters.  The author has written about three of these, the 1851 Victorian bushfires over 5 million hectares, the 1952 Mangoplah fire in NSW and Victoria over 390,000 hectares and the 1974/ 75 bushfires in central Australia over 117 million hectares.  There are important learnings in all of these cases.
3. Missed bushfire learning opportunities, at times, the author is aware of cases where bushfires in locations where individual fire histories, broad fire history and particular bushfire risk areas hasn’t been identified nor applicable training provided.

Factors in relation to risk management, including:

1. Effectiveness of local bushfire risk management plans.  In many cases, local bushfire risk management plans aren’t effectively addressing bushfire risks and threats, refer impacts of 2019/ 20 bushfires on a range of towns and landscapes.
2. The focus on suppression and not mitigation across landscapes has serious risk management limitations, including the fact that sound mitigation programs of the order of 8% of forested area per year reduce bushfire areas.

Factors in relation to people, communities and preparedness influencing bushfire risks, including:

1. Increasing number of people living in regional and city locations, including the wildland urban interface, increasing risks of bushfires starting and impacts.
2. Changed focus of firefighters at times on protecting increasing houses and assets during bushfires.  This reduces opportunities to attack bushfires, noting the protection of life and property comes first.
3. Changes in human activities and behaviour, including burning off, trains, powerlines, campfires, fireworks and arson.
4. Inadequate bushfire design, layout, controls and mitigation in many towns and cities.
5. Inadequate ongoing focus in many towns and cities on bushfire protection and reducing bushfire risks.
6. Variation in levels of community participation and preparedness for bushfires over time and location.

Conclusions

It is readily apparent that there are a large number of non-climate, climate change, weather and drought factors that influence the extent, intensity and severity of major bushfires across Australia across the 11 heading issues.  Particular factors can vary across states, regions and fire seasons and can vary over time.  In some cases, these factors are interlinked, but separated into relevant heading categories to optimise consideration of this important issue. These factors can and do occur together in combinations, increasing bushfire risks, extent, intensity, severity and reducing potential of bushfire control options and effectiveness.  Many of these factors haven’t been and aren’t being adequately considered in relation to bushfire extent nor intensity, nor considered together.

All of the 11 heading issues involve a number of both “Human” and “Fuel” issues in relation bushfire extent and intensity (using the Human, Fuel and Climate triangle approach, with climate not assessed here).  The “Challenges of terrain, lightning and firefighting” heading involves another category that the author has added, a very important component of bushfires.

It is important that the above factors/ combination of factors that influence the extent, intensity and severity of major bushfires across Australia are considered in implementing sound fire management systems.  The factors provide a base allowing consideration of opportunity areas to progress this matter and explore ideas and innovation, including in relation to community safety, fire fighter safety, native fauna habitat safety, the establishment of safe, healthy and resilient landscapes and, importantly, reducing bushfire extent, intensity and severity.

Potential opportunity areas associated with the factor list include:

• Individual bushfire brigades, bushfire districts and bushfire regions, this could be completed in a sit down exercise, possibly over a meal;
• Using the above listed factors for researchers undertaking bushfire research;
• Assessment of the factors list subjectively against a range of times over the past, such as the 1950’s, 1980’s, 2000 and now to ascertain changes over time.

If we as a society don’t identify all the non-climate, climate change, weather and drought factors that influence the extent, intensity and severity of major bushfires across Australia and action associated opportunities, Australia will continue to have more of the same disastrous bushfires, impacting on communities, fire fighters, flora, fauna and the environment.

About John O’Donnell

John is a retired district forester and environmental manager for hydro-electric construction and road construction projects.   His main interests are mild maintenance burning of forests, trying to change the culture of massive fuel loads in our forests setting up large bushfires, establishing healthy and safe landscapes, fire fighter safety, as well as town and city bushfire safety.