A report from the ‘Climate change and the Victorian Alps – preparing for the fires of the future’ seminar, which was held as part of the speakers program for the 2022 Victorian backcountry festival at Mt Hotham on September 2.
Speakers included an academic, a local landcare representative, Parks Victoria and DELWP.
If you’re paying attention to what is happening in the mountains, it can be depressing. Some of the obvious impacts of climate change include more intense fires and longer fire seasons, which are leading to loss of snow gum woodlands and alpine ash, and dieback in the snow gums, which is caused by a beetle.
Snow Gums (Eucalyptus pauciflora) are the classic alpine tree of the Australian High Country, generally growing at heights between 1,300 and 1,800 metres asl. Anyone who has visited the Australian High Country will know – and probably love – these trees.
In recent decades, wildfire has been devastating huge areas of the Snow Gum forests, with significant fires in the Victorian High Country in 1998, 2002/3, 2006/7, 2013 and 2019/20. More than 90% of Snow Gum habitat has been burnt at least once in the last 20 years.
The species can survive fire. However, climate change driven fire seasons are leading to more frequent fire, which is causing more death of trees and changes to forest structure. In some instances, localised collapse of Snow Gum woodlands is now being observed. As climate scientist Michael Mann describes it, we are now seeing climate change play out in real time.
The same problem is occurring in the alpine ash communities, which grow lower on the mountains. These trees require at least 20 years between fires to be able to produce seed that can then replace the trees killed in fire. As fires become more frequent, we are seeing mass loss of these forests. The scale of the problem is so great that since 2013, the Victorian government has been running a seed gathering program that then reseeds burnt areas that are not otherwise able to recover.
In order to address some of these issues, Friends of the Earth and Upper Ovens Valley Landcare Group teamed up to host a forum called ‘Climate change and the Victorian Alps – preparing for the fires of the future’, which was held as part of the speakers program for the 2022 Victorian backcountry festival at Mt Hotham.
Dr Philip Zylstra, Adjunct Associate Professor, Curtin University.
Phil spoke about the impacts of fire on snow gums and alpine ash: what are the threats, and how we need to respond to more frequent fire. Phil’s work focuses on the drivers of fire behaviour and he has written widely about the impacts of fire on these vegetation communities. Snow gum communities are at risk as climate change drives a feedback loop of accelerating fire frequency and severity. As the mountains warm, fires become more frequent; but snow gum communities are twice as likely to burn in the decades after fire compared to older stands, so the landscape becomes more flammable at the same time as the climate gives it more fire.
A common tool used in land management to reduce fire intensity is fuel reduction fire (also called hazard reduction or prescribed burning), where controlled fire is put into the landscape to reduce the amount of woody material available when a natural fire burns through the area. This is a contested issue, with some proponents arguing for regular burning of forested areas to reduce fuel load and hence fire risk, and others, including many environmentalists and researchers, arguing that putting fire through an area ‘restarts’ the plant colonisation process that then results in more growth and a scrubby understory, which is actually more flammable than an unburnt older forest.
Phil argues that forests have a natural way of limiting fire via the ‘ecological controls’ of growth and succession. This describes the trend by which plants grow from close to the ground where they are available as fuel because flames can ignite them easily, to the height where they are difficult to ignite, and instead act as ‘overstorey shelter’ by slowing the wind acting on flames burning beneath them. As plants grow, they ‘self prune’ the lower branches as these are less useful due to shading, and this accelerates their progression into overstorey shelter. Taller plants have larger root systems, so that plants beneath them become limited for water, nutrients and light. As a result, understory species like shrubs become less common through ‘self-thinning’, and plant biomass in older forests is dominated by overstorey shelter (reducing fire risk), whereas more of the plant biomass in disturbed forests is close to the ground and available to be burned as fuel.
He notes that while a cool fire can be beneficial for many mountain forests and woodlands under certain conditions, this will trigger dense regrowth, which then increases the flammability of the forest for many years.
He asks how we can co-operate with Country to limit the flammability of forests. As noted in the graph above measured from Departmental fire records across Victoria, NSW and the ACT, the likelihood of severe fire increases in the years after a fuel reduction or natural fire. Although it goes down briefly after the fire, it gradually increases for years, often decades, depending on the type of vegetation. After a point, the forest is mature enough that it enters the less flammable phase in its life cycle. Phil has researched all of the dominant vegetation communities across the Alps – including lower elevation forests – and found the same pattern, with snow gums taking up to 20 years before fire risk goes down as the forest matures, and alpine ash taking slightly longer.
So how should we intervene?
Instead of doing fuel reduction burning at a landscape level, Phil recommends we limit this to much smaller areas close to homes and other human infrastructure. Intense fuel reduction burning in these zones has been shown to slightly reduce risk to human assets. We should leave the broader forested landscape of the mountains to grow older and hence move into a less flammable phase.
For this to happen, we need to reduce fire in the vegetation communities of the mountains. When wildfires do happen, Phil says we need to continue to focus on rapid ‘first strike’ suppression. If we are successful in this, this will lead to older, less flammable forests emerging, which will act as buffers to fires that do get started. In contrast, at present more regular fires are creating more flammable, fire prone landscapes because more of the ash, snow gum and other forests exist in an early regrowth phase of their life cycle.
Peter Jacobs, President, Upper Ovens Valley Landcare Group
Peter gave an overview about the changes occurring across the Victorian Alps. He says that the landscape is looking different because of climate change, which is making fires more frequent, with many negative impacts on biodiversity in the alps. As an example, the 2013 Harrietville fire burnt some areas of alpine ash for the third time in 10 years, depleting seed bearing trees and putting the forests at risk of collapse. The Victorian government subsequently undertook the first large scale post fire reseeding program in a national park to help alpine ash communities regenerate, which was again undertaken following the 2019/2020 fires.
Peter has lived in and around the Alps for a long time and says that the landscape has changed considerably since the 1970s. It is one single system, connected from the lowland rivers through the foothills and into the wet forests, then alpine ash into snow gums and finally the true alpine zones above the treeline. All of this land is being impacted by climate change.
Frequent fire used to be unusual in the Alps. Occasional, usually intense, fires would come through, but now it is a common visitor. To take the example of the Buffalo plateau, there were fires in 1926, then 1939, then a big gap until 1972. But from then there were 4 fires in around 35 years. Some areas, especially along the western flanks of the plateau, have been burnt up to four times, and the plateau as a whole has been transformed. What was older alpine ash forests and open snow gum woodlands, interspaced with open areas is now a mass of dead trees and thick regrowth.
A healthy fire interval in snow gum forests is about 50 years and in alpine ash it is about 80. These more frequent burns have pushed both vegetation communities towards localised collapse.
Peter noted that the Baw Baw plateau is especially important now in light of the scale of fires being experienced across the Alps. This is because it has been such a long time since the plateau has been burnt.
So how should we intervene?
We need to keep the ash seeding program going and ramp up the availability of seed. The alternative is to allow the burnt ash forests to transition to something else – most likely grasslands or montane forests.
We need to continue to actively protect peatlands from fire – identify key areas, and allocate firefighting resources to keep fire out.
The rivers that flow out of the Alps have all been impacted by fire. We need to continue to restore damaged river banks through erosion control, deal with invasive plant and animal species and in some instances maintain captive breeding programs for fire affected species.
Peter noted that there are many challenges to the resilience of the Alps, all of which must be dealt with. These include:
- Feral horses
- Logging of native forests outside the national park
- Feral deer
- Fire is a continual threat because of global heating (climate change)
- dieback of snow gums
Craig Hore, Ranger in Charge-Fire and Emergency Operations North East District, Parks Victoria.
Craig covered some of the issues around how climate change is impacting on the Alpine National Park and how land managers are responding.
There are a whole range of plans and strategies that guide how biodiversity is managed and protected in the Alpine national park, down to Project Plans which detail the year on year activities that occur within the park. Dealing with the threat of fire occurs at many levels, both in terms of preventative measures such as fuel reduction burning and response during fire events. The central document is the Greater Alpine National Park Management Plan, which was published in 2016.
Like Peter, Craig has seen the changes that have happened in the Alps in recent decades. Since the fires of 2002/3, the mountains have been transformed. With ever more frequent fire and drier conditions, he doesn’t feel that we can go back to what the Alps used to be like. In his early days as a Ranger he could drive through older forests for hours. But now so much of the park has been badly impacted by fires. “I doubt we will ever see those old forests again.”
So how should we intervene?
Craig noted that there are many threats to the integrity of the park and various programs that have been implemented to deal with them, including:
- Fire (protective measures include fuel reduction and strategic fuel breaks, Ash seeding in forests that have been burnt too frequently)
- Dieback (there is no landscape scale treatment for snow gum dieback as yet)
- Species such as the Mountain Pygmy Possum that require support or intervention (protective measures might include distribution of food to MPP populations, captive breeding programs, etc)
- Invasive animal and plant species (there are many programs underway intended to limit the populations of invasive species)
Aaron Kennedy, Deputy Chief Fire Officer and Director Forest Fire Operations, Hume Region, DELWP.
Aaron presented an overview of the significant impact of large scale fires on communities and the environment in north east Victoria during the past 20 years and the challenges confronting land and fire management agencies moving forward.
As other speakers outlined, Aaron pointed out the sheer number of fires that have occurred in the mountains in the last two decades – 2002/03 Alpine Fires, 2006/07 Great Divide Fires, 2009 Black Saturday Fires (which burnt significant areas of the Alps as well as the tragic impacts in places like Kinglake and Marysville) and of course the 2019/20 Black Summer Fires.
Over the past 20 years, approximately 4.1 million hectares of the 7.9 million hectares of public land in the state is not at reproductive maturity. This means that too frequent fire could threaten some flora species viability if they have not had sufficient time to produce seed before another fire event.
The 2019/20 Black Summer Fires also impacted young regrowth forests – for instance around 83,000 ha of alpine ash forest was burnt, of which about 17,800 ha was immature ash forest which burnt at high severity. Aaron pointed out that around 44,000 ha of immature alpine ash forest is at risk of conversion to ‘non forest’ from (ie removal of specific flora species i.e. Alpine and Mountain Ash replaced with other mid-storey species and shrubs) as a result of the 2019/20 season.
Like other speakers, Aaron pointed out the fact that climate change is making fire seasons longer – both here in Australia and overseas.
Climate change means:
- More severe fire weather
- More days over 35 degrees Celsius
- Less winter and spring rainfall and more frequent droughts
- Greater impacts on local communities
- Increased risk of community and firefighter fatalities
- Increased flammability of fuels
- Reduced access to national and international resources due to prolonged fire seasons. During the 2019/20 season, around 1,000 personnel came to Australia from North America to support our firefighting efforts. As seasons become longer in both hemispheres it will be hard to sustain this level of mutual support.
- Shorter intervals between fire, including severe fire
Climate change will also have greater biodiversity impacts:
- As fire risks increase, the risks to forests and biodiversity increases
- Increased risk to rivers and catchments threatens the fresh water ecosystem services, like water filtration, providing habitat
- Increased risk to endangered fauna species and communities
- Increased risk of burning older forests (endangered spp. habitat). More bushfires in older forests will put more forest below their Tolerable Fire Interval (TFI) and put it at more risk of irreversible damage
- Some fauna need old growth vegetation that have habitat features, such as old logs, leaf litter and tree hollows, to live and reproduce. If the vegetation burns before habitat features are replaced, which can be up to 100 years, species can become locally extinct
- Increased risk of forests not reaching reproductive maturity (burning forests below TFI)
- Increased climate impacts as bushfires increase carbon in the atmosphere.
So how should we respond?
Rapid and aggressive first attack on fires when they are small is essential. Many fires in the Alps start due to lightning strikes, often in remote areas and Forest Fire Management Victoria (FFMVic) has rappel and remote fire-fighting teams responsible for tackling these ignitions. Keeping fires small and containing fires quickly is good for the environment, communities, fire fighter safety and the tax payer.
As we look to the future we need a range of tools and resources to respond to fires and also prepare the community for any potential ignitions. There are a range of approaches being employed which include:
- Empowering local communities through the development of Community based Bushfire Management Plans and Living with Fire Strategy’s.
- Supporting ecosystem resilience, including protecting habitat structure and species diversity; introducing a mosaic of forest age class structure; and protecting fire sensitive communities during fire.
- Working with Traditional Owner groups to reintroduce Cultural Burning burning practices.
- Working with industry, research partners and land managers to ensure best practice and have an evidence based approach in decision making.
- Enhancing capability and capacity to fight fires in remote areas. This includes securing water supplies in remote areas for firefighting to reduce flight turn-around times for water bombing aircraft and remote firefighting crews.
Friends of the Earth has been tracking the loss of trees due to repeat fire – details here.
There is also a project to track and log dieback of snow gums caused by beetles. Details here.
There is additional information on Friends of the Earth’s proposals around fire available here.
A remote volunteer firefighting team
At the session, Cam Walker from Friends of the Earth (FoE) pointed out that in bad fire seasons we don’t have enough remote area firefighting capacity to stop all ignitions from lightning strikes. FoE suggests that Victoria establish a volunteer remote area firefighting team, trained in dry firefighting and able to be deployed to support FFMV firefighters.
The NSW, ACT and Tasmania has such volunteer teams.
You can find out more about the proposal here and show your support for the proposal.
You can indicate your interest in this program here (details will be used to aid our lobby efforts to see a volunteer established by demonstrating that there is interest in the community).
Acting on the recommendations of the Icon at Risk report.
You can sign a letter to the Victorian environment minister here, urging her to act on the recommendations in the Icon at Risk report.