New South Wales’ Forestry Corporation will this week start “selective timber harvesting” from two state forests ravaged by bushfire on the state’s south coast.
The state-owned company says the operations will be “strictly managed” and produce timber for power poles, bridges, flooring and decking.
Similarly, the Victorian government’s logging company VicForests recently celebrated the removal of sawlogs from burnt forests in East Gippsland.
VicForests says it did not cut down the trees – they were cut or pushed over by the army, firefighters or road crews because they blocked the rood or were dangerous. The company said it simply removed the logs to put them “to good use”.
However the science on the impacts of post-fire logging is clear: it can significantly impair the recovery of burned ecosystems, badly affect wildlife and, for some animal species, prevent recovery.
We acknowledge that for safety reasons, some standing and fallen burnt trees must be removed after a fire. But wherever possible, they should remain in place.
Hollows in fire-damaged trees and logs provide critical habitat for animal species trying to survive in, or recolonise, burned forests.
Indeed, the research shows post-fire logging is the most damaging form of logging. Logging large old trees after a fire may make the forests unsuitable habitat for many wildlife species for up to 200 years.
Long-term monitoring data from extensive field surveys shows hollow-dependent mammals, such as the vulnerable greater glider, generally do not survive in areas burned and then logged. Research by the lead author, soon to be published, shows populations are declining rapidly in landscapes dominated by wood production.
Forests logged after a fire have the lowest bird biodiversity relative to other forests, including those that burned at high severity (but which remain unlogged). Critical plants such as tree ferns are all but eradicated from forests that have been burned and then logged.
Fire badly disrupts forest ecosystems. Animals and plants then begin recovering, but most forests and the biota they support simply cannot deal with the second intense disturbance of logging so soon after a first one.
For example, young germinating plants are highly vulnerable to being flattened and destroyed by heavy logging machinery. And in an Australian context, post-fire logging makes no sense in the majority of eucalypt-dominated ecosystems where many tree species naturally resprout. This is an essential part of forest recovery.
Logs provide shade, moisture and shelter for plants, and rotting timber is food for insects – which in turn provide food for mammals and birds.
Living and dead trees are also important for fungi — a food source for many animals, including bandicoots and potoroos which have been heavily impacted by the fires.
Similarly on burnt private land, removing damaged and fallen trees will only hinder natural recovery by removing important animal habitat and disturbing the soil. If left, fallen trees will provide refuge for surviving wildlife and enable the natural recovery of forests.
While the sight of burnt timber can be disheartening, landholders should resist the urge to “clean up”.
Research in North America suggests debris such as tree heads, branches and other vegetation left by post-fire logging not only hinders forest regeneration, but can make forests more prone to fire.
And the economics of logging, particular after a fire, is dubious at best. Many native forest logging operations, such as in Victoria’s East Gippsland, are unprofitable, losing millions of taxpayer dollars annually.
Timber is predominantly sold cheaply for use as woodchips and paper pulp and fire-damaged timber is of particularly poor quality. Even before the fires, 87% of all native forest logged in Victoria was for woodchips and paper pulp.
Post-fire logging certainly has no place in national parks. But for the reasons we’ve outlined, it should be avoided even in state forests and on private land. Million hectares of vegetation in Australia was damaged or destroyed this fire season. The last thing our forests need is yet more disturbance.
VicForests response: VicForests told The Conversation that timber currently being removed by VicForests, at the direction of the Chief Fire Officer, is from hazardous trees that were cut or knocked over to enable the Princes Highway to be re-opened.
It said the timber would be used for fence restoration, firewood and to support local mills “protecting jobs, incomes and families. It would otherwise be left in piles on the side of the highway”.
“Any further post-fire recovery harvesting will occur in consultation with government including biodiversity specialists and the conservation regulator, following careful assessment and protection of high conservation values,” VicForests said.
The company said post-fire recovery harvesting, particularly of fire-killed trees, does not increase fire risk.
“Sensitive harvesting including the retention of habitat trees and active re-seeding is more likely to result in a successfully regenerated forest and a supportive environment for threatened species. This regenerating forest will have the same fire risk as natural regeneration following bushfire.”
Forestry Corporation of NSW response: Forestry Corporation of NSW said in a statement that small-scale selective timber harvesting operation will begin on the south coast this week.
The company’s senior planning manager Dean Kearney said the Environment Protection Authority, with the input of scientific experts “has provided Forestry Corporation with site-specific conditions for selective timber harvesting operations in designated parts of Mogo and South Brooman State Forests. These areas were previously set aside for timber production this year but have now been impacted by fire.”
“Strictly-managed selective timber harvesting will help prevent the loss of some high-quality timber damaged by fire, including material that will be in high demand for rebuilding, while ensuring the right protections are in place for key environmental values, particularly wildlife habitat, as these forests begin regenerating,” he said.
“The harvesting conditions augment the already strict rule set in place for forest operations and include requirements to leave all unburnt forest untouched and establish even more stringent conditions to protect water quality, hollow-bearing trees and wildlife habitat.”
David Lindenmayer, Professor, The Fenner School of Environment and Society, Australian National University and Doug Robinson, Honorary Visiting Fellow, Department of Ecology, Environment and Evolution, La Trobe University
Holly Kirk, RMIT University; Brendan Wintle, University of Melbourne; Casey Visintin, University of Melbourne; Freya Thomas, RMIT University; Georgia Garrard, RMIT University; Kirsten Parris, University of Melbourne; Kylie Soanes, University of Melbourne; Pia Lentini, University of Melbourne, and Sarah Bekessy, RMIT University
People living in cities far from the unprecedented bushfires this summer may feel they can do little more to help beyond donating to organisations that support affected wildlife. But this is not necessarily the case: ten of the 113 top-priority threatened animal species most affected by the fires have populations in and around Australian cities and towns. Conserving these populations is now even more critical for the survival of these species.
Here we provide various practical tips on things people can do in their own backyards and neighbourhoods to help some of the species hit hard by the fires.
Wildlife may arrive in your neighbourhood in search of resources lost to fire or drought in their ranges. Cities can become ecological traps, as they draw animals towards sub-optimal habitats or even death from threats such as cats and cars. But by providing the right resources, removing threats and connecting your backyard to surrounding habitat, you can turn your property into a refuge, not a trap.
The fires killed an estimated 1 billion animals and Australia’s threatened species list is likely to expand dramatically. As is often the case, the impacts on invertebrates have been largely ignored so far.
Despite the focus on animals, it is plants, making up 1,336 of the 1,790 species listed as threatened, that have been hit hardest. Early estimates are that the fires had severe impacts on 272 threatened plant species. Of these, 100 are thought to have had more than half of their remaining range burnt.
The impacts on individual plant species is profoundly saddening, but the impacts on whole ecosystems can be even more catastrophic. Repeated fires in quick succession in fire-sensitive ecosystems, such as alpine-ash forests, can lead to loss of the keystone tree species. These trees are unable to mature and set seed in less than 20 years.
Losing the dominant trees leads to radical changes that drive many other species to extinction in an extinction cascade. Other badly impacted ecosystems include relics of ancient rainforests, which might not survive the deadly combination of drought and fire.
It is difficult to know how best to “rescue” threatened plants, particularly when we know little about them. Seed banks and propagation of plants in home gardens can be a last resort for some species.
You can help by growing plants that are indigenous to your local area. Look for an indigenous nursery near you that can provide advice on their care. Advocate for mainstream nurseries, your council and schools to make indigenous plants available to buy and be grown in public areas.
Planting native species in your backyard is also the best way to provide food for visiting wildlife. Many species feed on flower nectar, or on the insects the vegetation attracts. Putting out dishes of fruit or bird feeders can be useful for some species, but the best way to provide extra food for all is by gardening.
Plants also provide shelter and nest sites, so think twice about removing vegetation, leaf litter and dead wood. Fire risk can be managed by selecting species that are fire-suppressing.
Urban gardens also provide water for many thirsty creatures. If you put out a container of water, place rocks and branches inside so small critters can escape if they fall in.
Backyard ponds can provide useful habitat for some frog species, particularly if you live near a stream or wetland. Please don’t add goldfish!
The best frog ponds have plants at the edges and emerging from the water, providing calling sites for males and shelter for all. Insecticides and herbicides harm frogs as well as insects and plants, so it’s best not to use these in your garden.
Piles of rocks in the garden form important shelters for lizards and small mammals.
It’s important to consider threats too. Cats kill native wildlife in huge numbers. Keep your pet inside or in a purpose-built “catio”.
When driving, think about killing your speed rather than wildlife – especially while populations are moving out of fire-affected areas in search of food. Slowing down can greatly reduce animal strikes.
With the loss of huge areas of forest, species like grey-headed flying foxes will need to supplement their diet with fruit from our backyards. Unfortunately, they risk being entangled in tree netting. If you have fruit trees, consider sharing with wildlife by removing nets, or using fine mesh bags to cover only select bunches or branches.
People have different levels of knowledge about our native wildlife, and some will be more affected by new wildlife visitors than others. Some of these critters are small and quiet. Others are more conspicuous and may even be considered a nuisance.
Try to discuss what you are seeing and experiencing with your neighbours. When you can, provide information that might ease their concerns, but also be sympathetic if noisy or smelly residents move in. It is important to tolerate and co-exist with wildlife, by acknowledging they might not conform to neighbourly conventions.
Given the unprecedented extent and intensity of these fires, it is difficult for scientists to predict how wildlife will respond and what might show up where. This is especially the case for species, like the regent honeyeater, that migrate in response to changing resources. New data will be invaluable in helping us understand and plan for future events like these.
If you do see an animal that seems unusual, you can report it through citizen-science schemes such as iNaturalist. If an animal is injured or in distress it’s best to contact a wildlife rescue organisation such as Wildlife Victoria or WIRES (NSW).
Our wildlife is under pressure now, but we can help many populations by ensuring safer cities for the species that share them with us.
Holly Kirk, Postdoctoral Fellow, Interdisciplinary Conservation Science Research Group (ICON Science), RMIT University; Brendan Wintle, Professor in Conservation Ecology, School of BioSciences, University of Melbourne; Casey Visintin, Postdoctoral Research Fellow, School of BioSciences, University of Melbourne; Freya Thomas, Research Fellow, Centre for Urban Research, RMIT University; Georgia Garrard, Senior Research Fellow, Interdisciplinary Conservation Science Research Group, RMIT University; Kirsten Parris, Professor of Urban Ecology, School of Ecosystem and Forest Sciences, University of Melbourne; Kylie Soanes, Postdoctoral Fellow, School of Ecosystem and Forest Sciences, University of Melbourne; Pia Lentini, Research Fellow, School of BioSciences, University of Melbourne, and Sarah Bekessy, Professor in Sustainability and Urban Planning, Leader, Interdisciplinary Conservation Science Research Group (ICON Science), RMIT University
Australians have helped raise millions of dollars to support Australia’s imperilled wildlife, such as to set up triage centres and evacuate threatened species like eastern bristlebirds and Macquarie perch.
But beyond the vital role of providing financial support, here are a few simple things individuals can do – and avoid – to help our native wildlife recover.
Photos of well-meaning people offering water from bottles to animals, especially thirsty koalas, often go viral online. But this is not a safe way to help koalas.
Animals must be allowed to drink water themselves, rather than us pouring water into their mouths. Animals, such as koalas, can’t drink quickly and poured water can fill their lungs, leading to potentially fatal aspiration pneumonia.
Still, providing safe, fresh drinking water is one crucial and practical way we can help them as summer grinds on.
This is particularly important since recent storms have washed ash, sediment and chemicals from burnt infrastructure into waterways, contaminating many catchments.
Water should be stationed at ground level, in a shaded location safe from predators, and in trees for birds and tree-dwelling species like possums, gliders and koalas. Check out DIY guides for building drinking fountains, or “watering pods”, for wildlife.
Sticks and rocks should be placed in the water to allow small species, such as reptiles, to climb out if they fall in. Water must be checked and changed regularly to ensure hygiene and avoid the spread of disease. And pets must be kept away from these locations (especially cats).
Authorities are searching the fire grounds for injured animals, and the public is reminded to avoid these areas until they’re confirmed as safe to enter.
But if you happen upon an injured survivor, what should you do?
First of all, call government agencies or trained wildlife rescuers, who can assist any injured wildlife.
Many animals may be in pain and frightened and some, including kangaroos, koalas and wombats, are potentially dangerous if approached. In urgent cases, such as when an animal is in obvious distress or has clear injuries, some animals can be carefully caught and wrapped in a towel, then placed in a well-ventilated, dark and secure box for quiet transport to wildlife veterinary hospitals for care.
Sadly, many animals are hit by cars during fires when they’re disoriented and panicked, and so it’s important to slow down in such areas.
You can also check animals found by roads for injuries and surviving young in pouches, and call authorities to assist. But always be careful of traffic when attending to animals on roadsides, and help other drivers be aware of you by putting hazard lights on and wearing bright clothes.
But feeding wildlife without expert advice and legal approval can do more harm than good.
Feeding inappropriate foods like processed foods, over-feeding, providing unhygienic foods or food stations, and attracting predators to food stations, can all be fatal for native wildlife.
Even some foods suggested online, such as bait balls (peanut butter mixes), can cause gastrointestinal issues for wildlife, potentially killing them. Similar issues can arise if wildlife are given some types of hay, vegetables, seeds, and fruits.
Supplementary feeding isn’t advised unless habitat and sources of food have been completely destroyed, and is only appropriate as a short-term emergency intervention until natural resources recover.
In some cases, fire may mean native animals are more prone to predators killing and eating them. And, depending on the habitat, it may take months or even years for plants and animals’ homes to recover sufficiently to provide safety once again.
However, new approaches – such as building artificial shelters out of fencing wire and shade cloth – may help to buy species time, keeping small mammals, reptiles and other potential prey safe from hungry mouths. This could occur both on private and public land.
Caring for wildlife after fires, whether they’re injured or have lost their homes, is a marathon, not a sprint. And given the scale of these fires, our wild neighbours need our increased support.
Some wildife species, such as bristlebirds, corroboree frogs, and mountain pygmy-possums, are being pushed to the brink of extinction and may need long-term captive breeding and release programs, or investment in active management of wild populations (such as the newly constructed feral predator-free area for Kangaroo Island dunnarts).
We can all help to make a difference and protect our remarkable and unique wildlife that so desperately needs our help.
Marissa Parrott, Reproductive Biologist, Wildlife Conservation & Science, Zoos Victoria, and Honorary Research Associate, BioSciences, University of Melbourne; Dale Nimmo, Associate professor/ARC DECRA fellow, Charles Sturt University, and Euan Ritchie, Associate Professor in Wildlife Ecology and Conservation, Centre for Integrative Ecology, School of Life & Environmental Sciences, Deakin University
When it comes to reducing the extent of bushfires, scientists disagree on the best way to do it. Hazard-reduction burning (also known as “prescribed burning” or “controlled burning”) is controversial and, depending on the scientific paper, it’s shown to either be effective or not work at all.
Hazard-reduction burning is the process of removing vegetation that would fuel a fire – the “hazard” – through burning, slashing or grazing. It’s one of the ways state governments try to prepare for looming bushfire seasons.
The Climate Council published a fact sheet in January this year titled “Setting the record straight on hazard reduction”. It concluded that, while important, in future “no amount of hazard reduction will protect human lives, animals and properties from catastrophic fires”.
So why are there conflicting views?
For its report, the Climate Council relied heavily on a 2015 study based on fire and weather records from southeastern Australia over a period of 34 years. This is a relatively short time when it comes to ecosystem cycles – the earth’s natural recycling process of resources like water and carbon.
The researchers of this study used a metric called “leverage” to evaluate the effect of hazard-reduction burning on reducing the extent of wildfires. “Leverage” in this context refers to the ratio between the area burnt by wildfires and the area burnt by prescribed burning.
And they concluded hazard-reduction burning has a statistically significant effect on the extent of wildfires, but only in forested areas with distinct annual drought periods.
The leverage measure implies that prescribed burning only increases the total area burnt, and is therefore ineffective in reducing fire extent.
Like all scientific papers, the conclusions of the 2015 paper are drawn from several assumptions. And while the conclusions are valid for the researchers’ focus, several assumptions don’t work in a land management context. For instance, it’s assumed only the extent of the area burnt is important, rather than the severity.
But the recovery of the plants, animals, nutrients and habitat after low-intensity fire is much quicker than after high-intensity wildfire, according to a long-term Victorian study.
Several other assumptions were also made in the 2015 study, and it is such assumptions that lead to conflicting conclusions with others. While this study is valid within the context in which it was undertaken and includes useful analysis, the conclusions the Climate Council draws from it aren’t supported.
A 2009 study looking at 52 years of fire history in southwest Western Australia identified the benefits of hazard-reduction burns. This includes it leading to fewer fires starting and a greater ability to suppress fires in prescribed burnt areas.
A big reason for the different findings is because, unlike the 2009 study, the 2015 study didn’t explicitly consider how past prescribed burns lower the severity of new high-intensity fires when they move in. This helps fire suppression efforts and helps reduce the spread of wildfires.
The 2009 study showed prescribed burning less than about 4% of a million hectares of forested landscape per year wasn’t enough to show trends in reducing wildfires.
But in the 2015 study the Climate Council used, only included 2% of prescribed burning in the forested landscape of southeast Australia, so a conclusion that prescribed burning was ineffective could have been expected.
In other words, not enough of the landscape was prescribed burnt to have a measureable effect, so it cannot be concluded that prescribed burning is ineffective at reducing the impact of bushfires from this analysis.
The Climate Council should have taken a broader view of the available scientific studies before drawing its conclusions.
There are many dimensions to the debate about whether to use hazard-reduction burns to mitigate and prepare for wildfires. And not all scientific studies will be equally relevant in addressing particular issues.
So before we decide whether hazard-reduction burning for land management is a good thing, we need to consider all of the variables. This includes increased ecosystem resilience, mitigation of wildfire number and extent, impact on human health, economic value, social impact, Traditional Owner culture, and more.
The Climate Council’s conclusions are drawn only from the consideration of reduced wildfire extent.
In debating the value or otherwise of prescribed burning, we need to use good scientific evidence, but our decisions must be based on the whole picture, not just a selective part of it.
On the night of January 9 2020, my wife and I secured our Kangaroo Island home and anxiously monitored the South Australian Country Fire Service (CFS) website for bushfire advice.
After many horrific weeks of bushfires, the winds had again shifted, and the fire front began a slow, nightmarish march eastward into the island’s central farmlands. Official warnings advised that the entire island was potentially under threat.
As my good neighbours and volunteer firefighters headed off to battle the flames elsewhere on the island, I desperately wanted to find a way to help. With no firefighting training, I felt I physically had little to offer. But I reasoned that my skills and training in remote sensing and spatial science could potentially turn satellite information into useful maps to track the fires, in more detail than those provided by the Country Fire Service and Geoscience Australia.
While I was ultimately successful, it wasn’t quite as straightforward as I thought. And what I learned about access to good-quality and up-to-date satellite bushfire information surprised me.
In principle, there are many good sources of free satellite imagery. But selecting, sourcing, understanding and processing a multilayered satellite image into an accurate burnt area map takes technical know-how that is beyond the reach of the people who need it the most.
We are fortunate to live in a time where satellite images are constantly uploaded to the web, often within hours of acquisition. There are many reputable sources for this information, including NASA Worldview, USGS Earth Explorer, USGS LandLook Viewer, and the Sentinel EO Browser.
These websites are gateways to the world of “big satellite data”, and I quickly found myself on a steep learning curve to efficiently navigate them and find recent imagery.
Once downloaded, the next hurdle I faced was how to process a data-rich satellite image into a meaningful and accurate map of the bushfire area. I scoured the internet for “how to” blogs, academic articles, spatial algorithms, and processing codes; these too are the products of much intellectual investment by global scientists, openly and freely available.
As a spatial scientist, I naturally found all this fascinating. But as a resident of an island under assault from bushfires, I also found it frustratingly time-consuming. I crashed my computer testing algorithms. I maxed out my hard drive. I spent hours on possibilities that turned out to be dead ends.
In the end, I produced burnt area maps from Sentinel and Landsat satellite images captured during the fires. I learned that this kind of information can indeed help firefighting and ecological recovery efforts, both during and after bushfires.
Initially I gave the maps to a group of farming friends who had been fighting fires around their properties for weeks. They told me the maps helped save time in assessing which areas had already burned, allowing them to focus on defending unburnt areas, and to make decisions on where to move livestock and install firebreaks.
The positive feedback inspired me to customise my processing techniques, so I could provide updates more quickly when new satellite images became available.
I embedded appropriate safety disclaimers into the maps and released them on Twitter and Spatial Points, a blog site managed by my research group at the University of Adelaide.
Within hours, I received messages that the maps were being used for ecological recovery efforts. The maps successfully highlighted remaining patches of habitat where endangered and vulnerable species had found refuge. Several government agencies even contacted me for burnt area information, which I’m told was used to assess infrastructure damage and habitat loss.
My experience shows there is a swag of free and regularly updated satellite imagery available, which when interpreted and presented appropriately can potentially be hugely helpful to firefighting and recovery efforts.
However, I am concerned that neither the general public nor decision-makers seem fully aware of the range of satellite information on offer. Nor is there a good understanding of the advanced technical skills needed to access and process imagery into useful map data.
This leads me to wonder whether I have stumbled upon a glaring knowledge gap in Australia’s bushfire preparedness.
How can we overcome this technological and information bottleneck? I don’t propose to have all the answers, but I do believe it would be sensible for governments, industry and research agencies to invest in the kind of capabilities that I developed while trying to protect my own local community.
As Australia faces a future of more frequent and extreme bushfires, there will doubtless be many people who would be glad of this kind of information when they need it most.
As bushfires in New South Wales are finally contained, attention is turning to nature’s recovery. Green shoots are sprouting and animals are returning. But we must accept that in some cases, the bush may never return to its former state.
We’ve all read the devastating figures of destruction this fire season. More than 11 million hectares of land burned across the country over a period of about six months. There is some evidence more than one billion animals perished.
While Australia’s environment has evolved to adapt to fire, our research shows we can no longer assume it will recover completely.
We are scientists and social science researchers who work in transdisciplinary climate change projects, liaising with park rangers, farmers, policymakers, emergency services and local government.
Our work involves scoping future challenges in land management and developing a range of plausible future climate scenarios for south-east Australia.
Our experience told us something like this catastrophic climatic event was possible, but as researchers we weren’t prepared to see such an inferno this summer.
Although fires are natural in Australia, they’re now occurring at an unprecedented frequency and intensity in areas that, historically, did not burn. This new regime does not allow the effective recovery of natural systems to their pre-fire state.
Fires in alpine ash forests (Eucalyptus delegatensis) are a good example of this.
Unlike many eucalypt species which can re-sprout after fire, this species’ only means of recovery is through germination via a seed bank in the canopy, and rapid germination and growth of seedlings after fire.
Multiple fires in quick succession kill seedlings before they reach maturity, disrupting the tree’s reproductive cycle and leading to local extinction of the species in the landscape.
Alpine ash forests have endured repeated fires in recent years. In 2013, a blaze in Victoria burnt more than 31,000 hectares of the Alpine National Park.
Vast areas have been burnt again in this season’s fires in the same places. Research reveals climate change is increasing the frequency and intensity of fires in the Australian Alps.
This ecosystem will not recover. It will instead transition into a new, different ecosystem, and many species which evolved to live in the original habitat, such as the alpine ash, will no longer be supported. They will be replaced by other vegetation types, such as other eucalyptus woodland, shrubland or grassland.
To further illustrate this point, take the Tasmanian pencil pine Athrotaxis cupressoides.
This slow-growing conifer native to Tasmania can live for up to 1,000 years. They are found in Tasmania’s highlands and sub-alpine regions – historically a Tolkien-esque landscape of moss and emerald green cushion plants, studded with thousands of tiny mountain lakes, called tarns.
But large fires across Tasmania’s pencil pine habitat in recent years, including those in 2016, reduced hundreds of isolated pencil pine communities to blackened skeletons. The stands of trees that remain are struggling to survive in a drying and warming climate.
All this is occurring in areas that historically did not experience fire, which allowed a suite of ancient, fire-sensitive species to persist.
As climate change worsens, the pencil pine will be restricted to even smaller areas. Higher temperatures and increased fuel loads increase the likelihood of destruction by fire. Areas where pencil pines have historically been protected will diminish in number and size.
In these cases and many others, animal species relying on these trees and their ecosystems are profoundly affected.
Well before the latest fires, Australia had an abysmal record on vertebrate extinctions. This summer’s fires have brought some animal species, including the Kangaroo Island dunnart, closer to extinction.
Future fire seasons will not be normal events, or even some kind of stable “new normal”, to which humans and nature will readily adapt. We’re seeing a trajectory of change in which our climate will shift faster than most living things can tolerate.
The Australian environment evolved with fire and in past conditions, could recover from fire. However climate change has altered the rules irrevocably.
We can no longer rest assured that nature will bounce back, and that knowledge should be a wake-up call for the world.
Grant Williamson, Research Fellow in Environmental Science, University of Tasmania; Gabi Mocatta, Research Fellow in Climate Change Communication, University of Tasmania; Rebecca Harris, Climate Research Fellow, University of Tasmania, and Tomas Remenyi, Climate Research Fellow, Climate Futures Programme, University of Tasmania
But it is heartening to remember that bushfire can be a boon to some plants and animals. We’re already seeing fresh green shoots as plants and trees resprout. Beetles and other insects are making short work of animal carcasses; they will soon be followed by the birds which feed on them.
Australia’s worsening fire regimes are challenging even these tolerant species. But let’s take a look at exactly how life is returning to our forests now, and what to expect in coming months.
Of course, bushfires kill innumerous trees – but many do survive. Most of us are familiar with the image of bright green sprouts shooting from the trunks and branches of trees such as eucalypts. But how do they revive so quickly?
The secret is a protected “bud bank” which lies behind thick bark, protected from the flames. These “epicormic” buds produce leaves, which enables the tree to photosynthesise – create sugar from the sun so the tree can survive.
Under normal conditions, hormones from shoots higher in the tree suppress these buds. But when the tree loses canopy leaves due to fire, drought or insect attack, the hormone levels drop, allowing the buds to sprout.
This summer’s fires left in their wake a mass of decaying animal carcasses, logs and tree trunks. While such a loss can be devastating for many species – particularly those that were already vulnerable – many insects thrive in these conditions.
For example, flies lay eggs in the animal carcasses; when the maggots hatch, the rotting flesh provides an ample food source. This process helps break down the animal’s body – reducing bacteria, disease and bad smells. Flies are important decomposers and their increased numbers also provide food for birds, reptiles and other species.
Once insects start to move back into an area from forested areas nearby, the birds that eat them will follow.
A CSIRO study after bushfires in Victoria’s East Gippsland in 1983 found several native bird species – flame and scarlet robins, the buff-rumped thornbill and superb fairy-wren – increased quickly to levels greater than before fire. As shrubs in the understorey regrow, other species will move in, slowly increasing biodiversity.
Since the recent bushfire in woodland near Moonbi in New South Wales, numerous bird species have returned. On a visit over this past weekend, I observed currawongs landing in the canopy, saw fairy wrens darting in and out of foliage sprouting from the ground, and heard peep wrens in tufts of foliage on bark and high branches.
Honeyeaters moved between burnt and intact trees on the edge of the blackened forest and butterflies visited new plants flowering after recent rain.
Weeds usually benefit when fire opens up the tree canopy and lets in light. While this has a downside – preventing native plants from regenerating – weeds can also provide cover for native animal species.
A study I co-authored in 2018 found highly invasive Lantana camara provided habitat for small mammals such as the brown rat in some forests. Mammal numbers in areas where lantana was present were greater than where it was absent.
Generalist species – those that thrive in a variety of environments – can adapt to burnt forest. But specialist species need particular features of an ecosystem to survive, and are far less resilient.
It requires large fires to create a specific habitat: big dead trees provide hollows for shelter and nesting, and insects feeding on burnt wood and carcasses provide a food source.
But for the Leadbeater’s possum to benefit from the fire regime, bushfires should be infrequent – perhaps every 75 years – allowing time for the forest to grow back. If fires are too frequent, larger trees will not have time to establish and hollows will not be created, causing the species’ numbers to decline.
Similarly in NSW, at least 50% and up to 80% of the habitat of threatened species such as the vulnerable rufous scrub-bird was burnt in the recent fires, an environmental department analysis found.
Only time will tell whether biodiversity in these areas is forever damaged, or will return to its former state.
Large fires may benefit some native species but they also provide food and shelter for predatory species, such as feral cats and foxes. The newly open forest leaves many native mammals exposed, changing the foodweb, or feeding relationships, in an ecosystem.
This means we may see a change in the types of birds, reptiles and mammals found in forests after the fires. And if these areas don’t eventually return to their pre-fire state, these environments may be changed forever – and extinctions will be imminent.
Australia’s recent bushfires have razed over ten million hectares, and killed at least a billion animals. It’s likely countless more will die in the aftermath, as many species face starvation as the landscape slowly regenerates.
Even before the bushfires hit, we were working on supplementary food to help recover the critically endangered mountain pygmy-possum. They are seriously threatened by climate change, historic habitat destruction and more frequent intense fires.
Just months ago we landed on a recipe for Bogong Bikkies, nutritionally suitable baked biscuits that have the consistency of an ANZAC biscuit, taste a bit like a nutty gym protein bar and smell a little like Cheds crackers.
We never imagined our work would be needed so quickly – or urgently – but now our Bogong Bikkies are being deployed across the boulder fields of NSW, providing vital supplementary food to native species such as pygmy-possums, native bush rats and dusky antechinus.
Mountain pygmy-possums are the only Australian marsupial that hibernate every winter under snow, making it essential they build fat reserves before their long winter sleep. The main food source during their spring/summer breeding season is the migratory bogong moth.
However in 2017 and 2018 the billions of expected bogong moths largely failed to arrive, leaving many females underweight and unable to produce enough milk for their young. Due to a lack of food, 50-95% of females in monitored Victorian locations lost their entire litters.
In response, Zoos Victoria’s Healesville Sanctuary proposed creating a new supplementary food that could be used in the wild to support possums and their young until moth numbers recover.
Ten years ago, we analysed bogong moths to determine the fats, proteins, carbohydrates, vitamins and minerals required for a suitable breeding diet for possums in our captive breeding program.
While we have a successful diet for the possums in our care that includes nuts, insects, vegetables and a specially developed “bogong moth substitute”, the blend has the consistency of a soft caramel (or bogong moth abdomen) – not suitable for feeding in the wild. We needed a shelf-stable, long-lasting, nutritionally suitable food that could feed remote wild populations.
Throughout 2019, using our existing analyses of bogong moths, we worked with world experts in veterinary nutrition to develop Bogong Bikkies – nutritionally suitable baked biscuits for mountain pygmy-possums, and other species that live alongside them. We collaborated with Australian wildlife diet experts, Wombaroo, to have our new product commercially developed.
We then trialled the bikkies with the possums in our care at Healesville Sanctuary, so we could monitor whether the food was palatable or caused any health issues. It was a huge success. The possums liked the food, but happily ate other food too. This was exactly what we wanted: something that was completely safe and would be readily accepted, but not chosen over natural food sources.
Once satisfied our captive trials were a success, we had to find the best way to deliver food safely to possums in boulder fields in the wild. This meant buying or making 12 different feeder prototypes. Our local hardware store knew us all by name! We tested four feeders, most of which were designed and built on-site, and chose the most successful three for trials in the wild.
Working with Parks Victoria and the Victorian Mountain Pygmy-possum Recovery Team, we tested these three feeders at 20 stations deep in the Alpine National Park, monitored with remote infrared cameras.
Over the last few months, Zoos Victoria and Parks Victoria staff have been refilling feeders, changing camera batteries and analysing hundreds of thousands of images and videos. After months of work, watching wild mountain pygmy-possums, native bush rats and dusky antechinus visiting our feeders and eating the food was a triumph.
Halfway through our research, some of the worst bushfires ever seen in Australia left habitats destroyed and our precious wildlife dead or starving. Victoria mountain pygmy-possum populations have so far not been directly impacted by fires this season, but the populations of northern Kosciuszko National Park, New South Wales, were hard hit.
While the habitat was destroyed, we hoped some possums had survived deep in the boulder fields, as they have with previous fires. But surviving the initial fire is no help, if their environment and food sources have been so devastated that they can’t gain enough weight to hibernate before winter’s snow.
Within days of the January fires, we had packaged up our most successful feeder type, examples of our cooked bikkies, our best recipe and 30kg of Bogong Bikkie mix, and rushed it urgently to our NSW partners.
Teams from the NSW government’s Saving Our Species and NSW National Parks and Wildlife Service have now built and deployed 62 feeders and water stations in six boulder fields, baked batches of bikkies and started emergency feeding.
We’re thankful to have the food developed and research ready to assist. It is important to note, though, that such supplementary feeding is very intensive, and only appropriate for native species facing emergency situations, such as catastrophic fires.
If these bushfires teach us nothing else, it is the value of preparation, hard work and early funding to develop a range of conservation tools.
While we should all hope for the best, we must plan for the worst.
This article was co-authored Dr Kim Miller, Life Sciences Manager, Conservation and Research, at Healesville Sanctuary, Zoos Victoria, and Dr Leanne Wicker, Senior Veterinarian at Healesville Sanctuary, Zoos Victoria. The authors acknowledge Dr Linda Broome and the team from Biodiversity and Conservation (South East Branch) of the NSW Department of Planning, Industry and Environment for their work protecting the Mountain Pygmy-possum.
This article was corrected to clarify the impact on the mountain pymy-possum populations of northern Kosciuszko National Park.
Marissa Parrott, Reproductive Biologist, Wildlife Conservation & Science, Zoos Victoria, and Honorary Research Associate, BioSciences, University of Melbourne and Naomi Ezra Davis, Environmental Scientist – Fauna, Parks Victoria; Honorary Fellow, School of BioSciences, University of Melbourne