On January 1 this year, the commercial logging of native forests ended in Victoria and Western Australia. It was one of the most significant changes in the history of forest management in Australia.
These practices are worth discussing. But conflating them with the destructive commercial logging practices of the past is unwarranted.
We have a rare opportunity to consider a fundamental question – how much should we intervene and manage our forests? With commercial logging gone, should we aim to create “wilderness” – nature without people – or should we manage Country, as Australia’s Traditional Custodians have done for millennia?
Forest Country has changed profoundly
Before European colonisation, Traditional Custodians managed Country through the careful application or exclusion of fire and watched which plants grew and which animals thrived. Over tens of thousands of years, this experience accumulated.
Unfortunately, in the past 250 years of colonisation, Australia’s forested landscapes, once tended for thousands of generations, have changed profoundly.
These changes began with the displacement of Traditional Custodians and the sudden change to cultural fire regimes. In Tasmania, for instance, Palawa people used fire to create open woodlands. After colonisation, their fire regime was abandoned and the woodlands reverted to rainforest.
More recently, large areas of Australia’s forests have been damaged by a century or more of logging, land clearance, bushfires and flooding. As a result, today’s forests would be unrecognisable to earlier generations of Traditional Custodians.
In response, some Traditional Custodian groups in Victoria have restarted cultural management, partnering with Western scientists to begin to heal Country.
If these efforts are successful, we expect to see more biodiversity, healthier, more resilient forests, as well as new support for Traditional Custodians’ management of cultural landscapes.
What does it mean to care for a forest?
To be clear, no two forests are alike. There’s no blueprint to manage all forests.
Some forests are fire-tolerant, while others are fire-sensitive. Each forest has its own history of disturbances and its own ability to respond to future disturbances.
Forest structure matters too. Forests comprised of large trees are more likely to stay healthy and recover quicker from bushfires than forests of densely packed small trees.
Caring for Forest Country means reading the needs of each forest to ensure it can endure whatever the future holds.
Removing trees to save the forest?
You might look at a forest with lots of small trees and think it’s a good thing – the forest is growing back.
But you can have too much of a good thing. Very dense forests typically emerge in response to an intense disturbance, whether logging, floods, or fire. Tens of thousands of seedlings can regenerate per hectare. As they grow, the seedlings compete intensely for water, light and soil nutrients.
At such high densities, growth quickly slows and the overall health of the forest declines. This delays the development of large trees, which are disproportionately important to bird, mammal and insect species.
Worse, because these young trees are growing slowly, they are vulnerable to bushfire for decades longer. This is crucially important, as climate change is triggering more frequent landscape-scale bushfires.
Thinning forests is done by removing some trees so those remaining can grow larger, faster. It’s similar to how gardeners thin out a vegetable patch, removing weaker seedlings so others can thrive.
Around the world, thinning has been done by foresters for centuries to speed up production of larger, more valuable logs. But thinning can benefit forests in other ways.
Thinning is not a silver bullet – it may produce ecological benefits in some forests, but not in others.
For instance, researchers explored whether past commercial thinning operations affected the amount of a tree’s crown consumed by subsequent bushfire. In mountain ash forest, thinning didn’t change the rate of crown consumption in either young or old forests. In drier forests, thinning reduced fire severity in young forests – but not in old forests.
This raises important questions: If the thinning had been done for ecological, not commercial, reasons, would the results have been different? If they had been done in other forest types, would the results have been different?
We don’t have good answers to these questions because so little research on ecological thinning has been done in Australia’s forests. But we do know that it has had positive results in many other forests around the world.
A way forward
Australia’s Traditional Custodians are rightly acknowledged as the continent’s first scientists. By living on and working with Country, they learned how it responded.
As we turn an historic page in forest management in parts of Australia, Western scientists could do well to learn from and partner with Traditional Owners to explore new ways to manage Country. Try new approaches. Learn from practice. And work together to figure out how best to heal Forest Country.
Jack Pascoe has received funding from the Australian Research Council. He is affiliated with the Biodiversity Council, Saltwater People, Conservation Ecology Centre and Back to Country.
Patrick Baker has received funding from the Australian Research Council, the Australian Centre for International Agricultural Research, and the Victorian government. He has also received funding to teach intensive short courses on forest dynamics to field staff of Local Land Services NSW and Forestry Corporation NSW. He has consulted for the NSW Office of the Chief Scientist and Engineer and the NSW Natural Resources Commission on issues related to native forest management.
Tom Fairman has received funding from the Victorian Government and the Australian Research Council. He is currently involved in research evaluating approaches to restoration undertaken by First Nations groups. He is a member of the Corner Inlet Landcare Group, Forestry Australia, the Gippsland Forest Dialogue, and the Gippsland Agroforestry Network.
There’s a community in Ontario called Dutton which, right now, seems appropriate given the number of times Peter Dutton has name-checked the Canadian province over the last 12 months.
In dozens of media interviews and speeches, Dutton (the opposition leader, not the township) has said Ontarians are getting cheap electricity because of their 20 nuclear reactors.
As global temperatures inch upwards year after year, the world’s glaciers retreat. These rivers of ice and the even larger ice sheets which cover Greenland and Antarctica are melting – and the melt is speeding up.
Glaciers and ice sheets have only a few species which can live on them, from ice worms to snow fleas and snow algae. When the ice melts, these species have to retreat with them.
But what happens to the areas the glaciers leave behind? Does life move in?
Our international team of researchers has spent the last decade investigating what happens to the newly uncovered ground as glaciers retreat further up mountain ranges. We tracked what’s happening at 46 retreating glaciers: from the Himalayas to the Andes, from the Arctic archipelago of Svalbard to as far south as New Zealand, and even tropical glaciers in Mexico.
What our new research has found is life quickly moves to colonise these new habitats, from microorganisms to hardy lichens and mosses, to pioneer species such as grasses. More plants arrive – and then, following them, come the animals. Over time, we’ve watched as new ecosystems emerged.
Life finds a way
When a glacier melts, what’s left behind is a barren landscape of bare rock and sediment. Over time, these areas gradually transform into a complex and diverse post-glacial ecosystem.
What we wanted to know was how this happens, how long it takes, and how life goes about colonising new habitat.
Between roughly the 14th and 19th centuries, the world was in the grip of the “Little Ice Age” – a period of moderate cooling largely affecting the northern hemisphere. During this period, many glaciers in this hemisphere expanded.
From the late 19th century onwards, human activities – especially the routine burning of fossil fuels – began to trap more heat and warm the planet, slowly at first but now accelerating.
We chose our glacial landscapes with care, selecting only those glaciers where we could accurately date the beginning of the retreat of the ice using a range of data sources, including topographical maps, field measurements, photographs, paintings, remote imaging and field data. Our team covered many parts of the world, but we did less sampling in polar regions.
We collected soil samples from more than 1,200 plots across our 46 glaciers and analysed them in the laboratory to track which species arrived when. We tracked ecosystem formation by analysing soil properties and nutrients and the evidence of carbon capture by plants. We also used environmental DNA sampling techniques to capture DNA traces left by animal species to gauge local biodiversity.
We could then cross-reference the arrival of species with when each glacier began to retreat.
What did we find? A surprisingly widespread pattern of ecosystem formation.
The first lifeforms to arrive were the smallest. Microorganisms such as bacteria, protists and algae colonise the ground. These tiny lifeforms can form surprisingly rich communities all by themselves.
It takes about a decade of colonisation by microorganisms before larger species can arrive. Some microorganisms can make minerals in the rocks available for other species.
Next comes hardy pioneer species such as lichens, mosses, and grasses able to tolerate tough conditions. Even though the ice has gone, these areas are still scoured by wind and cold.
After pioneer species grow and die, they leave behind organic material. This gradually enriches the thin soils. When there’s enough organic matter, more complex plants can take root. Larger animals arrived last, as herbivores need thriving plant communities to survive and predators need prey animals to eat.
How do different species form an ecosystem?
Ecosystems can be very simple through to hugely complex. For instance, on ice-free parts of the Antarctic peninsula, the ecosystem is dominated by mosses and hardy species of tardigrade and springtail.
What makes ecosystems become more complex?
As our research shows, the most important feature is time, rather than species interaction. As time passes, more new species are likely to colonise these post-glacial landscapes.
But it’s the interactions between organisms which makes ecosystems function.
Microorganisms often help pioneer plants by accelerating the development of fertile soils. How? Bacteria and fungi break down organic matter from dead plants into simpler compounds. This process creates humus, a rich, fertile component of soil which improves its structure and nutrient content.
In turn, plants create new habitat and food sources for animals. Animals begin to interact with each other, through predator-prey relationships such as arctic foxes and rabbits, or as “ecosystem engineers” such as earthworms, who pave the way for more animals by eating dead plant matter and improving nutrient availability in the soil.
Even in seemingly barren environments, the way organisms interact with each other and their environment can be extremely complex and rich.
Levan Tielidze was supported by the Australian Research Council (ARC) Special Research Initiative (SRI) Securing Antarctica’s Environmental Future (SR200100005).
We now have a dizzying array of heating technologies to consider, besides the fire that warmed our ancestors.
Salespeople will highlight any number of features and minor conveniences. You will be made aware of limited-offer discounts, product warranties, trends in certain Nordic countries, or their low cost (at least in the short-term). What you are less likely to read on the box is, well, the stuff that really matters: the long-term effects on your health and the health of your family, your neighbours and the environment.
Yes, a heater should keep you warm affordably. After all, a warm home is vital for your health. But would you run a heater that you knew was increasing the likelihood of your child developing asthma, your partner developing lung cancer, and your neighbour or your grandparent suffering a stroke or heart attack?
Many peer-reviewed studies have found domestic heating to be a major source of air pollution and of ill health in Australia. So which heaters are high-risk and which are low-risk? Let’s consider, firstly, the most dangerous heaters.
Extreme-risk heaters
Two rules reduce the risks:
never burn anything (wood, gas or other fuel) in your home without adequate ventilation such as a chimney, exhaust or flue
never use an outdoor appliance (heater, cooker, barbecue) inside.
Concerningly, a 2022 Asthma Australia survey found 7% of Australians used an unflued gas heater.
When gas or other fuel is burnt indoors it releases a range of particles and toxic gases. Most dangerous of all is carbon monoxide (CO). This colourless, odourless gas can build up in unventilated homes, resulting in serious poisoning and death.
A recent case of carbon monoxide intoxication left three people unconscious in a Sydney home after an outdoor barbecue was used inside as a heater. Outdoor heaters, cookers and barbecues are especially potent sources of carbon monoxide and should never be brought inside.
If you have a gas appliance in your home, even if it is ventilated, install a carbon monoxide alarm for as little as $30.
The evidence is now very clear: wood heater smoke is a potent source of air pollution and significant cause of ill-health in Australia.
The more often you burn, the greater the risk. One large population study found even infrequent wood heater use (30 days or more each year) increases the risk of lung cancer by 68%.
Wood heaters spill smoke into the home when refuelling. They also suck smoke from outside back into the home as air is drawn up the chimney.
If you can smell your wood heater, it is harming your health and exposing you to a toxic mix of particles and gases.
For the wider community, the cumulative health impacts of wood heaters are significant.
Less than 10% of Australian households use a wood heater. Yet they are the largest source of particulate air pollution in most Australian cities and towns, including Sydney, Melbourne, Canberra, Adelaide and Hobart. Even in temperate Sydney, wood heaters emit more of this pollution than all the cars, trucks, boats and buses combined, and more than coal-fired power stations and industry.
If you can smell your wood heater it is harming your health.KingTa/Shutterstock
Moderate-risk heaters
Evidence suggests there is no “safe” level of air pollution, with health effects seen at very low levels.
Flued gas heaters, which vent exhaust gases out of the home, can still expose residents to PM2.5, nitrogen dioxide (NO2), carbon monoxide and formaldehyde. Over time, this can have a range of health impacts, including worsening asthma and respiratory symptoms.
Even ducted gas heating, which has an external heating unit, has the problem that burning gas adds to greenhouse gas emissions.
As Australia transitions to a zero-carbon society, some states and territories are phasing out installation of new wood heaters, such as in the ACT, and gas connections, such as in Victoria. Subsidies to help people replace unhealthy heaters are excellent investments in the environment, public health and health equity.
Healthy heaters
Ultimately, heaters that do not rely on burning fuel inside the home are the safest, and often more affordable, heating option.
A well-maintained reverse-cycle air conditioner, sometimes called a heat pump, actually cleans the air inside your home.
These air conditioners have the additional benefit of cooling your home in summer. As heatwaves become more severe and frequent, efficient cooling is increasingly important for health.
As for affordability, an efficient reverse-cycle air conditioner can be up to seven times as efficient as a gas wall heater in the energy it uses for a given amount of heat.
There are many other electric heating technologies – such as fan heaters, oil column heaters, panel heaters, or infrared heaters – that do not release toxins into the home.
Heater manufacturers are often reluctant to talk about the health impacts of their products, and regulators are slow to catch up with the science.
By thinking about heating in terms of health, you can make your home safer for yourself and the people around you.
After all, there’s nothing cosier than a healthy home.
Correction: This article has been updated to correct a reference to ducted gas heating exposing residents to toxins indoors. It should have referred to flued gas heaters.
Christine Cowie has received funding from the NHMRC, a Perpetual Impact grant, a NSW Health Department project grant, a NSW EPA project grant, a Commonwealth Government project grant and a SWC project grant. She is an affiliate of the Centre for Safe Air (CSA), Expert Partner for Global Cooksafe Coalition (Australia Program), NFP (Nov 2023-), member of Clean Air Society of Australia and NZ (CASANZ), and member of the International Society for Environmental Epidemiology.
Bill Dodd does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
Central General Staff militant group previously said Cop16 event scheduled for October in Cali ‘would fail’
A dissident rebel group has backed down from its threat to disrupt the UN biodiversity summit in Colombia later this year.
The Central General Staff (EMC), a guerrilla faction that rejected the country’s 2016 peace agreement, said on Wednesday it would order its militants not to target the Cop16 negotiations that are due to begin in Cali in October.
