Craig Nitschke, University of Melbourne; Andrew Robinson, University of Melbourne; Melissa Fedrigo, University of Melbourne; Patrick Baker, University of Melbourne, and Raphael Trouve, University of Melbourne
The Federal Court recently ruled that a timber harvesting company couldn’t log potential habitat of the critically endangered Leadbeater’s possum.
This decision led to the immediate protection of more Leadbeater’s possum habitat and will lead to further habitat set aside over the next ten years as native timber harvesting is phased out in Victoria.
But these short-term, site-based measures will not guarantee the long-term conservation of this iconic Victorian species.
Our new study modelled changes in forests over the next 250 years, focusing on 280,000 hectares of Victoria’s Central Highlands, home to the majority of remaining Leadbeater’s possums.
We looked at different scenarios of how both climate change and timber harvesting might play out. And we identified three important findings.
First, Leadbeater’s possum habitat is dynamic. It’s transient across the landscape over time as disturbances, such as bushfires, continually change the spatial distribution of hollow-bearing trees and young forests.
Second, while timber harvesting poses a local-scale threat, at a larger scale – across hundreds of thousands of hectares – bushfire poses the greatest threat to the species’ habitat.
Last, we found less than half of the area within current parks, reserves, and timber harvest exclusion zones provided stable long-term habitat for Leadbeater’s possum over the next century.
Future habitat scenarios
We used a set of four scenarios to explore how climate change and timber harvesting impact long-term habitat availability by focusing on the where and when hollow-bearing trees and dense understorey are found in the landscape.
The scenarios included projecting current climate conditions, and projecting a 2℃ rise in average annual temperature with a 20% reduction in yearly rainfall.
For each of these climate scenarios, timber harvesting at current harvesting rates was either excluded or allowed in areas zoned for timber production.
Bushfires drive long-term habitat loss
Our simulations showed bushfire, not logging, is the biggest threat to habitat availability for Leadbeater’s possum in the Central Highlands. As the cumulative area burnt by fire increased, the quantity and quality of Leadbeater’s possum habitat decreased.
Tthe 2009 Black Saturday fires burned almost half of its habitat, causing its conservation status to jump from endangered to critically endangered.
Bushfires have always been part of Australian landscapes and many species, including Leadbeater’s possum, have evolved alongside them. Eleven years later, Leadbeater’s possum are now recolonising areas burned in the 2009 bushfires.
But as climate change increases the frequency and scale of bushfires, our models suggest the Central Highlands landscape may support less suitable habitat.
Timber harvesting is less of a threat
While timber harvesting compounds the impacts of bushfires on Leadbeater’s possum habitat, across the landscape the effect is small in comparison. Timber harvesting reduced suitable habitat by only 1.4% to 2.3% over 250 years compared to scenarios without harvesting.
Within a coupe (the area of forest harvested in one operation), timber harvesting immediately reduces nesting and foraging habitat. But foraging habitat returns within 10 to 15 years and can be recolonised by Leadbeater’s possum – as long as nesting sites are nearby.
Protecting vegetation around waterways, in particular, was critical for the development and survival of hollow-bearing trees in an increasingly fire-prone landscape.
But while timber harvesting had much smaller impacts than bushfires, the two did interact. Over time, the cumulative impacts of timber harvesting and bushfire homogenised forest structure across the landscape, leading to smaller patches of habitat that were less connected.
This increases the risk of local extinction for populations of Leadbeater’s possum living in these patches.
We need dynamic conservation areas
A core question for the conservation of any threatened species is: how well does the network of protected areas protect the species?
Our modelling framework meant we could test whether current areas set aside for Leadbeater’s possum conservation actually provide long-term protection.
Over the next 100 years, less than 50% of existing parks, reserves and timber-harvest exclusion zones will provide continuous habitat for Leadbeater’s possum due to climate change.
However, we also identified approximately 30,000 hectares of forest outside the current network of protected areas that can provide stable habitat for Leadbeater’s possum over the next century.
It’s vital we put protection zones into the areas possums are likely to migrate to as the climate changes. These areas should be a priority for conservation efforts.
A new conservation strategy
Historically, conservation planning has taken a static, site-based approach to protecting species.
This approach is doomed to fail in dynamic landscapes – particularly in fire-prone landscapes in a warming climate. For conservation planning to be successful, we need coordinated forest, fire, and conservation management that accounts for these dynamics across the whole landscape, not just in individual locations.
We need a vision for how to make our landscapes more resilient to the growing threat of climate change and provide better protection for the unique flora and fauna that inhabit them.
This will require government agencies responsible for land management and conservation to coordinate current management activities across tenures, while simultaneously implementing future-focused conservation planning. Our landscape-modelling approach provides a first step in that direction.
Craig Nitschke, Associate Professor – Forest and Landscape Dynamics, University of Melbourne; Andrew Robinson, Managing Director for Biosecurity Risk Research, University of Melbourne; Melissa Fedrigo, Remote Sensing Scientist and Ecological Modeller, University of Melbourne; Patrick Baker, ARC Future Fellow and Professor of Silviculture and Forest Ecology, University of Melbourne, and Raphael Trouve, Post-Doctoral Research Fellow Ecosystem And Forest Sciences, University of Melbourne
The Federal Court last week ruled that VicForests – a timber company owned by the Victorian government – breached environmental laws when they razed the habitat of the critically endangered Leadbeater’s possum and the vulnerable greater glider.
Environmentalists welcomed the judge’s decision, which sets an important legal precedent.
Under so-called “regional forest agreements”, a number of logging operations around Australia are exempt from federal environment laws. This effectively puts logging interests above those of threatened species. The court ruling narrows these exemptions and provides an opportunity to create stronger forestry laws.
A legal loophole
Since 1971, the Leadbeater’s possum has been the faunal emblem of Victoria. But only about 1,200 adults are left in the wild, almost exclusively in the Central Highlands region.
Official conservation advice identifies the greatest threat to the species as habitat loss and fragmentation caused by the collapse of hollow-bearing trees, wildfire, logging and climate change.
Australia’s federal environmental laws require environmental impact assessment of any action likely to significantly impact a matter of national environmental significance, such as a listed threatened species.
But thanks to exemptions under regional forest agreements, logging has continued in the Central Highlands – even in the aftermath of this summer’s devastating bushfires.
So what are regional forest agreements?
Regional forest agreements were designed as a response to the so-called “forest wars” of the 1980s and 1990s.
In 1995, after logging trucks blockaded parliament, then Prime Minister Paul Keating offered a deal to the states: the federal government would accredit state forest management systems, and in return federal law would no longer apply to logging operations. Drawing up regional forest agreements between state and federal governments achieved this.
Between 1997 and 2001, ten different agreements were signed, covering logging regions in Victoria, New South Wales, Tasmania and Western Australia. These agreements were for 20 years, which means many have now either expired and been renewed or extended, or are about to expire.
The agreements are supposed to satisfy a number of conditions. This includes that they’re based on an assessment of environmental and social values of forest areas. They should also provide for the ecologically sustainable management and use of forested areas, and the long-term stability of forest and forest industries.
But conservation experts argue the agreements have failed both to deliver certainty to forestry operations or to protect environmental values and ensure the conservation of biodiversity.
History of the court case
The legal proceedings against VicForests were initiated in 2017 by Friends of the Leadbeater’s Possum, a small community group which relied on crowd funding to cover legal costs.
Initially, the group argued Victoria’s failure to undertake a required review of the Central Highlands regional forest agreements every five years meant the usual exemption to federal environment laws should not apply.
But in early 2018, Justice Mortimer ruled against this. But she also rejected VicForests’ arguments that any operation in an area covered by a regional forest agreement is automatically exempt from federal law.
She ruled that the logging operations will only be exempt from federal law if they comply with Victoria’s accredited system of forest management. This includes the requirements for threatened species, as specified in official action and management plans.
In response to this ruling, Friends of the Leadbeater’s Possum reformulated their claim.
They argued logging operations in 66 coupes (small areas of forest harvested in one operation) didn’t meet these requirements for threatened species, and so the exemption from federal laws didn’t apply.
The court ruling
In her ruling last week, the judge found VicForests unlawfully logged 26 coupes home to the Leadbeater’s possum and greater glider, and that logging a scheduled 41 other sections would put them at risk.
The court found the company breached a number of aspects of the Code of Practice for Timber Production 2014. This code is part of the Victorian regulatory system accredited by the regional forest agreement.
In particular, VicForests had not, as required, applied the “precautionary principle” in planning and conducting logging operations in coupes containing the greater glider.
Nor had VicForests developed a comprehensive forest survey system, or engaged in a careful evaluation of management options to avoid dangers to these threatened species.
These failures meant the logging operations were not covered by the exemption from federal laws. As such, the court found VicForests had breached federal environmental law, as the logging operation had, or were likely to have, a significant impact on the two threatened species.
This case will have clear implications for logging operations governed by regional forest agreements.
In fact, the timber industry has called for state and federal governments to urgently respond to the case, and clarify the future of regional forest agreements.
Arguably, logging operations conducted under a regional forest agreement can no longer rely on the exemption from federal environmental laws if those operations don’t comply with the state regulatory frameworks accredited under the regional forest agreements, especially provisions that protect threatened species.
And while making logging operations subject to federal environmental laws is a good thing, it’s not enough. Federal environmental laws are weak and don’t prevent species extinctions.
In any case, the result is the perfect opportunity for state and federal governments to rethink forest management. That means properly taking into account the ongoing threats to threatened species from climate change, wildfires and habitat loss.
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.
A double disturbance
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”.
It doesn’t add 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
The Victorian government’s logging business is cutting native forests on steep slopes, in an apparent rule breach that threatens water supplies to Melbourne and rural communities.
Our research indicates that across vital water catchments in the Central Highlands of Victoria, state-owned VicForests is logging native forest on slopes steeper than is allowed under the code of practice. Logging also appears to be occurring in other areas supposedly excluded from harvesting.
Logging operations are prohibited from taking trees from slopes steeper than a certain gradient, because it can lead to soil damage which compromises water supplies. There are far better commercial alternatives to this apparent contravention of the rules, which must immediately cease.
Logging on steep slopes matters
Water catchments are areas where the landscape collects water. They are defined by natural features such as mountain ridgelines and valleys. Rain drains into rivers and streams, which supply water to reservoirs.
Forest cover protects the soil in water catchments by preventing erosion and other damage which can pollute water.
Areas that provide water for drinking, agriculture and irrigation are known in Victoria as special water supply catchments. Under the state’s Code of Forest Practice, logging in these catchments is prohibited on slopes steeper than 30 degrees (or 25 degrees in some catchments). VicForests claims it does not log trees on such slopes.
We analysed slopes across multiple special water supply catchments. We first examined the relationships between slope and logging disturbance using data from the Victorian government, Geoscience Australia, and the European Space Agency. To confirm the results, we visited multiple sites in the Upper Goulburn catchment, which supplies water to Eildon Reservoir, to measure the slopes ourselves.
We found logging in many areas steeper than 30 degrees. In larger catchments such as the Upper Goulburn, around 44% of logged areas contained slopes exceeding this gradient. In many instances, logged slopes were far steeper than 30 degrees and some breaches covered many hectares.
In the Thomson, Melbourne’s largest water supply catchment, 35% of logged areas contained slopes steeper than 30 degrees.
We also found areas that should have been formally excluded from logging but where the forest had been cut. Many of these exclusion zones were around steep slopes. In the Upper Goulburn catchment, nearly 80% of logged areas contained exclusion zones that should not have been cut.
Why is this happening?
Last week, VicForests rejected our allegations of slope breaches. VicForests claimed it was complying with a rule under which 10% of an area logged can exceed 30 degrees. This rule applies to general logging areas; our interpretation is this exemption does not apply to the special water supply catchments.
Forest on steep and rugged terrain is economically marginal for wood production because the trees are relatively short and widely spaced. Almost all timber from these areas is pulpwood for making paper.
So why are such areas being logged at the risk of compromising the water catchments that supplies Melbourne and regional Victoria?
We suspect pressure to log steep terrain is tied to the Victorian government’s legal obligation to provide large quantities of pulp logs for making paper until the year 2030 (coincidentally the year the government plans to phase out native forest logging).
This pressure is reflected in recent reductions in log yields. Some commentators have blamed efforts to protect the critically endangered Leadbeater’s possum for this trend. However, only 0.17% of the 1.82 million hectares of forest allocated to VicForests for logging has been taken out of production to protect this species.
In our view, other possibilities for declining yields are past over-cutting and bushfires. VicForests failed to take into account the effects of fire on its estimates of sustained timber yield – despite some of Victoria’s forests being some of the world’s most fire-prone environments.
There are alternatives
Pulp logs sourced from native forests is not a commercial necessity; there are viable alternatives. Victorian hardwood plantations produced 3.9 million cubic metres of pulp logs last year. Most of this was exported.
If just some of these logs were processed in Victoria, it would be enough to replace the pulpwood logged from native forests several times over. Plantation wood is better for making paper than native forest logs, and processing the logs in Victoria would boost regional employment.
Degrading soil and water by logging steep terrain is not worth the short-term, marginal gain of meeting log supply commitments, especially when there are viable alternatives. The Victorian government must halt the widespread breaches of its own rules.
In a statement, VicForests said it “strongly rejects” the allegations raised by the authors.
In addition to the refutations included in this article, the company said:
Any concerns about its practices should be referred to the Office of the Conservation Regulator
VicForests does very little harvesting in catchments, where restrictions are in place
In the Thompson catchment, VicForests only harvests on average 150ha a year out of about 44,000ha in the catchment – which is 0.3%, or around 3 trees in 1000
VicForests only asks contractors to harvest on slopes if it complies with regulation.
David Lindenmayer, Professor, The Fenner School of Environment and Society, Australian National University and Chris Taylor, Research Fellow, Fenner School of Environment and Society, Australian National University
The effects of European consumption are being felt in Brazil, driving disastrous deforestation and violence.
But the destruction can end if the European Union demands higher environmental standards on Brazilian goods. Hundreds of scientists and Indigenous leaders agree: the time to act is now, before it’s too late.
In an open letter published today in the journal Science, more than 600 scientists from every country in the European Union (EU) and 300 Brazilian Indigenous groups asked the EU to demand tougher standards for Brazilian imports.
The letter calls on the EU to ensure a trade deal with Brazil respects human rights and the natural world.
Crucially, this can be done without harming Brazil’s agriculture, if already cleared land is used to its full potential. Indeed, in the long term, farming in the region depends on the rains brought by healthy forests.
Destruction of the Amazon under Bolsonaro
Brazil’s Indigenous people and the forests they protect are facing annihilation.
Controversial president Jair Bolsonaro is opening the Amazon rainforest to business and threatening Indigenous people who stand in the way. In his first hours in office, Bolsonaro gave power over Indigenous land to the Ministry of Agriculture, which is widely seen to be controlled by corporate lobbyists.
As Bolsonaro scraps environmental laws, forests are being cut down faster than they have been in years. And the EU is helping drive this carnage: more than a football field of Brazilian rainforest is cut down every hour to produce livestock feed and meat for Europe.
Although the situation may seem dire for the Amazon and its inhabitants, ongoing trade talks provide a chance to act.
Billions of euros flow to Brazil from business with the EU, its second-largest trade partner. Goods flowing in the other direction include environmentally and socially destructive livestock feed (usually soy grown on deforested land) which enters the EU on a tariff-free basis. Right now, European consumers have no way of knowing how much blood is actually in their hamburger. The ongoing EU-Brazil trade talks are therefore a powerful opportunity to curb Bolsonaro’s appetite for destruction.
It is hard to overstate the case for strong action from Europe. People in Brazil – especially Indigenous and local communities – are being violently repressed when trying to defend their land against agricultural and mining companies.
Brutal repression and environmental catastrophe
This violence has reached record levels under Bolsonaro, with at least nine people murdered so far in April 2019. And genocide is a real possibility if nothing is done to protect Indigenous people and their land.
Alarmingly, Bolsonaro has even said:
It’s a shame that the Brazilian cavalry hasn’t been as efficient as the Americans, who exterminated the Indians.
On top of the horrifying assault on Brazil’s original inhabitants, demolishing the country’s forests, savannas and wetlands would have devastating consequences for the world.
If the Amazon rainforest alone is destroyed, the resulting carbon emissions could make it extremely difficult to limit global warming to less than two degrees. Burning fossil fuels is often seen as the only culprit in climate breakdown, but tropical deforestation is the second-largest source of carbon emissions in the world.
Even losing part of the Amazon could cause a tipping point where the forests no longer create enough rain to sustain themselves. This would cause droughts that would drive many species to extinction, devastate farming in the region and likely cause further violence.
We must act now
We are not just at an ecological tipping point, but a social one, too. The world is waking up to the risks posed by destroying our climate and natural world. Climate change is considered the number one security threat by Brazilian people and by many European nations.
Europeans believe neither their country nor the EU is doing enough to protect our planet’s life support systems. As protests flare up in Europe over environmental crises, climate change will be a key issue in the upcoming European elections.
As scientists, we use emotive words carefully. But our open letter calls on the EU to take urgent action because we are terrified of the consequences of Brazilian deforestation, both locally and globally.
We beg the EU to stand up for its citizens’ values and our shared future by making sure trade with Brazil protects, rather than destroys, the natural world on which we all depend.
Victoria has some of the most carbon-dense native forests in the world. Advocates for logging these forests often argue that wood products in buildings and furniture become long-term storage for carbon.
However, these claims are misleading. Most native trees cut down in Victoria become woodchips, pulp and pallets, which have short lifespans before going to landfill. In landfill, the wood breaks down and releases carbon back into the atmosphere.
On the other hand, our evolving carbon market means Australia’s native forests are extremely valuable as long-term carbon stores. It’s time to recognise logging for short-lived wood products is a poor use of native forests.
The problem with logging native forests
These forests can store up to 1,140 tonnes of carbon per hectare for centuries.
But around 1.82 million hectares of Victorian native forests are allocated to the government’s logging business, VicForests.
VicForests claims logging is the only market for the large area of native forest allocated to it. In other words, its forests are exclusively valued as timber asset, in the same way a wheat crop would be exclusively valued for wheat grain production.
In Victorian native forests, industrial scale clearfell logging removes around 40% of the forest biomass for logs fit for sale.
The remaining 60% is debris, which is either burned off or decomposes – becoming a major source of greenhouse gas emission.
Myth one: storing carbon in wood products
The first myth we want to address is logging native forests is beneficial because the carbon is stored in wood products. This argument depends on the proportion of forest biomass ending up in wood products, and how long they last before ending up in landfill.
On average, logs suitable to be sawn into timber make up only an average 35% of total logs cut from Victorian native forests.
Of this 35%, sawmills convert less than 40% into sawn timber for building and furniture. Offcuts are woodchipped and pulped for paper manufacturing, along with sawdust sold to chicken broiler sheds for bedding.
Sawn timber equates to 14% of log volume cut from the forest. The remaining 84% of logs cut are used in short-lived and often disposable products like copy paper and pallets.
The maximum lifespan of a timber pallet is seven years. At the end of their service, timber pallets are sent to landfill, chipped for particleboard, reused for landscape mulch or burnt for energy generation.
Longer-lived wood products, such as the small proportion of native timber used in building and furniture, have a lifespan of around 90 years. These wood products are used to justify logging native forests.
But at the end of their service life, the majority of these wood products also end up in landfill.
In fact, for the 500,000 tonnes of wood waste generated annually from building, demolition and other related commercial processes in Victoria, over two thirds end up in landfill, according to a Sustainability Victoria report.
Myth two: the need to log South East Asian rainforests
A second myth is using logs from Victorian native forests will prevent logging and degradation of rainforests across South East Asia, particularly for paper production.
This is patently absurd. The wood from the Victorian plantation sector – essentially timber farms, rather than trees growing “wild” in native forests – could replace native forest logs used for paper manufacturing in Victoria several times over.
In fact, in 2016-17 89% of logs used to make wood pulp (pulplogs) for paper production in Victoria came from plantation trees, with the majority of hardwood logs exported.
And Australia is a net exporter by volume of lower-value unprocessed logs and woodchips.
Processing pulplogs from well managed plantations in Victoria instead of exporting them would give a much needed jobs boost for local economies.
With most of these plantations established on previously cleared farmland, they offer one of the most robust ways for the land use sector to off-set greenhouse gas emissions.
The time is right for Australian governments to develop a long-term carbon storage plan that includes intact native forests.
Logging results in at least 94% of a forest’s stored carbon ending up in the atmosphere. A maximum of 6% of its carbon remains in sawn timber, for up to 90 years (but typically much shorter). This is patently counterproductive from a carbon-storage point of view.
State-owned forest management companies, such as VicForests, can transition away from the timber business and begin managing forests for carbon storage. Such a concept is not new – the federal government has already approved a way to value the carbon storage of plantations.
The same must now be developed to better protect native forests and the large amounts of carbon they can store.
Chris Taylor, Research Fellow, Fenner School of Environment and Society, Australian National University and David Lindenmayer, Professor, The Fenner School of Environment and Society, Australian National University
The 2009 Black Saturday fires burned 437,000 hectares of Victoria, including tens of thousands of hectares of Mountain Ash forest.
As we approach the tenth anniversary of these fires, we are reminded of their legacy by the thousands of tall Mountain ash “skeletons” still standing across the landscape. Most of them are scattered amid a mosaic of regenerating forest, including areas regrowing after logging.
But while we can track the obvious visible destruction of fire and logging, we know very little about what’s happening beneath the ground.
In a new study published in Nature Geoscience, we investigated how forest soils were impacted by fire and logging. To our surprise, we found it can take up to 80 years for soils to recover.
Decades of damage
Soils have crucial roles in forests. They are the basis for almost all terrestrial life and influence plant growth and survival, communities of beneficial fungi and bacteria, and cycles of key nutrients (including storing massive amounts of carbon).
To test the influence of severe and intensive disturbances like fire and logging, we compared key soil measures (such as the nutrients that plants need for growth) in forests with different histories. This included old forests that have been undisturbed since the 1850s, forests burned by major fires in 1939, 1983 and 2009, forests that were clearfell-logged in the 1980s or 2009-10, or salvage-logged in 2009-10 after being burned in the Black Saturday fires.
We found major impacts on forest soils, with pronounced reductions of key soil nutrients like available phosphorus and nitrate.
A shock finding was how long these impacts lasted: at least 80 years after fire, and at least 30 years after clearfell logging (which removes all vegetation in an area using heavy machinery).
However, the effects of disturbance on soils may persist for much longer than 80 years. During a fire, soil temperatures can exceed 500℃, which can result in soil nutrient loss and long-lasting structural changes to the soil.
We found the frequency of fires was also a key factor. For instance, forests that have burned twice since 1850 had significantly lower measures of organic carbon, available phosphorus, sulfur and nitrate, relative to forests that had been burned once.
Sites subject to clearfell logging also had significantly lower levels of organic carbon, nitrate and available phosphorus, relative to unlogged areas. Clearfell logging involves removing all commercially valuable trees from a site – most of which are used to make paper. The debris remaining after logging (tree heads, lateral branches, understorey trees) is then burned and the cut site is aerially sewn with Mountain Ash seed to start the process of regeneration.
Logging compounds the damage
The impacts of logging on forest soils differs from that of fire because of the high-intensity combination of clearing the forest with machinery and post-logging “slash” burning of debris left on the ground. This can expose the forest floor, compact the soil, deplete soil nutrients, and release large amounts of carbon dioxide into the atmosphere.
Predicted future increases in the number, frequency, intensity and extent of fires in Mountain Ash forests, coupled with ongoing logging, will likely result in further declines in soil nutrients in the long term. These kinds of effects on soils matter in Mountain Ash forests because 98.8% of the forest have already been burned or logged and are 80 years old or younger.
To maintain the vital roles that soils play in ecosystems, such as carbon storage and supporting plant growth, land managers must consider the repercussions of current and future disturbances on forest soils when planning how to use or protect land. Indeed, a critical part of long-term sustainable forest management must be to create more undisturbed areas, to conserve soil conditions.
Specifically, clearfell logging should be limited wherever possible, especially in areas that have been subject to previous fire and logging.
Ecologically vital, large old trees in Mountain Ash forests may take over a century to recover from fire or logging. Our new findings indicate that forest soils may take a similar amount of time to recover.
Giant eucalypts play an irreplaceable part in many of Australia’s ecosystems. These towering elders develop hollows, which make them nature’s high-rises, housing everything from endangered squirrel-gliders to lace monitors. Over 300 species of vertebrates in Australia depend on hollows in large old trees.
These “skyscraper trees” can take more than 190 years to grow big enough to play this nesting and denning role, yet developers are cutting them down at an astounding speed. In other places, such as Victoria’s Central Highlands Mountain Ash forests, the history of logging and fire mean that less than 1.2% of the original old-growth forest remains (that supports the highest density of large old hollow trees). And it’s not much better in other parts of our country.
David Lindenmayer explains how these trees form, the role they play – and how very hard they are to replace.
Continued logging in Melbourne’s water catchments could reduce the city’s water supply by the equivalent of 600,000 people’s annual water use every year by 2050, according to our analysis.
We calculated water lost due to logging in the Thomson Catchment, which is the city’s largest and most important water supply catchment. Around 60% of Melbourne’s water is stored here.
Since the 1940s, 45% of the catchment’s ash forests (including mountain and alpine ash forest) have been logged. There are plans to log up to a further 17% of these forests under the VicForest’s existing logging plan.
Past logging in the ash forests has reduced the Thomson Catchment’s water yield, which is the amount of water that flows through the catchment, by 15,000 megalitres (a megalitre is a million litres) each year. This equates to around 9% of water yield from ash forests across the catchment.
By 2050, continued logging in these forests at the current rates could increase this loss to 35,000 megalitres each year, or 20% of water yield. This will be equal to the water use of around 600,000 people every year, based on estimated water use of 161 litres per person each day.
Why forests are important for water supply
The city of Melbourne has some of the best quality water in the world. A key reason for this is that the city’s first water infrastructure planners closed many of the key water catchments to intensive human disturbance, such as logging.
But there also can be competition for water between different land uses in catchments that are not closed and open to logging. Indeed, it has long been known that logging can significantly reduce the amount of water produced from forests, especially those close to Melbourne.
Research on forest hydrology shows that the amount of water yielded from ash forests is related to forest age. Catchments covered with old-growth ash forests yield almost twice the amount of water each year as those covered with young forests aged 25 years. This is because evapotranspiration, the process by which trees transpire water into the atmosphere as well as evaporation from the surrounding land surface, is higher in young forests compared with older forests.
Up to 200,000 trees per hectare germinate following logging or an intense fire which burns the whole stand. Intense competition between young trees results in rapid growth rates along with increased evapotranspiration. As the forest matures, the trees thin out, and after 200 years, an ash forest can have less than 50 trees per hectare. These older ash forests release more water back into the catchment.
With logging occurring every 60-120 years, large areas of ash forest are kept in a high evapotranspiration stage of growth, therefore releasing less water back into the catchment.
Perhaps the losses in water yield could be justified if the value of the timber and pulpwood produced from logging exceeded the value of water. However, previous research has shown that the water in these areas is 25.5 times more valuable than the timber and pulpwood from ash forests.
What can the Victorian government do?
The ash forests in the Thomson Catchment are logged primarily for paper manufacturing. Under the Forest (Wood Pulp Agreement) Act 1996, the Victorian government is bound to supply Australia’s largest pulp and paper mills at Maryvale, owned by the Nippon Paper Group, with at least 350,000 cubic metres of native forest logs each year. The Thomson Water Supply Catchment is allocated for logging under this Act.
If logging was stopped in the catchment, what is the alternative for these paper mills? The answer is to source wood from current plantations. In 2017, Victoria produced 3.9 million cubic metres of logs from plantations. This could supply the pulp and paper mills at Maryvale several times over.
A challenge facing Victoria’s forest industry is the loss of jobs. One major factor in this is out-of-state processing. Australia tends to import lower volumes
of more processed and higher value wood products, including printing and writing paper. By contrast, higher volumes of less processed and lower value wood products, such as woodchips and unprocessed logs – largely from plantations, are exported.
Redirecting plantation sourced logs and woodchips from export markets to domestic processing can address some of these problems. In fact, detailed analysis suggests doing this would have an overall positive economic impact for Victoria.
Stopping logging in the Thomson Catchment and sourcing instead from well managed plantations could both boost water supply and create more jobs. Of course, some jobs would be lost for people who log from the catchment, but this would be more than compensated for by employment in the plantation processing sector.
The first Wood Pulp Agreement Act of 1936, which legislated supply of pulplogs from Victorian state forest to earlier paper manufacturers in Maryvale, featured a clause stating logging was to cease following the designation of the Thomson Catchment in 1967. This has clearly not occurred. In fact 63% of logging in the ash forests across the catchment has occurred since 1967.
The Thomson Catchment is the only one of Melbourne’s large water supply catchments open to logging. Given the critical importance of the Thomson Catchment, our work clearly indicates the Victorian government needs to cease logging and prioritise the supply of water to the people of Melbourne.
David Lindenmayer, Professor, The Fenner School of Environment and Society, Australian National University and Chris Taylor, Research Fellow, Fenner School of Environment and Society, Australian National University