The world’s forests play critical roles in water cycles, carbon storage, wood production, and biodiversity conservation. How forests are managed can have profound impacts on these roles, particularly where uses such as wood production conflict with other goals such as the protection of biodiversity, the maintenance of carbon stocks or the supply of water for human consumption.
Long-term maintenance of the range of values of natural forests is a key part of ecologically sustainable forest management.
Whilst ecologically sustainable forest management is the goal of management agencies in many parts of the world, it can be difficult to achieve for a wide range of reasons, particularly the array of ecological, economic, silvicultural, social and other factors that need to be considered.
Ecologically sustainable forest management is particularly difficult to achieve when wood production is based on principles of maximum sustained yield or the highly regulated forest concept.
The Concept and Major Problem of Regulated Forest
The regulated forest was an abstraction and an attempt to rationalise nature and make it knowable, calculable and visible. Strict application of this simple equation would result in roughly equal areas of each age class in a given ecosystem.
This management strategy has at its core, the aim of maximising economic benefits as well as the output of forest products that can theoretically be sustained over time. The ultimate objective is the perpetual, even flow of wood products for a forest industry.
A major problem with the regulated forest concept in forestry is that it is focuses on resource exploitation and ignores the inherent social and environmental complexities of forests.
It also ignores uncertainty that may arise from measurement error, natural variation that affects the distribution and abundance of the resource (e.g., the impacts of disturbance on wood stocks, such as fire) and a lack of understanding of the ecology of the species.
Failure to account for stochasticity or other factors means that estimates of sustained yield do not have sufficient ‘ecological margins’ to accommodate such impacts on the stock available for logging.
A further problem with the regulated forest approach is that it focuses almost exclusively on wood production, and other values, including key ecosystem services, are given limited consideration, thereby contravening the overarching objectives of ecologically sustainable forest management.
The regulated forest was often placed under the management of centralised forest government bureaucracies.
In some cases, such as in Australia, original centralisation of forestry was undertaken to address other issues of unsustainable practices such as widespread forest clearing for agriculture and grazing.
The centralisation of forestry was a central tenet of empire forestry. As colonialism expanded across Africa, Asia, Australia and the Americas throughout the 18th and 19th centuries, centralised colonial bureaucracies assumed control over vast forest areas, often excluding local people from their lands and suppressing traditional forest institutions.
The tenure of forests changed from local communities to distant state agencies. Government at a distance became the model of management. Specific types of knowledge and techniques were imposed on forests to make them visible, calculable and therefore exploited by distant agencies. The successors of these colonial regimes remain in place to this day in many parts of the world.
A landscape-scale and decentralised approach to forest management is sometimes suggested as a way to balance different (and often competing) forest values.
Under such an approach, a diversity of management strategies is employed in which different values are prioritised in different parts of landscapes across different communities, theoretically enabling a much wider array of values to be maintained across the broader forest estate.
For example, biodiversity and key ecosystem processes may be maintained in the face of ongoing wood production. The engagement of civil society in such a context can provide for a broader basis in knowledge about forest ecosystems, which can assist in more adaptive approaches to forest management.
However, historic forms of centralised governance have often excluded local stakeholders, therefore leading to increasing conflict around forest management decisions.
In this paper, we discuss how a legacy of past forest management practices, including adoption of the normal or regulated forest model for maximum sustainable timber yields, can preclude attempts to diversify future forest management.
We support our discussion with a case study on the mountain ash (Eucalyptus regnans) forests of the Central Highlands of Victoria (southeastern Australia).
New policies are urgently required to reform forest governance and rapidly transition industrial wood production away from native forests dominated by mountain ash, toward well managed plantations and non-threatened forest ecosystems.
This will spare the mountain ash ecosystem from industrial wood production with decentralised conservation strategies forming an important component of forest management. Wood production would then be transitioned into other areas that include sustainably managed plantations, and agroforestry.
Our detailed case study of mountain ash forests provides some important general lessons about the pitfalls of a focus on an intensively regulated and centralised forest-based management on maximum yield principles and its implications for diversifying forest landscape management. We discuss these lessons in the concluding parts of the paper.
Area and System of the Case Study
The mountain ash forests of the Central Highlands of Victoria, southeastern Australia cover ~140,000 ha and have been the focus of detailed ecological, silvicultural, economic and social science studies for more than four decades.
Mountain ash forests are spectacular and support the tallest flowering trees on Earth (approaching 100 m in height). These forests produce, capture and filter most of the water for the more than five million inhabitants of Melbourne, the second largest city in Australia. Mountain ash forests are important for biodiversity, including a range of threatened, endangered and critically endangered species.
These forests are important for Aboriginal people, such as the GunaiKurnai, Taungurung and Wurundjeri peoples. Old growth mountain ash forests store large amounts of carbon and are among the most carbon-dense forests in the world.
The ash-type forests of the Central Highlands of Victoria (which include mountain ash forests) currently support approximately 65 percent of all native forest logging in the state of Victoria, with the majority of timber going into the pulpwood and woodchip stream. Finally, the Central Highlands region in which mountain ash forests are located is also important for tourism.
The land tenure of mountain ash forests in the Central Highlands of Victoria consists largely of state forests (~92,000 ha) and national parks (~38,000 ha) (where logging is not permitted). Land management resides with Parks Victoria for national parks and the Department of Environment, Land, Water and Planning (DELWP) for state forests.
Approximately 60,000 ha of mountain ash forest from the state forests has been allocated to the Victorian government’s logging business, VicForests, for the purposes of logging for pulp logs and timber. DELWP is the land manager and service provider for state forests, where it supports the government in setting and determining policy.
Failure of the Regulated Forest to Produce Certainty in Sawlog Supply
The Victorian government’s vision of regulating the mountain ash forest has not produced a forest capable of sustaining a yield of wood products in perpetuity. Significantly, there has been a collapse of the capacity of the forest to provide logs to industry.
A major review into sawlog supply showed that previous modelling greatly overestimated the timber volume, with the implications for long-term logging capacity at the estimated rates of extraction for the Central Highlands of Victoria being ranked as weak to inadequate.
Even with subsequent sawlog yield reductions following that review, the legacy of historic overcutting remains in the forest, which is now interacting with a significant increase in wildfire frequency and extent.
Despite major wildfires, such as those in 2009 in which extensive areas of mountain ash forests were burned at high severity, there was limited appetite by the Government of Victoria to reduce the level of cut in mountain ash forests.
In its calculations of sustained yields of timber, VicForests failed to account for the inevitable losses in timber yields that would arise from wildfires. As a consequence of historic overcutting and subsequent wildfires, VicForests was forced to reduce its sawlog and pulp log supply commitments.
VicForests sought to attribute this reduction to new requirements requiring logging to exclude areas where the critically endangered Leadbeater’s possum was detected.
However, only 2,848 ha of mountain ash and alpine ash forest previously allocated and available to VicForests was excluded from logging as a result of Leadbeater’s possum detections. This equated to only 1.8 percent of the total area of ash forest allocated to VicForests.
Despite this, Leadbeater’s possum detections highlight the risks of the regulated forest approach in remaining small areas of unlogged and unburned forest where logging has conflicted with areas of high conservation value.
Proposed logging is scheduled across areas of highest priority for 70 threatened and forest-dependent species. In an increasingly disturbed forest estate, remaining least disturbed areas are becoming critically important for conservation.
Diversifying and Decentralising Landscape Management
A key outcome from the case study in mountain ash forests is that there has been a legacy of clinging to inappropriate and ultimately damaging historical policies such as the regulated forest concept implemented by centralised bureaucracies.
The mountain ash forests of the Central Highlands are now at significant risk of ecological collapse, as is the timber industry that is dependent on those forests.
Indeed, the mountain ash ecosystem has been formally classified as critically endangered under the IUCN red listed ecosystem process because of such risks of collapse.
The mountain ash forest estate is so extensively altered that options to diversify landscape management are limited. Ongoing logging, irrespective of the silvicultural system used, at the current rate or even a much-reduced rate, will now rapidly exhaust limited remaining timber supplies in mountain ash forests, add further to landscapes prone to high severity fire, drive down biodiversity and increase levels of forest fragmentation.
Adherence to clearly destructive ongoing policies will mean that logging operations will often have to target increasingly marginal areas such as forest on steep slopes.
Moreover, areas currently proposed for logging by VicForests under approved timber release plans overlap substantially with forests of high conservation value and will therefore have major negative impacts on threatened forest-dependent biodiversity.
The future prognosis for the timber industry is for yet further economic losses and ongoing declines in employment. Notably, the government of Victoria has made the decision to exit the native forest logging industry not only in mountain ash forests but also in native forests across the entire state by 2030, accessed on 28 February 2022).
Logging needs to be removed as an ecosystem stressor in mountain ash forests as part of concerted forest restoration efforts. For example, strengthened, long-term protection is needed to greatly expand the spatial extent of the old growth estate in mountain ash forests and thereby reduce forest flammability and recover key elements of biodiversity that are strongly associated with old growth forests such as the southern greater glider and the yellow-bellied glider (Petaurus australis).
A long-term objective should be to restore old growth forest cover to levels that historically characterised the ecosystem—between 30 and 60 percent of the estate or 30–60 times more than it is currently. However, given the current risk of high severity fire across an environment that is overwhelmingly dominated by young forest (with some areas therefore very likely be burned in the coming decades), far more than 30–60 percent of the mountain ash ecosystem will need to be protected to reach historical targets.
General Lessons for Forest Landscape Management from the Research
Our case study of mountain ash highlights how following inappropriate policies has led to a loss of options for diversifying forest management. The work has some important general implications for diversifying forest landscape management.
First, forest management strategies that are evidently ecologically sustainable must, by definition, account for uncertainty in resource availability such as those caused by disturbances.
In the case of mountain ash forests, changes in fire regimes linked with climate change, coupled with logging-related increases in forest fire severity, will have marked effects on log yields, but these problems have been largely overlooked by policy makers. Indeed, mountain ash forests have been managed with very little to no contingency for wildfire impacts on wood yields.
Another area of uncertainty is the impacts of new knowledge about biodiversity on resource availability. For example, long-term data have highlighted the marked temporal declines in populations of species of conservation concern such as Leadbeater’s possum and the southern greater glider.
This has, in turn, highlighted a need to exempt remaining areas of unlogged and unburned forest from logging to strengthen protection for these taxa, as recognised in a number of court cases successfully prosecuted against the Victorian government logging agency.
Second, well informed decisions about diversifying land management require a deep ecological, economic and social understanding of the target ecosystem. This understanding encompasses the condition of the forest ecosystem in question (e.g., the amount of old growth cover relative to historical levels), the status of biodiversity (including species of conservation concern), the integrity of key ecological processes (e.g., fire regimes), levels of timber resource availability and the impacts of logging on other values (e.g., water supply).
This understanding also needs to extend to knowledge of the potential for interactions between drivers of ecosystem integrity. For example, in mountain ash ecosystems, logging and fire interact, whereby harvested and then regenerated forests are at increased risk of burning at high severity. This, in turn, limits the chance of forests maturing, and reduces timber stocks and sawlog supplies.
Third, informed management that is ecologically sustainable needs to consider the combined impacts of all disturbance drivers, including those of a natural and human origin, in a given forest ecosystem.
In the case of mountain ash forests, the total disturbance burden in the ecosystem needs to be considered, particularly the effects of fire on timber resource availability. The Victoria government’s failure to do this and to reduce timber yields following extensive forest losses following major wildfires in 2009 led to the inevitable overcutting of remaining unburned forest.
This has both shortened the life of the native forest logging industry and foreclosed options to diversify landscape management strategies that could have maintained other forest values (e.g., the adoption of alternative silvicultural systems to clear-cutting such as the variable retention harvesting system).
Documents held by the government of Victoria indicate there were concerns about the rate of overcutting in the native forest logging industry as far back as the early 1990s. There also have been long-held concerns about widespread regeneration failure.
In fact, the government of Victoria reduced the levels of cut in their sustained yield calculations in all timber regions state-wide, except inexplicably, in large forest management units covering the mountain ash forests of the Central Highlands of Victoria. This highlights the importance of heeding early warning signals in levels of resource availability. Otherwise, future options for decision making can subsequently be foreclosed.
Fourth, decisions about forest landscape management need to be underpinned by truly independent assessments of wood resource availability. Such assessments should be made outside of government agencies and by experts and local working groups that do not have a strongly vested interest in resource industries.
In the case of the mountain ash forests, there is compelling evidence that the Victorian government failed to act as an independent arbiter of the status of wood stocks. Rather, government-based resource management agencies acted as an “arm of industry” and lobbied for long-term commitments of timber that locked in overcutting of the forest.
Finally, multifaceted data and perspectives are needed to help guide informed decision making about diversified landscape management. This can be realised through strategies of decentralisation becoming a critical component of the regime of forest management.
These include Aboriginal, ecological, economic, and social perspectives. In the case of the mountain ash ecosystem and plantations, these perspectives clearly indicate that: (1) There is very limited capacity to continue logging in the mountain ash forest; (2) Ongoing logging will have major negative impacts on biodiversity, water and fire regimes generating further economic losses; (3) There is currently sufficient plantation feedstock available to replace logs from mountain ash forests, particularly in the paper manufacturing sector; (4) The economic value of natural assets such as water, tourism and carbon far exceeds that of industrial logging in mountain ash forests; (5) There are major financial and environmental advantages to making a rapid transition from logging in mountain ash forests to plantation-based wood production.
Decentralised strategies for forest management could help Aboriginal communities assume greater control over their respective lands and determine modes of management specific to their respective areas. These can be aligned or contrasted with other needs of the community relevant to particular regions.