Papua New Guinea Rainforests Being Destroyed


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Australia is a global top-ten deforester – and Queensland is leading the way


Noel D Preece, James Cook University and Penny van Oosterzee, James Cook University

When you think of devastating deforestation and extinction you usually think of the Amazon, Borneo and the Congo. But eastern Australia ranks alongside these in the top 10 of the world’s major deforestation fronts – the only one in a developed nation. Most of the clearing is happening in Queensland, and it is accelerating.

Only last year a group of leading ecologists voiced their alarm at new data which showed the clearing of 296,000 hectares of forest in 2013-14. This was three times higher than in 2008-09, kicking Australia up the list as one of the world’s forest-clearing pariahs. At the 2016 Society for Conservation Biology Conference, a Scientists’ Declaration was signed by hundreds of scientists, expressing concern at these clearing rates.


Read more: Queensland land clearing is undermining Australia’s environmental progress


But the latest snapshot, Queensland’s Department of Science report on land cover change published last month, showed a staggering 395,000ha of clearing for 2015-16: an increase of one third on 2014-15. As far as we can tell this rate of increased clearing is unmatched anywhere else on the globe.

showed a staggering 395,000 of clearing for 2015-16: which is an increase of one third on 2014-15, or 133% over the period

Strong vegetation management laws enacted in Queensland – the Vegetation Management Act 1999 – achieved dramatic reductions in forest and woodland loss. But the subsequent Liberal National state government, elected in 2012, overturned these protections.

The current government, elected in 2015, has tried and failed to reinstate the protections. In response, “panic clearing” caused clearing rates to shoot up, in anticipation that the state election will deliver a government that will reintroduce the much-needed protection of forests.

The Queensland Parliament is now in caretaker mode ahead of the November 25 election. The Queensland Labor Party has pledged to reinstate laws to prevent wholesale clearing, while the LNP opposition has vowed to retain current clearing rates.

Forest cleared by bulldozers towing massive chains.
Noel Preece

Australian community and wildlife lose

Whichever way you look at it, there is not a lot of sense in continued clearing. Australia already has some of the highest extinction rates on the planet for plants and animals. With 80% of Queensland’s threatened species living in forest and woodland, more clearing will certainly increase that rate.

Clearing also kills tens of millions of animals across Australia each year, a major animal welfare concern that rarely receives attention. This jeopardises both wildlife and the A$140 million invested in threatened species recovery.


Read more: Land clearing isn’t just about trees – it’s an animal welfare issue too


This rate of clearing neutralises our major environment programs. Just one year of clearing has removed more trees than the bulk of 20 million trees painstakingly planted, at a cost of A$50 million. Australia’s major environment programs simply can’t keep up, and since 2013 are restoring only one-tenth of the extent of land bulldozed just last year.

Restoration costs to improve the quality of waters running onto the Great Barrier Reef are estimated at around A$5 billion to A$10 billion over 10 years. Nearly 40% of the land cleared in Queensland is in reef catchments, which will reverse any water quality gains as sediment pours onto the reef.

Climate efforts nullified

Since 2014, the federal government has invested A$2.55 billion on reducing emissions in the Carbon Farming Initiative through the Emissions Reduction Fund. Currently 189 million tonnes of abatement has been delivered by the Emissions Reduction Fund. This – the central plank of the Australian government’s climate response – will be all but nullified by the end of 2018 with the current clearing rates, and will certainly be wiped out by 2020, when Australia is expected to meet its climate target of 5% below 2000 emissions.

Ironically, this target will be achieved with the help of carried-over results from the first commitment period of the Kyoto Protocol, which Australia was only able to meet because land clearing had decreased between 1990 and 1997.

Why is this happening?

Most of the clearing in Queensland since 1999 has been for pasture. Most good cropping land was cleared decades ago. Removing trees in more marginal lands can increase the carrying capacity for a short time with an immediate, and usually short-lived, financial reward. These rewards come at the expense of long-term sustainability, which future landholders and government will bear.

Large areas of the cleared lands have been subject to substantial erosion and nutrient loss from the newly cleared lands, and land degradation over time, and some areas have suffered massive woody weed incursions.

This is playing out today across the north where pastoralism is a marginal activity at best, with declining terms of trade of about 2% per year, with no net productivity growth, high average debts and low returns, and many enterprises facing insolvency. Clearing vegetation won’t change that.

A recent preliminary valuation of ecosystem services, on the other hand, estimated that uncleared lands are worth A$3,300-$6,100 per hectare per year to the Australian community, compared with productivity of grazing lands of A$18 per hectare.

With a clear divide between the policies Labor and the LNP are taking to the election, now is a good time to give land clearing’s social, economic and environmental impact the scrutiny it deserves.


The ConversationThis article was updated on November 21 to reflect that land clearing increased in by a third in 2015-16 over 2014-15 levels. Previously the article stated an increase of 133%.

Noel D Preece, Adjunct Principal Research Fellow at Charles Darwin and, James Cook University and Penny van Oosterzee, Principal Research Adjunct James Cook University and University Fellow Charles Darwin University, James Cook University

This article was originally published on The Conversation. Read the original article.

Land clearing isn’t just about trees – it’s an animal welfare issue too



File 20170704 10704 10o5p14
This quenda seems to have been a victim of land clearing.
Colin Leonhardt/Birdseyeviewphotography.com.au, Author provided

Hugh Finn, Curtin University

Tens of millions of wild animals are killed each year by land clearing across Australia, according to our research on the harm done to animals when native vegetation is removed for agricultural, urban and industrial development.

As my colleague Nahiid Stephens and I point out in our study, this harm to animals is largely invisible, unlike the obvious effects of clearing on trees and other plants. But just because something is invisible, that does not mean it should be ignored.

We argue that reforms are necessary to ensure that decision-makers take wild animals’ welfare into account when assessing development proposals and land clearing applications.

How does land clearing harm animals?

Land clearing harms animals in two basic ways. First, they may be killed or injured when native vegetation is removed, typically through the use of earth-moving machinery. For example, animals may suffer traumatic injuries or be smothered when vegetation is cut or soil and debris are shifted.

Second, the removal of native vegetation puts animals in harm’s way. Those that survive the clearing process will be left in an environment that is typically hostile, unfamiliar or unsuitable. Animals are likely to find themselves in landscapes that are devoid of food and shelter but filled with predators, disease, and increased aggression from members of their own species as they struggle to make a living.

Land clearing causes animals to die in ways that are physically painful and psychologically distressing. Animals will also suffer physical injuries and other pathological conditions that may persist for days or months as they try to survive in cleared areas or other environments to which they are displaced.

Many reptiles and mammals are territorial or have small home ranges, and thus have strong associations with small areas of habitat. Koalas in urban areas, for example, tend to rely on particular food trees. Likewise, lizards and snakes often rely on particular microhabitat features such as logs, rocks, and leaf litter to provide the combination of temperature and humidity that they need to survive.

Laws are not protecting animals

Land clearing remains a fundamental pressure on the Australian environment. While the regulatory frameworks for land clearing vary greatly across the Australian states and territories, the principal statutes that govern native vegetation clearance in most jurisdictions typically contain some sort of express recognition of the harm that land clearing causes, such as the loss or fragmentation of habitat, land degradation, and salinity.

Habitat lost: land cleared for the now-discontinued Perth Freight Link road project.
Colin Leonhardt/Birdseyeviewphotography.com.au, Author provided

Yet these regulations are uniformly silent on the issue of how land clearing harms animals. No state or territory has developed a clear framework to evaluate this harm, let alone minimise it in future development proposals.

This failure to recognise animal welfare as a significant issue for decision-making about land clearing is troubling, especially given the scale of current land clearing. In Queensland, for example, an estimated 296,000 hectares of woody vegetation was cleared in 2014-15, nearly all of which was for the purpose of converting native vegetation to pasture. In our study we estimate that, on the basis of previous studies and current estimates of clearing rates, land clearing in Queensland and New South Wales combined kills more than 50 million birds, mammals and reptiles each year.

What reforms are necessary?

We suggest that two basic reforms are required. First, state and territory parliaments should amend the laws that govern environmental impact assessments and native vegetation clearance, to require decision-makers to take animal welfare into account when assessing land clearing applications.

Second, we urgently need accurate ways to evaluate the harm that proposed clearing actions may cause to individual animals. Animal welfare is broadly recognised as an important social concern, so it makes sense that in a situation where we know animals are being harmed, we should take steps to measure and prevent that harm.

The basic aim of any reform should be to ensure that the harm that land clearing causes to individual wild animals is appropriately considered in all forms of environmental decision-making and that such evaluations are based on clear and objective criteria for animal welfare.

At a minimum, those who apply to clear native vegetation should be required to provide an estimate of the number and type of native animals that will be killed by the proposed land clearing. This would ensure that all parties – applicants, decision-makers, and the community – understand the harm that the clearing would cause. These estimates could be made by using population density information for species that are likely to be affected – an approach that has been already been used.

We also need to revise our perceptions about the usefulness and necessity of land clearing in Australia. A better idea of what is “acceptable” would include not only the environmental costs of clearing an area of native vegetation, but also the individual suffering that animals will experience.

Issues of causation and responsibility are critical here. While it’s unlikely that someone who wants to clear land actually wants native animals to suffer, such suffering will nevertheless be an inevitable consequence. The relevant question is not whether animals will be killed and harmed when land is cleared, but how much of that harm will occur, how severe it will be, and whether it ought to be avoided.

The ConversationIf such harm is deemed necessary – based on an accepted system for weighing the potential benefits and harms – the next question is how the harm to animals can be minimised by, for example, keeping the amount of vegetation to be cleared to a minimum.

Hugh Finn, Lecturer, Curtin University

This article was originally published on The Conversation. Read the original article.

Land clearing on the rise as legal ‘thinning’ proves far from clear-cut


File 20170619 770 h5c4tb
A ‘thinned’ landscape, which provides far from ideal habitat for many species.
Author provided

April Reside, The University of Queensland; Anita J Cosgrove, The University of Queensland; Jennifer Silcock, The University of Queensland; Leonie Seabrook, The University of Queensland, and Megan C Evans, The University of Queensland

Land clearing is accelerating across eastern Australia, despite our new research providing a clear warning of its impacts on the Great Barrier Reef, regional and global climate, and threatened native wildlife.

Policies in place to control land clearing have been wound back across all Australian states, with major consequences for our natural environment.

One of the recent policy changes made in Queensland and New South Wales has been the introduction of self-assessable codes that allow landholders to clear native vegetation without a permit. These codes are meant to allow small amounts of “low-risk” clearing, so that landholders save time and money and government can focus on regulating activities that have bigger potential impacts on the environment.

However, substantial areas of native forest are set to be cleared in Queensland under the guise of vegetation “thinning”, which is allowed by these self-assessable codes. How did this happen?

Thin on the ground

Thinning involves the selective removal of native trees and shrubs, and is widely used in the grazing industry to improve pasture quality. It has been argued that thinning returns the environment back to its “natural state” and provides better habitat for native wildlife. However, the science supporting this practice is not as clear-cut as it seems.

Vegetation “thickening” is part of a natural, dynamic ecological cycle. Australia’s climate is highly variable, so vegetation tends to grow more in wetter years and then dies off during drought years. These natural cycles of thickening and thinning can span 50 years or more. In most areas of inland eastern Australia, there is little evidence for ongoing vegetation thickening since pastoral settlement.

Thinning of vegetation using tractors, blades and other machinery interrupts this natural cycle, which can make post-drought recovery of native vegetation more difficult. Loss of tree and shrub cover puts native wildlife at much greater risk from introduced predators like cats, and aggressive, “despotic” native birds. Thinning reduces the diversity of wildlife by favouring a few highly dominant species that prefer open vegetation, and reduces the availability of old trees with hollows.

Many native birds and animals can only survive in vegetation that hasn’t been cleared for at least 30 years. So although vegetation of course grows back after clearing, for native wildlife it’s a matter of quality, not just quantity.

Land clearing by stealth?

Thinning codes in Queensland and New South Wales allow landholders to clear vegetation that has thickened beyond its “natural state”. Yet there is little agreement on what the “natural state” is for many native vegetation communities.

Under the Queensland codes, up to 75% of vegetation in an area can be removed without a permit, and in New South Wales thinning can reduce tree density to a level that is too low to support natural ecosystems.

All of this thinning adds up. Since August 2016, the Queensland government has received self-assessable vegetation clearing code notifications totalling more than 260,000 hectares. These areas include habitat for threatened species, and ecosystems that have already been extensively cleared.

It may be that the actual amount of vegetation cleared under thinning codes is less than the notifications suggest. But we will only know for sure when the next report on land clearing is released, and by then it will be too late.

Getting the balance right

Vegetation policy needs to strike a balance between protecting the environment and enabling landholders to manage their businesses efficiently and sustainably. While self-regulation makes sense for some small-scale activities, the current thinning codes allow large areas of vegetation to be removed from high-risk areas without government oversight.

Thinning codes should only allow vegetation to be cleared in areas that are not mapped as habitat for threatened species or ecosystems, and not to an extent where only scattered trees are left standing in a landscape. Stronger regulation is still needed to reduce the rate of land clearing, which in Queensland is now the highest in a decade.

Protecting native vegetation on private land reduces soil erosion and soil salinity, improves water quality, regulates climate, and allows Australia’s unique plants and animals to survive. Landholders who preserve native vegetation alongside farming provide essential services to the Australian community, and should be rewarded. We need long-term incentives to allow landholders to profit from protecting vegetation instead of clearing it.

Our research has shown that Australian governments spend billions of dollars trying to achieve the benefits already provided by native vegetation, through programs such as the Emissions Reduction Fund, the 20 Million Trees program and Reef Rescue. Yet far more damage is inflicted by under-regulated clearing than is “fixed” by these programs.

The ConversationImagine what could be achieved if we spent that money more effectively.

April Reside, Researcher, Centre for Biodiversity and Conservation Science, The University of Queensland; Anita J Cosgrove, Research Assistant in the Centre for Biodiversity and Conservation Science, The University of Queensland; Jennifer Silcock, Post-doctoral research fellow, The University of Queensland; Leonie Seabrook, Landscape Ecologist, The University of Queensland, and Megan C Evans, Postdoctoral Research Fellow, Environmental Policy, The University of Queensland

This article was originally published on The Conversation. Read the original article.

Stopping land clearing and replanting trees could help keep Australia cool in a warmer future


Clive McAlpine, The University of Queensland; Jozef Syktus, The University of Queensland, and Leonie Seabrook, The University of Queensland

Land clearing is on the rise in Queensland and New South Wales, with land clearing laws being fiercely debated.

In Queensland in 2013–14, 278,000 hectares of native vegetation were cleared (1.2 times the size of the Australian Capital Territory). A further 296,000ha were cleared in 2014–15. These are the highest rates of deforestation in the developed world.

Land clearing on this scale is bad for a whole host of reasons. But our research shows that it is also likely to make parts of Australia warmer and drier, adding to the effects of climate change.

How do trees change the climate?

Land clearing releases greenhouse gases into the atmosphere, but the effect of land clearing on climate goes well beyond carbon emissions. It causes warming locally, regionally and even globally, and it changes rainfall by altering the circulation of heat and moisture.

Trees evaporate more water than any other vegetation type – up to 10 times more than crops and pastures. This is because trees have root systems that can access moisture deep within the soil. Crops and pastures have 70% of their roots in the top 30cm of the soil, while trees and other woody plants have 43% of their roots in the deeper part of the soil.

The increased evaporation and rough surface of trees creates moist, turbulent layers in the lower atmosphere. This reduces temperatures and contributes to cloud formation and increased rainfall. The increased rainfall then provides more moisture to soils and vegetation.

The clearing of deep-rooted native vegetation for shallow-rooted crops and pastures diminishes this process, resulting in a warmer and drier climate.

We can see this process at work along the “bunny fence” in southwest Western Australia, where there is a moister atmosphere and more clouds over native vegetation compared with nearby farming areas during summer.

Studies in Amazonia also indicate that as deforestation expands rainfall declines. A tipping point may be reached when deforestation reaches 30-50%, after which rainfall is substantially reduced. Complete deforestation results in the greatest decline in rainfall.

More trees, cooler moister climate

We wanted to know how land clearing could affect Australia’s climate in the future. We did this by modelling two scenarios for different amounts of land clearing, using models developed by CSIRO.

In the first scenario, crops and pasture expand in the semi-arid regions of eastern and southwest Australia. The second scenario limits crops and pastures to highly productive lands, and partially restores less productive lands to savanna woodlands.

We found that restoring trees to parts of Australia would reduce surface temperatures by up to 1.6℃, especially in western Queensland and NSW.

We also found that more trees reduced the overall climate-induced warming from 4.1℃ to 3.2℃ between 2050 and 2100.

Replanting trees could increase summer rainfall by 10% overall and by up to 15.2% in the southwest. We found soil moisture would increase by around 20% in replanted regions.

Our study doesn’t mean replanting all farmed land with trees, just areas that are less productive and less cost-effective to farm intensively. In our scenario, the areas that are restored in western Queensland and NSW would need a tree density of around 40%, which would allow a grassy understorey to be maintained. This would allow some production to continue such as cattle grazing at lower numbers or carbon farming.

Political and social challenges

Limiting land clearing represents a major challenge for Australia’s policymakers and farming communities.

The growing pressure to clear reflects a narrow economic focus on achieving short- to medium-term returns by expanding agriculture to meet the growing global demand for food and fibre.

However, temperatures are already increasing and rainfall is decreasing over large areas of eastern and southwest Australia. Tree clearing coupled with climate change will make growing crops and raising livestock even harder.

Balancing farming with managing climate change would give land owners on marginal land new options for income generation, while the most efficient agricultural land would remain in production. This would need a combination of regulation and long-term financial incentives.

The climate benefits of limiting land clearing must play a bigger part in land management as Australia’s climate becomes hotter and drier. Remnant vegetation needs to be conserved and extensive areas of regrowth must be allowed to regenerate. And where regeneration is not possible, we’ll have to plant large numbers of trees.

The Conversation

Clive McAlpine, Professor, The University of Queensland; Jozef Syktus, Principal Research Fellow, Global Change Institute, The University of Queensland, and Leonie Seabrook, Landscape Ecologist, The University of Queensland

This article was originally published on The Conversation. Read the original article.

Queensland moves to control land clearing: other states need to follow


Megan C Evans, Australian National University

Queensland’s land clearing has yet again become a national issue. After laws were relaxed under the then Liberal-National state government in 2013, land-clearing rates tripled, undermining efforts to conserve wildlife and reduce carbon emissions.

Now the Labor state government wants to re-tighten the laws. The revised legislation is expected to be debated after June 30.

Land clearing is a highly contentious and polarising issue in Queensland. Scientists and environmental groups have voiced concerns about the dramatic increase in land clearing. But some rural landholders are reportedly worried about the prospect of re-tightened regulations and their possible impact on property values and business certainty.

So, what does the big picture suggest?

Then and now

Since the 1980s, all Australian states and territories have introduced laws to protect native vegetation, in response to rising public concern about land degradation, salinity, biodiversity loss and greenhouse gas emissions.

The most significant policy reforms have been in Queensland – where the vast majority of land clearing in Australia has occurred over the past four decades – as I show in a new paper published in Pacific Conservation Biology.

Total forest loss due to human activity from 1972 – 2014. Data is sourced from the National Carbon Accounting System (NCAS), Australian Department of the Environment (2015). Image: Evans (2016) http://dx.doi.org/10.1071/PC15052

Changes to land-clearing laws in 2007 were heralded as the end of broad-scale clearing in Queensland. Clearing of remnant (old-growth) forest was restricted on freehold land, all remaining clearing permits (issued under a ballot) expired and A$150 million of compensation was provided to landholders. Further amendments in 2009 placed protections on “high value” (more than 20 years old) regrowth forest.

Fast forward to 2012, and Premier Campbell Newman was elected on a promise to keep Queensland’s land clearing laws in place. Soon afterwards though, Natural Resources Minister Andrew Cripps announced the Government would “take an axe” to tree-clearing laws.*

The 2013 amendments:

  • removed protections on “high value” regrowth forest

  • allowed landholders to self-assess clearing for activities such as fodder harvesting and vegetation thinning

  • allowed clearing of remnant forest for “high-value agriculture”

  • changed the onus of proof so that the Queensland government had to prove that land-clearing laws had been violated.

Queensland’s current Labor government intends to reverse most of the 2013 amendments to vegetation-clearing laws, as well as extending protections on regrowth forest to three additional catchments, to reduce runoff onto the Great Barrier Reef.

The laws will also be retrospective, in an effort to prevent panic clearing before the changes come in.

How does Queensland compare?

Queensland is not alone in its recent changes to vegetation protection laws.

New South Wales introduced self-assessment for “low risk” clearing in 2013. It also promised to repeal the Native Vegetation Act and replace it with a new Biodiversity Conservation Act. An independent review recommended that these changes occur, but environmental groups remain opposed.

Victoria’s vegetation laws were also changed in 2013. The then Coalition government’s changes included the removal of the “net gain” target in vegetation extent and quality that had been in place since 2003. The Victorian Labor government is now undertaking another review of the state’s regulations.

Laws have also been relaxed in Western Australia, where landholders may now clear up to 5 hectares per year on individual properties without a permit (an increase from 1 ha per year).

From state to self-regulation

Within ten years of what looked like the end of broad-scale land clearing in Australia, most state vegetation laws across the country have been relaxed.

Government regulation of native vegetation is generally unpopular with landholders and so maintaining these policies has proven to be politically unpalatable. At this stage, only Queensland is looking to re-strengthen land-clearing laws – and, even so, self-assessment for some clearing activities will remain.

What does this all mean for native vegetation in Australia? This is actually a difficult question to answer.

Many factors influence land clearing: rainfall, the price of key agricultural commodities and the amount of land available to clear. This complexity means it’s difficult to know what impact (if any) changes in policy have on the rate of land clearing.

Trends in national-scale deforestation and key macroeconomic variables. Plots are total deforestation versus: a) Year, b) Extent of primary forest remaining, c) Log-transformed total rainfall, d) Gross domestic product per capita (current USD) , e) Agriculture, value added (% total GDP) f) Farmer’s terms of trade. Image: Evans (2016) http://dx.doi.org/10.1071/PC15052

It’s quite clear that the relaxation of Queensland’s clearing laws was followed by a sharp increase in vegetation clearing, but it’s not yet apparent whether this has happened in other states.

A big issue is a lack of reliable data. There’s no consistent reporting of vegetation clearing across Australia. Some states, such as New South Wales, only publish information on the amount of clearing permitted by regulation.

As reported last week, total vegetation clearing in New South Wale is much higher than official data shows as most clearing is exempt from regulation, or illegal.

Better policy needed

If we’re serious about protecting Australia’s native vegetation for the sake of soil health, biodiversity and the climate, we need to use all the tools we have available to achieve this goal.

Using a mixture of government regulation, self-regulation and genuine economic incentives, such as carbon farming, is the best approach.

But no matter which policies we use, they all need to be monitored and evaluated to be effective. Otherwise, we have no idea whether all the time and money devoted to designing and implementing new policies has been worthwhile.

The inconsistency between the federal government’s Direct Action policy and the relaxation of state restrictions on vegetation clearing is a big problem. Landholders need a clear and consistent message from all levels of government if they are to adapt and make long-term business decisions.

Interestingly, around 75% of the recent clearing in Queensland has occurred in the Brigalow Belt and Mulga – areas where we’ve found that carbon farming could be more profitable than cattle grazing.

If only the price, and the policies, were right.

*This sentence was amended on May 10 2016 to clarify that land clearing laws were originally to be maintained.

The Conversation

Megan C Evans, PhD Candidate in Environmental Policy, Australian National University

This article was originally published on The Conversation. Read the original article.

EcoCheck: can the Brigalow Belt bounce back?


Leonie Seabrook, The University of Queensland; Clive McAlpine, The University of Queensland, and Martine Maron, The University of Queensland

Our EcoCheck series takes the pulse of some of Australia’s most important ecosystems to find out if they’re in good health or on the wane.

Queensland’s Brigalow Belt is among Australia’s most significant biodiversity hotspots. Extending over an area of 36.4 million hectares from Townsville down into New South Wales, it was famously where the explorer Ludwig Leichhardt travelled, prickly pear was vanquished, and the now-extinct paradise parrot once lived.

The Brigalow Belt bioregions.
Hesperian/IBRA/Wikimedia Commons

Although the region contains diverse ecosystems, from dry vine scrub to grasslands, it is named after the species of tree that once dominated: the brigalow (Acacia harpophylla). This unusual, long-lived acacia with its dark, fissured bark and distinctive silver leaves forms dense woodlands, home to unique and threatened plants and animals.

Before clearing, brigalow-dominated ecological communities covered an estimated 7.5 million ha within the Brigalow bioregion. But those vast brigalow woodlands are no longer here.

Remnant brigalow woodland, Queensland.

Sought-after soil

Since the arrival of Europeans in the 1850s, 90% of brigalow forest has been cleared. Brigalow grows on fertile, cracking clay soils – the same soils needed for agriculture. Only 790,000 ha of brigalow ecosystems remain – just over 10% of the original extent. Sixteen out of 22 ecosystems where brigalow is the dominant or co-dominant species have less than 10% left – and even those are under threat.

Clearing of brigalow for crops and pasture began soon after European settlement. Initially, the task of turning the Brigalow into a breadbasket turned out to be more challenging than the settlers expected. Brigalow trees have a well-developed lateral root system. If the tree or roots are damaged, dense “suckers” spring up. This growth stage can last for 20-30 years and is followed by a “whipstick” stage lasting another 20-30 years before mature forest is formed.

This habit made permanent removal very difficult, as suckers can occur at a density of 20,000 stems per hectare.

Very young brigalow regrowth.

Agricultural development was also delayed by the invasion by prickly pear. Between 1901 and 1925, these spiky American cacti spread across 24 million ha of Queensland and NSW. Communities and governments despaired of being able to control this weed, but by 1932 a biological control agent, the Cactoblastis moth, had almost completely destroyed prickly pear.

It was not until the 1960s – and a “perfect storm” of mechanised land clearing, favourable government policies, scientific research into brigalow control, and a push for agricultural development – that clearing could occur on a grand scale. Once the problem was cracked, clearing rates soared. At times, rates equalled those in tropical forest regions such as the Amazon and Southeast Asia.

Legacy of loss

Today, the Brigalow Belt is a precious, but threatened, reservoir of endemic diversity. Brigalow woodland is nationally endangered, with severe consequences for the animals of the Brigalow Belt. Four species, including the paradise parrot, are extinct. Another 17 are on the threatened species list in either NSW or Queensland.

The Brigalow Belt is home to the threatened golden-tailed gecko.
Dave Fleming/Atlas of Living Australia

Remaining patches of brigalow are often modified by the removal of understorey shrubs and fallen timber. This affects habitat structure for reptiles and woodland birds in particular, reducing population sizes and encouraging aggressive competitors such as the noisy miner.

Many exotic species have been introduced, including pasture grasses. The most widespread of these is buffel grass, which has been a boon for pastoralists. Unfortunately, its invasion of remnant brigalow and contribution to fuelling bushfires has had dramatic effects on plant and animal biodiversity.

The Brigalow Belt is also home to 13 reptile species that are found only in this region, and another 14 for which the region is their main home. Eleven of the 148 reptile species found in the Brigalow Belt are threatened.

But the very suckering habit that made brigalow trees so difficult to clear in the early days may now be its salvation. Although brigalow regrowth is initially very different from old-growth woodland, if it is allowed to persist, the vegetation structure becomes more and more complex and diverse. After 30-50 years, mature regrowth can support as many bird species as old-growth woodland.

The future of the brigalow

Only 1% of the remaining brigalow woodland is in protected areas. The rest is highly fragmented, existing mainly as tiny patches, linear strips along roads and fence lines, and areas of regrowth.

Land-use change for agriculture, coal mining and coal seam gas extraction continues to nibble away at remaining brigalow ecosystems, despite protection by state and federal laws. In 2013-14, 44% of all woody vegetation clearing in Queensland occurred in the Brigalow Belt.

Legislation controlling most broadscale clearing of remnant native vegetation was introduced through the Queensland Vegetation Management Act 1999. This phased out clearing of remnant vegetation by December 2006. In 2008, recognising that the only way to recover threatened ecosystems like brigalow forest was to increase their extent, mature “high-value” regrowth of threatened ecosystems was also protected.

But in 2013 came a setback, with the introduction of the Vegetation Management Framework Amendment Act 2013, which allowed for much more vegetation clearing and removed the protections for high-value regrowth. Laws to reinstate those protections are before the Queensland Parliament.

The opportunity to recover the brigalow will not last forever. With repeated clearing, burning and cultivation, these forests could eventually disappear for good. But in those areas where some resilient regrowth remains, there is potential for recovery.

In 2009, there was an estimated 7,226 square km of regrowth, comprising a range of structures from juvenile bushes (aged 5-10 years) to almost mature stands (aged 30-50 years). This regrowth provides a promising and cost-effective way to increase habitat area for both fauna and flora, and reduce their risk of extinction.

To do this, however, we need to find ways to make retention of brigalow regrowth attractive and valuable to landholders, through stewardship schemes or carbon offsets. Only then might the Brigalow Belt bounce back.

Are you a researcher who studies an iconic Australian ecosystem and would like to give it an EcoCheck? Get in touch.

The Conversation

Leonie Seabrook, Landscape Ecologist, The University of Queensland; Clive McAlpine, Senior Research Fellow in Ecology, The University of Queensland, and Martine Maron, ARC Future Fellow and Associate Professor of Environmental Management, The University of Queensland

This article was originally published on The Conversation. Read the original article.