Motivated by environmental concerns, Australian governments are evaluating whether the native forestry industry can provide important ecological and economic solutions.
Dr Tyron Venn, Senior Lecturer in Agricultural and Natural Resource Economics at the University of Queensland, has reviewed the complexity of the production and conservation trade-offs in Queensland’s native forests in a recently published paper, “Reconciling timber harvesting, biodiversity conservation and carbon sequestration in Queensland, Australia.”
- A copy of the report is available for download here.
Dr Venn found that today’s decisions will set off a complex chain of benefits and costs for biodiversity and carbon emissions that will play out in Australia and internationally over decades.
“So, it’s important that well-informed decisions are made today,” Dr Venn said.
“The ecological and economic realities of the world suggest Queensland can maximise its contribution to reducing the climate crisis by continuing to manage its native forests for a mixture of timber production and conservation.Dr Tyron Venn – Senior Lecturer in Agriculture and Natural Resource Economics at the University of Queensland.
“A well-managed conservation estate is essential, especially to conserve species that require long-undisturbed forest habitat.
“Evaluations of Queensland’s conservation estate have expressed concern that these areas do not effectively conserve and recover many threatened species because of decades of low operational funding, which has prevented effective management of invasive weeds, feral animals and fire to create the diverse habitat mosaics required to conserve the full suite of flora and fauna in Queensland’s eucalypt forests.”
Dr Venn asserted that the published scientific literature suggests native forestry in Queensland helps to conserve biodiversity and mitigate climate risks.
Selection forestry can assist in creating mosaics of habitat at the landscape scale over time, leverage private sector resources to maintain important infrastructure such as fire breaks and maintain skills and capacity to manage prescribed fires and wildfires in difficult forest terrain.
Since the 1990s, Australia’s annual harvest of native hardwood sawlogs had dropped by 2.2 million cubic metres as large areas of state-owned native forests were declared national parks or other conservation reserves in which harvesting was not allowed.
At the same time, imports from Asia and the Pacific have increased by 1.9 million cubic metres a year.
According to Venn, China has been supplying most of these products, but they import their timber from Papua New Guinea, Solomon Islands, Cambodia, Myanmar, Laos, Indonesia, Malaysia, Thailand, the Congo, and Ghana.
In April, Wood Central reported that illegal and unsustainable harvesting can account for as much as 50% to 90% of timber produced in many tropical countries.
Therefore, since the 1990s, an ecological reality is that Australian consumers have been increasingly driving deforestation and forest degradation internationally, which threatens species such as the orangutan, Malayan tiger and the Asian sun bear.
“Reducing native forest hardwood production in Queensland will likely expand the state’s international ecological footprint,” says Dr Venn.
“Only selection harvesting is allowed in Queensland’s eucalypt forests, which typically removes 10 to 20 trees per hectare every 20 to 40 years.
“There are strict rules that regulate how the harvest operation is conducted and the condition of the forest following harvest, including minimum retention levels for trees of different sizes, such as large old trees with hollows.”
Dr Venn’s paper also shows the sustainability of this management regime was exemplified by the 1999 South East Queensland Forest Agreement, which immediately transferred 53% of the region’s publicly-owned timber production forests (state forests) to the conservation estate … because of the high conservation values that had been maintained over up to about 100 years of selection timber harvesting.
These transfers include the areas now known as D’Aguilar National Park, Lockyer National Park, Conondale National Park, Belthorpe National Park, Mapleton National Park, and Wrattens National Park.
“An ecological reality is that the major threats to Australia’s 1795 listed threatened species include invasive weeds (31.5% of threatened species), agriculture and aquaculture (22.9%), transportation and service corridors (18.0%), invasive predators (15.4%), urban development (13.5%), suppression in fire frequency or intensity (12.6%), and invasive ungulate (10%).”
“Forestry is the 25th most important threat to Australian biodiversity nationally, and forestry in Queensland threatens 0.8% of Australia’s threatened species. Given the scarce resources available to conserve biodiversity in Australia, it would be useful to investigate the cost-effectiveness of increased biodiversity conservation efforts directed at the 24 more important threats to biodiversity.”
“The vast majority of Queensland eucalypt forest flora and fauna are well-adapted to periodic disturbances by selection harvesting.”
“For example, most of Queensland’s threatened species are plants, many of which are threatened by a lack of disturbance. Forestry practices, including thinning, prescribed fire and harvesting, have been recommended to improve the habitat for these species in fire-excluded eucalypt forests.”
“The six key threats to Queensland’s koala population are well-known and do not include forestry. Indeed, koalas are known to be highly resilient to selection forestry.”
- A copy of the original 1999 South East Queensland Forest Agreement is available for download here.
Existing native forestry codes of practice require the retention of habitat trees at levels recommended by scientists to conserve the yellow-bellied glider and greater glider.
- A copy of the Code of Practice for Native Forest Timber Production on Queensland State Forests can be downloaded here.
Dr Venn says Queensland should continue to manage some of its native forests for wood products for the carbon benefits, as recommended by the Intergovernmental Panel on Climate Change (IPCC).
The IPCC has long argued that managing forests to produce an annual sustained yield of timber, fibre, and energy will generate the largest sustained carbon sequestration benefit from forests.
“This is because of the economic reality that Australians do not reduce their consumption of products when our native forests are no longer selectively harvested for high-value products, such as electricity distribution poles, decking, flooring and structural timbers,” Dr Venn said.
“We simply substitute with different products that have high carbon emissions associated with them, such as steel, aluminium, concrete, brick, plastic and carpet, as well as imported timbers from Asia where forest carbon stocks may be permanently lost because of poor forest harvesting practices and land clearing following harvest.”
He says increasing Queensland’s plantation forest area should be part of the state’s strategy to supply sustainable products to consumers.
“However, the national estate area has decreased by more than 12% since 2012 because of poor financial returns.”
“Attempts in Queensland to establish hardwood plantations since 2000 have been unsuccessful and are projected to produce about 4% of the log volume presently harvested from the state’s native forests.”
“Any new plantation forests that might be established today to replace production from native forests will require displacement of agriculture, a substantial and long-term reallocation of scarce government funding and will take decades to produce timber.”
Meanwhile, Australia’s population continues to grow rapidly and needs structural products today.
“Queensland can maximise the contribution of its native forests to addressing the global climate crises by continuing to manage some areas for timber production.”
“If Queensland reduced its native forestry in the near future, it would likely result in increased timber imports and use of carbon-polluting substitutes for at least 30 years.’Dr Tyron Venn – Senior Lecturer in Agriculture and Natural Resource Economics at the University of Queensland.