Dr Oisín Sweeney, Senior Ecologist, National Parks Association of NSW
A case study on the Victorian Central Highlands
Back in June, scientists and economists from the Australian National University produced a ground-breaking piece of work. They published a set of experimental ‘ecosystem accounts’ for the Central Highlands region of Victoria. NPA Senior Ecologist, Dr Oisín Sweeney, explains the relevance of this approach.
What are ecosystem accounts and why are they useful?
In essence, ecosystem accounts attempt to put a value on elements of an ecosystem that are typically overlooked in decision making. The thinking is that by developing accounts, decision makers can make more informed land-use decisions by having a full suite of information. Currently, decisions on land use are made with only partial information—a situation that would never be countenanced in most business decisions! In this instance the researchers looked at three elements:
- Ecosystem services including water supply, carbon storage, timber provision, provisioning for crops and fodder production and culture and recreation;
- The contribution to GDP by industries including agriculture, water supply, tourism and logging; and,
- Metrics relevant to biodiversity including populations of arboreal marsupials, the number of threatened species, forest age-class and number of tree hollows.
Why the Victorian Central Highlands?
The Central Highlands are a very special part of the state of Victoria. Their forested catchments supply water to Melbourne’s four million people and are home to the tallest flowering plants in the world, the Mountain Ash (Eucalyptus regnans). In an undisturbed state, these are the most carbon-dense forests on earth storing up to 1,867 tonnes of carbon per hectare1 but the forests are logged under a Regional Forest Agreement (RFA), due to expire in 2017. There is a major new national park being proposed for the region: The Great Forest National Park is based largely around the urgent need to protect the critically endangered Leadbeater’s Possum (Gymnobelideus leadbeateri), but is also needed to avoid collapse of the entire ecosystem due to logging and fire. Under business as usual collapse will occur by 20652. Currently, under the RFA, timber is the only product afforded any value. These ecosystem accounts change that!
So what did they find?
1. Ecosystem services
In 2014 two ecosystem services—provisioning of crops and fodder and water provision—dwarfed other services being worth approximately $120 million and $100 million respectively. Culture and recreation were worth approximately $45 million, timber provisioning (the value of timber minus haulage and harvest costs) $25 million and carbon sequestration $20 million.
But when GDP was considered things got really interesting: water and agriculture were again the most valuable at $2,319 and $2,477 per hectare (ha) respectively. Tourism was worth $354/ha (a conservative estimate because the entire study area was used in the calculation, whereas in reality tourism is likely to be focussed in a smaller area than the total).
Timber was worth just $29/ha. But logging also had a major negative impact on carbon sequestration and carbon stocks: logging reduced sequestration by 3.13 tonnes of carbon per hectare year between 1990 and 2015 – equivalent to $37.87 per hectare per year at a carbon price of $12.10 per tonne3. Furthermore, logging reduced the carbon stocks of forests by 143 tonnes/ha. At $12.10 per tonne this lost carbon is worth $1,730/ha – or 60 times the value of the timber.
So the double impact of logging on carbon sequestration and storage means that logging costs much more than it makes.
The key findings relevant to biodiversity were:
- Since 2000, the number of threatened species had risen from 28 to 38, with the number of critically endangered species rising from 0 to 5;
- The proportion of forests in older age classes had declined and logging reduced the number of hollow-bearing trees by 70% (compared to 42% loss from fire);
- Populations of arboreal marsupials had fallen sharply in all forest age classes, but old-growth had more species and higher numbers of animals;
- Logging on rotations less than 120 years will result in no recruitment of hollow-bearing trees due to the time needed for hollows to form;
- The key threatening process to arboreal mammals was the loss of hollow-bearing trees and lack of recruitment of older trees.
One concern that people have with environmental accounts is that they fear nature will be given a price tag, and that the price of conserving nature will inevitably be higher than development. In this case the authors didn’t attempt to place a monetary value on wildlife, yet their findings on biodiversity are still stark.
What are the implications for NSW?
Governments at both a state and federal level are loathe to face up to the realities, economic and environmental, of native forest logging. Part of this is inertia—it’s easier not to change something that’s been occurring for a long time. But partly it’s because the economic value of forests has only ever been measured as the value of timber (or woodchips) that they can produce.
Forest ecosystem accounts offer the Baird government—which will soon make decisions on logging—a mechanism to more honestly appraise whether logging is a good idea, and to move beyond the industry spin of ‘world’s best practice’ and inflated jobs figures. Public forests belong to everyone, and the government has a duty to make sure they’re managed in the public interest. Having a full suite of information can only help in this regard.
Keith, H., Mackey, B. G. & Lindenmayer, D. B. Re-evaluation of forest biomass carbon stocks and lessons from the world’s most carbon-dense forests. Proceedings of the National Academy of Sciences 106, 11635-11640, doi:10.1073/pnas.0901970106 (2009).
Burns, E. L. et al. Ecosystem assessment of mountain ash forest in the Central Highlands of Victoria, south-eastern Australia. Austral Ecology 40, 386-399, doi:10.1111/aec.12200 (2015).
Clean Energy Regulator. Emissions Reduction Fund, auction results April 2016, <http://www.cleanenergyregulator.gov.au/ERF/Auctions-results/april-2016> (2016).
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