Preserving old-growth forests is vital to saving the planet
Gavan McFadzean – June 22, 2009
SO WHERE are the world’s most carbon-rich forests? Not the tropical rainforests of the Amazon, Borneo or Africa’s Congo Basin, according to research by the Australian National University. They are the tall, old-growth mountain ash forests of Victoria’s Central Highlands — a 90-minute drive east of Melbourne.
The researchers studied 132 forests from around the world to discover the regions that stored the most carbon. Their findings, published in the US-based Proceedings of the National Academy of Sciences, one of the world’s most-cited scientific serials, is a surprise because conventional wisdom says that tropical forests store the most carbon.
So why our forests? The conditions are perfect. These forests occur at a confluence of environmental conditions that lead to high rates of plant growth and, because they are cooler, decay rates are slower. In short they grow fast but decay slowly. And they are very old — at least 350 years, growing dense heavy wood. That’s important because the amount of carbon stored is due to volume and density. Also, these trees have not been subjected to logging.
The problem is, these very same forest types are being intensively logged for woodchips, mostly bound for Japan. These trees are not only the best at producing carbon; unfortunately for them, they are also some of the best for producing high-quality paper. To add insult to injury, several of Melbourne’s water catchments are among those logged.
ANU science shows that for as long as these forests are logged, their carbon-carrying capacity is reduced by up to 60 per cent, not to mention the emissions from logging and post-logging regeneration burns. If we stopped logging all the forests of south-eastern Australia, and we now have enough wood in plantations to do that, we would avoid emissions equal to 24 per cent of the 2005 Australian net greenhouse gas emissions across all sectors.
Ironically, the plantation-based timber industry is under great economic stress, with several major wood plantation growers in receivership. This is the right time for Premier John Brumby to develop an integrated industry rescue and climate package, which creates green jobs in the plantation sector and focuses management of our native forests on emissions reduction.
Another reason why these forests are so carbon dense is because they evolved with fire.
Yes, the Black Saturday fires did pass through some of these forests, but most of the carbon remains in the forest. This is because it is in big old trees and dead trunks, and in the soil. Therefore, the proportion of total carbon lost in the fire is surprisingly small compared with logging. Also, many trees survive fire in less intensely burnt patches, facilitating regeneration. But logging these forests makes them more vulnerable to fire because it fragments and dries out the landscape, replacing fire-resistant tall forests and a wet rainforest understorey with young eucalypts and a much drier understorey.
This research (combined with research released by ANU last year) demonstrates how important it is for the Federal Government to assess how much carbon could be stored in Australia’s native forests, how much greenhouse gas could be prevented from entering the atmosphere if we protect them from logging, and what their long-term ability to keep on pulling carbon dioxide out of the atmosphere actually is.
It also suggests that there is a serious new option to reduce our greenhouse gas emissions.
The Federal Government has made provision for complementary measures to be developed to supplement the carbon pollution reduction scheme. Clearly there is scope to develop a package to reduce emissions and protect and restore the carbon stored in our native forests. Such a package could prevent millions of tonnes of carbon dioxide being released.
We need to start recognising the value of these forests to climate change mitigation. The Government should provide incentives so that state governments and private land owners are rewarded for protecting and restoring the carbon stocks found in natural forests under their control.
Everyone is concerned with emissions from logging and tree clearing in developing countries, but the Government needs to ensure that the Copenhagen agreement also provides policies that give incentives to protect and restore carbon stocks in developed nations.
We knew these forests should be protected because they are our water catchments and habitat for endangered species such as the Leadbeater’s Possum, Victoria’s faunal emblem. Now it turns out they are the world’s largest carbon banks and their protection should be a critical part of any response to climate change by Prime Minister Kevin Rudd and Premier John Brumby.
Will the public interest finally take precedence over that of the woodchippers? Surely these forests have put an irrefutable case for their protection.
Gavan McFadzean is the Wilderness Society Victorian campaigns manager.