Science must determine our forestry future

Assessing the impact of forests and forest harvesting on carbon emissions needs to be based on scientific research and physical evidence. All involved in the forest debate need to put past prejudices behind them. [28 October 2008 | Peter Boyer]

When David Bartlett told a reporter last week that he didn’t think old-growth logging in Tasmania was “necessarily” related to climate change, he did so with the best of intentions: to look after his people.

Right now, forest harvesting is important to Tasmania, and stopping work in mature native forests would be felt by many in our rural communities as a severe blow. It’s no surprise that there’s a lot of resentment about talk of change.

Nor is it surprising that we Tasmanians tend to think that forestry here shouldn’t be compared with logging the tropical forests of countries like Indonesia and Papua New Guinea, where corruption is rife and regeneration tends to be off the agenda. And we’d be quite right – if these were the only considerations.

But there’s another, deeper question to deal with in forestry, which goes to the heart of our whole future existence. It comes down to the physical reality of a forest. Trees are trees, wherever they are. And being trees, they store a lot of carbon.

In tackling climate change, we’ve come to see that there’s no substitute for good science. If science says that replacing existing native forest with new seedlings causes no net loss of stored carbon, then on that score we shouldn’t change current forestry practices. If it says that seedlings can’t replace the carbon lost in such logging, then we’d better do things differently.

In recent years, looking at how trees obtain, store and release carbon, scientists have examined the ecology and structure of the whole forest – not just its timber species but its smaller trees and shrubs, its tiny life forms, its litter, soils and rocks. They’ve found that mature forests are incomparable carbon stores, in Tasmania just as everywhere else.

The science says that removing such forests, even on the coupe-by-coupe scale practised in Tasmania, and taking account of all carbon retained in timber and paper, means a net release of hundreds of tonnes of carbon dioxide per hectare. It says that the commercial forests and plantations that replace them cannot come close to making up the loss.

We need to know the level of our forestry emissions. Mr Bartlett correctly told The Australian’s Matthew Denholm that Kyoto Protocol rules aren’t much help in determining such emissions, but he then he cited the same tainted Kyoto figures to support his notion that Tasmanian forestry isn’t very important in the scheme of things.

All available science points to the conclusion that clear-felling mature forest ranks as Tasmania’s number one source of carbon pollution. What’s lacking is the official record.

I’m not a forest activist, and have never campaigned against logging. I was actually employed by the Forestry Commission in the 1980s. In times past I have tended to the view that we need a “balanced” position on exploitation or otherwise of our natural resources.

But the climate threat has changed everything. The forestry debate is no longer just about jobs and wilderness – or however else we may have framed it in the past. We must now consider whether today’s logging activities jeopardise our long-term future.

Science supports the forest industries’ claim that young, growing trees are good at capturing atmospheric carbon. The problem seems to be in the ensuing assumption that it’s therefore a good thing to get rid of a mature native forest and replace it with seedlings.

A report this year by an Australian National University team led by Prof Brendan Mackey said that Australian forests have far larger carbon stocks than was previously recognised. Prof Mackey was accused of bias because his project is partially funded by the Wilderness Society. But the report, based on real field data, was peer-reviewed, and the ANU strongly defended its scientific integrity.

A number of other published scientific papers dating back to the 1990s support the Mackey team’s findings, and a Forestry Tasmania research project completed in 2001 found that clear-felling caused a large loss of carbon to the atmosphere.

I can find no published scientific research to support a counter-view. Non-scientific literature, including the 2007 MBAC consultants’ report for Forestry Tasmania, skirts around the carbon storage issue, highlighting instead the benefit of long-term sequestration by new, growing forests.

Effectively, forestry interests are asking us to put science aside and believe them when they say that clear-felling mature forests presents no problem.

If they’re right, then they should be highly motivated to get the science together to prove it. What’s stopping industry or government from collecting comprehensive, verifiable local data on carbon retained and carbon lost from logging operations, and having the results published in the peer-reviewed scientific literature?

If and when science produces an alternative position it will be reasonable to shift ground on this. Until then we should call a halt to logging in Tasmania’s mature native forests.

Some rural communities may feel threatened by such talk, but I don’t believe they should. In the first instance, today’s plantations will remain available as renewable wood resources.

And if state and federal governments accept science’s current findings about native forest carbon, and acknowledge that tropical and temperate logging emissions should be treated basically in the same way, then an economic solution is at hand.

Under a fully-functioning emissions trading scheme, communities managing forests as carbon stores – including all the effort that must go into reducing wildfire risk – will gain a substantial and sustained financial return from protecting this matchless natural resource.

• This weekend, the Sustainable Living Expo and the Future Tasmania Showcase will be at the Hobart City Hall and the Bahai Centre of Learning during Saturday (with the Expo continuing on Sunday). Both events are to be launched at the Bahai Centre at 6 pm on Friday.

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