Forest burn facts

I urge your readers not to be fooled by misleading claims from Sustainable Timber Tasmania spokespeople who suggest that logging and regeneration burning on clear-felled forest coupes enhances public safety by reducing wildfire risk (Mercury, April 17). The opposite is true. This is made quite clear by evidence produced by Australian forest scientists who have international reputations and respect for their research.

Professor David Lindenmayer’s latest book, The Forest Wars, is underpinned by his more than 40 years of evidence gathering in Australian native forests.

Lindenmayer takes a myth-busting approach in this plain-talking and readable book. Lindenmayer’s book is not negative, he specifies courses of action that will improve public safety related to wildfires. Lindenmayer identifies four factors that explain the repeated observations that heavily logged forests are much more likely to burn than undisturbed ones. Forest debris left in coupes adds to fuel loads.

Logged forests have drier soils and more flammable vegetation because younger trees use a lot more water than mature ones. Higher wind speeds occur where forests have been opened up by logging. Closely spaced young trees in regenerated forests (and even aged plantations) greatly increase the likelihood of fire gaining access to the canopy and creating a dangerous crown fire that spreads rapidly. After clear-felling, typically over 50 per cent of the forest biomass remains on the coupe floor and is later burnt. A Forestry Tasmania scientist published research in TasForests in 2001 estimating that about 700 tonnes of carbon dioxide are produced per hectare of burnt clearfell coupe. Around 90 per cent of timber removed from native forest coupes is pulped for paper and cardboard, only 2-3 per cent ends up as a long-term carbon store in houses and furniture.

Frank Nicklason North Hobart