When “the science” defies common sense and ignores real expertise

Recently, front page headlines in The Age and Sydney Morning Herald screamed "Logging likely had significant effect on summer fires: scientists". The story, also covered by the Guardian Australia and the ABC, reported on a research paper claiming to provide 'compelling evidence' that timber production had a 'significant effect' on last summer's Victorian and NSW bushfires. The media coverage, included extensive quoting of the paper's lead author, ANU Professor David Lindenmayer, and one of the other four co-authors, UQ Professor James Watson, effectively urging State Government's to close timber industries to reduce the frequency and severity of future bushfires.

However, the quoted research paper was a mere 2-page 'comment' published in the journal, Nature Ecology and Evolution. This 'comment' included 2 maps, 4 small photos, cited 21 references and described itself as a "summary of recent scientific evidence of the impacts of forestry on these fires". It concluded with a 400-word discussion of "strategies to limit future catastrophic conflagrations".

That what is essentially just a very small literature review, with no new analysis, was able to generate a front-page headline in major daily newspapers and a 15-minute ABC radio interview of one of its co-authors (Watson), arguably speaks volumes for university public relations units and the determination of some conservation scientists to drive public opinion and reshape government forest policy.

This should be of some concern to the broader scientific community given the sensationalising that is inherent to turning an inconsequential scientific 'comment' into something far more significant than what it actually is. In particular, strategically timing its promotion to coincide with notable events – in this case, the start of State and Federal bushfire inquiries and announcements of limited salvage timber harvesting in some burnt forests – may well generate the best media coverage, but can also create the perception of an inappropriate academic agenda that may ultimately damage, rather than enhance, a university's brand.

More important than this is the potential for unwarranted media hype to pervert public policy based on flimsy grounds that ignore common sense and the far greater knowledge of forest scientists and field forestry practitioners. Collectively the 'comment' and the associated media promotion by two of its authors, provides a mix of highly questionable assertions and exaggerations, including:

• That logging has had 'severe impacts' on almost 200 forest-dependent threatened species, and has profound effects on fire severity and frequency;
• That post-fire salvage logging 'can impair recovery and make regenerating forests more prone to further fires';
• Parts of the forest industry are 'now calling for increased logging' within both burnt and unburnt forests;
• Logging increases subsequent wildfire severity by leaving 'large amounts of debris (up to 450 tonnes per hectare)' on the forest floor;
• Logging increases fire risk by opening up the forest to wind and sunlight thereby making it 'far drier';
• Prescribed (fuel reduction) burning is 'only effective when done within kilometres of dwellings and very regularly (repeated), around every three years';
• That due to past logging, East Gippsland forests are burning more frequently than their natural fire interval, which is implied to be from 50 – 150 years.

The first two points don't stand-up to scrutiny when viewed in a landscape context. It is simple common sense that while a very small-scale, scattered, and renewable activity such as harvesting and regrowing patches of forest, may have some minor localised impacts, it cannot have 'severe impacts' on landscape-scale parameters such as biodiversity conservation or fire spread, severity, and frequency. Ditto for post-fire salvage harvesting, which typically occurs in substantially less than 1% of burnt forests.

Claiming that elements of the forest industry are calling for an expansion of logging is also highly questionable given that the cited Australian Forest Products Association document is actually advocating better fire prevention through increased fuel reduction by burning and mechanical means in close proximity to towns and alongside major roads. Mechanical fuel reduction may produce some usable logs, but is a far cry from an expansion of logging, especially given that the timber industry stands to be substantially diminished by the loss of designated harvestable forests in the recent bushfires.

Claiming that logging increases subsequent wildfire severity by leaving up to 450 tonnes of debris on the forest floor is just disingenuous, especially given the background of three of the 'comment's' authors. Notwithstanding that the average amount of logging debris is hundreds of tonnes per hectare less than this, these three authors would be well aware that this debris is routinely removed by post-harvest burning in the process of site regeneration. Indeed, during Victoria's 2009 'Black Saturday' bushfires, regenerating logging coupes of up to 7-years old were mostly left unscathed due to a lack of ground fuels.

The notion that logging makes Australian forests 'far drier' by opening them up to sunlight and wind was first articulated in 2009 by ANU conservation scientists on the basis of a small literature review which was largely focussed on overseas rainforests with closed crown canopies. While suddenly opening a closed rainforest canopy can have dramatic drying effects, Australia's eucalypt forests have open canopies and any drying effects of logging them are therefore far less pronounced.

Asserting that fuel reduction burning is virtually ineffective in most circumstances simply exemplifies a lack of practical experience of either the burning itself, or of fighting wildfires where the benefits of previous fuel reduction are obvious. Unfortunately, similarly ill-conceived public comments from arms-length conservation scientists dismissing fuel reduction burning have been a regular feature of the aftermath of the recent bushfires, and constitute a significant threat to future fire management and indeed to the forests themselves.

The implied assertion that East Gippsland's forests naturally burn at greater than 50-year intervals was staggering to most forest scientists and practitioners who have spent time working in an area which is part of one of the three most fire-prone regions in the world. While the region includes some high elevation, wet forest types that would have naturally long fire intervals, the majority of the region's forests are in drier foothill and coastal areas that would naturally have burnt far more frequently, especially given the propensity for dry lightning storms to ignite many fires each summer.