Victoria plans thousands of kilometres of fuel breaks, but evidence suggests they could damage endangered forests, increase carbon emissions and deliver limited protection against the most dangerous bushfires.

The Victorian Government is planning to construct up to 6,000 km of fuel breaks across the state. Some of them will be through areas of high conservation value forest. We briefly discuss the issues with these so-called fuel breaks and argue that the Victorian Government needs to rethink a policy that is likely to have a limited effect on fire behaviour, will do major damage to forest integrity, and will cost taxpayers heavily for limited return.

Large parts of southern Australia are facing enormous challenges with bushfire management, driven in part by climate change, but also the legacies of past logging operations which have made forests significantly more flammable and more fire prone. One strategy implemented in an attempt to tackle this problem is to establish vast networks of fuel breaks. At face value, it appears that these fuel breaks are supposed to halt the progress of fire across the landscape. However, embers can travel more than 500 metres to start new fires (and sometimes 10 times that distance or more). A 20–40 metre fuel break will do little to curb this problem. This is already well known to many fire managers and their response is that fuel breaks provide a place from which to do backburns and limit the spread of fires. But in tall, wet forests with very high levels of biomass, backburns on extreme fire days (when wildfires are difficult to control) will likely instigate extremely dangerous crown fires.

If fuel breaks will have a limited effect on stopping fire spotting and may potentially contribute to crown fires, why are they being constructed? One reason is that firebreak construction provides a source of timber for the native forest logging industry. This may explain why the Victorian Government has developed a State Forest By-Products framework to sell timber from operations like cutting firebreaks. The policy platform of the Victorian Forest Products Association states: “maintaining a formal ‘byproducts policy’ to ensure hardwood from fuel breaks, windthrow and health forest maintenance is utilised to its highest and best use”. This means that the Victorian Government provides commercially usable logs cut from fuel breaks and other forest management interventions to the native forest logging industry. This includes logs from fuel breaks cut across national parks.

Beyond questions of the effectiveness of the massive fuel break program across Victoria, there are serious environmental risks associated with their construction. For example, in the Central Highlands of Victoria, substantial parts of the fuel breaks will be cut through significant areas of cool temperate rainforest. These rare forest ecosystems rarely burn and, in many cases, actually can help mitigate the spread of wildfires. In the 2009 bushfires, cool temperate rainforests prevented the spread of those fires under moderate weather conditions due to their wet and shaded environments. Cool temperate rainforests are natural fire breaks in and of themselves. However, by clearing these rainforests, the fuel breaks dry out and become overgrown with grasses and shrubs that are susceptible to fire. In effect, the fuel break increases the risk of fires.

Fuel breaks have already been cut through alpine ash forests with more planned to be cut. These forests are formally classified as an endangered ecological community under Australian Government legislation. Past studies have indicated that alpine ash forests are already heavily fragmented and extensive firebreaks through them will exacerbate this problem. In addition, mapping work we have completed (using Victorian Government datasets) shows that the proposed routes for some of the fuel breaks will result in the removal of areas of old-growth alpine ash. It is critical to recognise how limited the remaining areas of alpine ash forest are – an estimated 0.47 per cent of the extent of this ecosystem remains in the Central Highlands region. Victoria has already lost 77 per cent of its old-growth forest in the past 25 years. It cannot afford to lose more of an already rare stand age class.

Another issue is that the construction of an extensive network of fuel breaks will result in the loss of a large number of old hollow-bearing trees. This is a significant concern given the dependence of a range of endangered and critically endangered species on this keystone resource. For instance, declines in species such as the southern greater glider and Leadbeater’s possum are strongly linked to declines in large old trees.

Finally, the construction of fuel breaks will lead to significant greenhouse gas emissions. At least 585 hectares are proposed for clearing as part of the planned fuel break network in the Central Highlands region alone. That clearing will reduce ecosystem carbon storage by approximately 168,000 tonnes of carbon (t C). Because much of this clearing will be in wet forests with exceptionally high carbon-carrying capacity, government models indicate initial clearing will generate approximately 245,000 tonnes of carbon emissions. A further 378,000 tonnes of CO₂ will be emitted over subsequent decades as dead biomass and soil organic carbon continue to decompose. Of course, extra carbon emissions add to the problem of climate change which is a contributor to increasingly severe fire seasons. Clearing forest to control fire risk while potentially increasing that risk is the antithesis of the policy’s stated aim.

The evidence doesn’t support the fuel break program. Victoria is poised to log an endangered ecological community, burn through taxpayer money, and add hundreds of thousands of tonnes of carbon to the atmosphere, all to build fuel breaks with no proven ability to stop a fire. Strip away the fire management rhetoric, and what’s left is logging with a fire management excuse. Based on the evidence to date, we suggest that the Victorian Government needs to rethink and abandon plans to establish vast areas of strategic fuel breaks across Victoria, and especially in currently intact forests of high conservation value.

The views expressed in this article may or may not reflect those of Pearls and Irritations.