Bushfire submission
Submission to Victorian Parliamentary Inquiry
Submission to the inquiry by the
Parliamentary Natural Resource and Environment Committee
into Victorian Bushfires 2006/7
by Friends of Bass Valley Bush Inc Landcare Group
Assessing the value of fuel reduction burns
It will be helpful for the safety of the community and the conservation of biodiversity in this State for this inquiry into the Victorian bushfires in 2006/07 to require a scientific assessment of the effectiveness of fuel reduction burns on limiting the spread and intensity of wildfires. There has been little rigour to verify claims that fuel reduction burns are an effective fire management tool. Evidence needs to be produced demonstrating whether or not prescribed burns are beneficial in mitigating risk. Ample data must now be available to determine whether there is any discernable difference in fire behaviour in areas subjected to fuel reduction burns compared with those that had not been burned in recent years.
There is a highly vocal and critical lobby which seems to believe that the Department of Sustainability and Environment should dedicate more staff and funding to conduct large scale burns every year – but it is questionable whether that will decrease the incidence of wildfires. It seems unlikely, given the behaviour of fire and the expectation of increasingly hazardous summer weather conditions, that more frequent fuel reduction burns will make Victoria safer.
In hot, dry conditions such as those encountered this year it has been suggested by some farmers and CFA personel that reduction burns had little value in containing the wildfires. Firefighters acknowledged that areas which had been burned in recent years burned just as quickly as those which had not. There were cases of flames 10 metres high roaring across bare paddocks where there was seemingly no fuel load whatsoever. The evidence suggests it is the combination of heat, dryness of the air and soil and the strength of winds which are the determining factors in wildfire intensity and progress.
It makes little or no difference whether fire breaks are constructed 10 metres, 20 metres or even 100 metres wide. In the right (or wrong) conditions the fire will jump any break. The constructed breaks may provide some kind of relatively safe haven for firefighters but with wind as the main driver they do little to halt fire progress. Embers create spot fires a kilometre or more ahead of the firefront. Is the committee able to look at the long term implications for biodiversity of creating and maintaining significant cleared areas as firebreaks within regions which are essential habitat for wildlife? The fragmentation of vegetation has major biodiversity implications and has resulted in significant species loss. Some practioners involved in Natural Resource Management felt that these problems were gradually being addressed by spending public funds on revegetation projects and protecting the little remnant vegetation which remains in this State, but regular burns and the creation of temporary and permanent fire breaks compound the problems of habitat loss generated by development pressures.
It can be argued that Fuel Reduction Burns actually worsen the fire hazard by drying out the vegetation, making it potentially more fire prone. In this way regular burns can generate an even bigger fuel load, creating further risk of wildfire along with the clamour for more fuel reduction burns.
It has become clear that with constant burning over the years, the character of vegetation can be changed from wet to dry. The burns reduce the build up of mulch and shrub layers that are the first step towards the development of moist microclimates. They also affect the soil's ability to hold moisture and may change the soil profile.
Is the fuel load criterion effective in helping to mitigate risk?
Areas of clearfell regeneration are not subject to the same fuel load criteria as other areas of Forests and Reserves, even though the fuel load can be higher and presents a potentially greater risk than mixed-aged forest. Many foresters and fire officers seem to agree that areas of clearfell regeneration should not be burned for 20 years or so because of unacceptable damage to the commercial value of the timber. It seems that the fuel reduction burns generally take place in mixed age forest and reserves, with no regard for habitat, biodiversity or other values of the forests.
Some fire officers claim that regular fires are essential for the viability of many species said to be dependent on fire for germination, but they don't apply the same principle to clearfelled regeneration areas. Some forest blocks have large areas of regenerating forest less than 10 years old interspersed with buffers and corridors of older forest. Current asset protection policies inhibit regular burns in these areas. The committee may be able to assess whether or not the risks will be any greater if that policy is applied overall to mixed age forest.
Given Australia's current potable water supply difficulties, the implication of fuel reduction burns on water run-off yields, potential for siltation and other water quality issues also needs investigation.
March 2007
Philip Westwood
Friends of Bass Valley Bush Inc Landcare Group
email: bassbush@dcsi.net.au
Friends of Bass Valley Bush is a voluntary not for profit community-based Landcare Group operating in the Bass Valley in South Gippsland on private and public land
Philip Westwood is a farmer and environmental auditor.
An excellent paper was written by Dr Timothy Ingelsbee, Director of the Western Fire Ecology Centre which takes the view "We don't fight fires we fight the forest"
Read it at http://www.fire-ecology.org/research/soldiers_story.htm
Links to other submissions
Land and Biodiversity
