The Burning Question Again


Country burned twice in less than 10 years deep red. Map Dr Tom Fairman

The time of year when the Department of Environment Land Water and Planning sets fire to the bush in controlled burns, and to the debris in logged coupes, is now with us. As a seasonal employee of the department forty years ago, I worked on these tasks. Also at my home in Ensay on a few acres, I would often burn some of the grasses and other areas I could not mow or otherwise reduce the fuel load for fire protection. These fires were of low intensity and very small, although twice in thirty years I had small burns get away from me. With global warming the task now is more complicated and difficult, as we need to both protect trees and the bush and limit burning as much as possible (for an earlier blog see here).

The logging industry is at the heart of this problem. It is quite clear that the bush is far more valuable as a carbon store than as timber for woodchips and paper. By ceasing logging, as any reasonable government that accepts the science would have done years ago, solves part of the problem. There remains the question of the emissions produced by the large scale, so called ‘controlled’, burns carried out in the name of bushfire protection.

Philip Zylstra Research Fellow on flammability and fire behaviour from the University of Wollongong noted that at “the heart of our traditional approach are hand-drawn dots on a graph from a leaflet published by Australian bushfire expert Alan McArthur in the 1960s. [There are] nine data points telling us that if we halve the fuel load – the leaf litter on the ground – we can halve the speed of the fire. It has never been backed by evidence, but in the absence of something better it became the bedrock of Australian fire management. One rule for all forests: burn them.” Our black summer bushfires have clearly shown that country that recently burned will burn again and that under severe conditions controlled burns are ineffective. Zylstra supports low intensity small scale ‘Aboriginal’ style burning, which has debatable relevance to Gippsland.

Research by David Cheal after the Black Saturday fires in 2009 has noted that all “fuel treatments (i.e. controlled or hazard reduction) were more effective when undertaken close to houses. For example, 15% fewer houses were destroyed if prescribed burning occurred at the observed minimum distance from house (0.5km) vs. the mean distance of 8.5 km. The results imply a shift in emphasis away from broad-scale fuel reduction to intensive fuel treatments close to property will more effectively mitigate impacts.”

With global warming, the forestry practices of fifty years ago are no longer valid. It is time to end logging, and most burning, as quickly as possible.