OPENING LINES BURNING OFF THE ANSWER TO INTENSITY Source: https://arr.news/, Philip Hopkins, First Published March 25th, 2024 A major study after the devastating 2013/20 wildfires in Victoria and New South Wales found that prescribed burning dramatically reduced the intensity of the fires, according to a bushfire expert. Dr Tony Bartlett, a winner of the Australian Fire Service Medal (ATSM), said after 2019/20, a major study was undertaken to test the effectiveness of prescribed (fuel reduction) burning at a landscape scale in terms of reducing the severity of the wildfire in a wide range of forest ecosystems. Dr Bartlett was part of a three person panel that investigated the impact of the wildfires on Victoria’s Regional Forest Agreements. The major study examined 307 prescribe burns greater than 200 hectares that had been conducted in the previous five years and which were within the footprint of the 2019/20 wildfires. “It found that about half (48 per cent) of these prescribed burns resulted in significantly reduced wildfire severity,” said Dr Bartlett, writing in the Commonwealth Forest Association newsletter. “It also found that the more recent prescribed burns had a more positive impact on reducing fire severity, with 66 per cent of one-year-old burns having a positive impact compared to 42 per cent of fiveyear-old burns.” Dr Bartlett said Australian academics Professor David Lindenmayer and Associate Professor Philip Zylstra had made claims about the impact of prescribed burning on forest flammability. “None of the claims.. are supported by evidence from long term monitoring of replicated trials where prescribed burning has been conducted,” he said The academics in articles reproduced in the CFA newsletter argued that prescribed burning and logging made Australian native forests more flammable. They said prescribed burning should be confined to areas close to high-value assets and that. when fire is excluded for mare than 40 years, the native forests do not burn at high intensity because the vertical connectivity of the forest structure is reduced through natural ecological processes. In contrast, Dr Bartlett said the late Associate Professor Kevin Tolhurst studied the effects of repeated low-intensity preseribed fire in mixed species eucalypt forest in south east Australia using repeated trials (including no-burning sites) for almost 40 years. “He found there was no lose of species but the impact on understory plant species varied according to the nature of different species,” Dr Bartlett said. “My own observations at these research sites in October 2024 indicated there was significantly less understorey vegetation in the repeatedly burnt sites than in the unburnt control sites – which contradicts the Lindenmayer-Zylstra view that prescribed burning in eucalypt forests promotes dense flammable understorey vegetation.” Dr Bartlett said the academics’ propositions ignored the evidence of comprehensive fire research done by the CSIRO and state government land management 9 BUSINESS VIEW OCEANIA VOLUME 07, ISSUE 03
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