Abstract
Extreme fire seasons characterised by very large mega-fires have demonstrably increased area burnt across forested regions globally. However, the effect of extreme fire seasons on fire severity, a measure of fire impacts on ecosystems, remains unclear. Very large wildfires burnt an unprecedented area of temperate forest, woodland and shrubland across south-eastern Australia in 2019/2020, providing an opportunity to examine the impact of extreme fires on fire severity patterns. We developed an atlas of wildfire severity across south-eastern Australia between 1988 and 2020 to test (a) whether the 2019/2020 fire season was more severe than previous fire seasons, and (b) if the proportion of high-severity fire within the burn extent (HSp) increases with wildfire size and annual area burnt. We demonstrate that the 2019/2020 wildfires in south-eastern Australia were generally greater in extent but not proportionally more severe than previous fires, owing to constant scaling bet
February 17, 2021
Over the past decade, fire scientists have made major progress in understanding climate-fire relationships at large scales, such as across western North America.
The millions of people affected by 2020’s record-breaking and deadly fires can attest to the fact that wildfire hazards are increasing across western North America.
Both climate change and forest management have been blamed, but the relative influence of these drivers is still heavily debated. The results of a recent study show that in some ecosystems, human-caused climate change is the predominant factor; in other places, the trend can also be attributed to a century of fire suppression that has produced dense, unhealthy forests.