Nonlinear Effects of Stand Age on Fire Severity

Abstract We quantify the relationship between forest stand age and fire severity using a detailed case study of Mountain Ash ( Eucalyptus regnans Muell) forest burned in south‐eastern Australia in 2009. We focused on two important areas of Mountain Ash forest that feature a range of growth stages and disturbance histories. Using probit regression analysis, we identified a strong relationship between the age of a Mountain Ash forest and the severity of damage that the forest sustained from the fires under extreme weather conditions. Stands of Mountain Ash trees between the ages of 7 to 36 years mostly sustained canopy consumption and scorching, which are impacts resulting from high‐severity fire. High‐severity fire leading to canopy consumption almost never occurred in young stands (40 years) stands of Mountain Ash. We discuss the significant forest conservation and management implications of these results for Mountain Ash forests as well as other similar biomes, where high‐severity fire is a common form of disturbance.