Visual Fuel Hazard Assessment in Eucalyptus salubris Woodlands Across Time Since Fire Chronosequence, Great Western Woodlands SuperSite, 2012

Understanding fire behaviour and vegetation flammability is important for predicting the consequences of fires. Visual assessments of fuel, such as those developed in Project Vesta, have been widely applied to facilitate rapid data acquisition to support fire behaviour models. However, the accuracy and potential wider application to other plant communities of Vesta visual fuel assessments has received limited attention. The Great Western Woodlands (GWW) region of south-western Australia supports the world’s largest remaining area of Mediterranean-climate woodland, which in mosaic with mallee, shrublands and salt lakes cover an area of 160 000 km2. Eucalyptus woodlands in this region are typically fire-sensitive, and fire return intervals recorded over recent decades have been much shorter than the long-term average. This has led to considerable conservation concern regarding the loss of mature woodlands, and has highlighted a need to better understand how fuel and vegetation flammability changes with time since fire. We visually assessed fuels using Vesta methods across 24 sites in a multi-century (10 to 260+ years since fire) time-since-fire sequence derived from growth ring-size relationships in fire-sensitive Eucalyptus salubris (gimlet) woodlands.

探究火灾行为与植被可燃性规律，对预测火灾灾害后果具有重要意义。基于Vesta项目（Project Vesta）开发的可燃物目视评估方法已被广泛应用，可实现快速数据采集，为火灾行为模型构建提供支撑。但现有研究对Vesta目视可燃物评估方法的准确性，以及其在其他植物群落中的潜在推广价值，关注度均较为有限。
澳大利亚西南部的大西部林地（Great Western Woodlands, GWW）是全球现存面积最大的地中海气候林地分布区，该区域与玛利灌丛（mallee）、灌丛草地及盐湖呈镶嵌状分布，总面积达16万平方千米。该区域的桉树林地普遍对火灾敏感，近数十年记录的火灾回归间隔远低于长期平均水平。这一现状引发了学界对成熟林地丧失的高度保护关切，同时也凸显出深入探究可燃物与植被可燃性随火灾后时长变化规律的必要性。
本研究针对火灾敏感的萨氏桉（Eucalyptus salubris，俗称gimlet）林地，依据年轮大小关系构建了火灾后时长跨度达百年的序列（火灾后10至260+年），并在24个样地中采用Vesta方法开展可燃物目视评估。