森林防火隔离带技术的变革与优势

以消减可燃物的方式预防和阻隔森林火灾是林火管理工作的核心。传统阻隔技术向遮荫型防隔火技术的演变已成为近10余年西方多林国家林火管理工作的重要走向。从林火的特点和蔓延基本规律出发, 遮荫型防火隔离带技术通过局部消减可燃物载量和规则化可燃物分布, 显著降低其可能形成的林火强度, 使大多数火灾自行熄灭。该项技术的实施不受区域和气候条件限制; 与传统全光式防火隔离带和生物防火林带相比, 不但工作量较小, 对林分植被和生态环境的干扰也较小。该项技术实现了偶发性林火的防控、森林健康及生态维护的有机结合, 以此替代传统防火隔离带技术效益显著。针对遮荫型防隔火技术的进一步研究工作应包括不同稀化程度林带潜在火行为和其防隔火效能的量化评估、林地局部可燃物稀化的高效作业机具以及伴随该项技术实施产生的大量生物质副产品的有效利用问题。

Innovation and Associated Advantages of Forest Firebreak Techniques

Prevention and control of forest fire via fuel treatment techniques is the core of forest fire management. In recent decades, an important trend has been observed in western countries with large coverage of forest, which witnesses a transition from the conventional ones to the shaded ones. The shaded fuelbreaks, established based on the characteristics of forest fires and its spreading law, are effective to reduce fire intensity and make most of wildfires self-extinguished by reducing wildland fuels and regularizing their spatial distribution in the band areas. This technique is applicable to any places, without any meteorological restrictions. Compared with the conventional open fuelbreaks and the biological fire-prevention belts, shaded fuelbreaks could be established and maintained with relatively low workload and less interventions on natural vegetation and their associated ecological environment. By implementing this technique, the prevention and control of coincidental wildfire are well achieved in combination with the maintenance of forest health and local ecosystem. As a result, the shaded fuelbreak technique is a good option to replace the conventional ones. Further research on the shaded firebreak technique should be emphasized on the following aspects:(1)fire behavior of forest fuels under thinning at different extents and the method for quantifying the capacity of the shaded fuelbreaks in stopping forest fire;(2)development of efficient operation equipment for constructing the shaded fuelbreaks;and (3)effective utilization of the large amount of biomass generated by implementing this technique.