摘要
【目的】计划烧除是当前应用最广泛有效的森林可燃物管理措施。研究云南松Pinus yunnanensis林地表可燃物进行计划烧除时的火行为特征,可有效清理林地易燃物,降低林地火烧可能性,实现林火管理以预防为主的目的。【方法】使用点烧下山火技术在云南松林开展计划烧除。森林防火期内防火前期,在滇中地区新平县照壁山云南松连续分布区进行外业调查,包括样地设置和野外计划烧除点烧试验,记录烧除过程中火行为的动态变化,包括火蔓延速度、火线强度、火焰温度和高度等,评估烧除效果。【结果】滇中地区防火前期,云南松林地表可燃物含水率为11.99%~12.06%,处于干燥、易燃状态。烧除试验表明:火蔓延速度为0.14~0.29 m·min^(-1),火线强度为147~332 kW·m^(-1),火焰温度为386~578℃,火焰最大高度为0.9 m。不同可燃物类型烧除时火行为参数差异显著(P<0.05),但均为低强度火。云南松林的平均枝下高达7 m以上,可燃物垂直连续性较差,林下计划烧除火焰很难蔓延到树冠,不会形成树冠火。花脸率占5.00%,整体烧除率为59.00%~75.00%,达到了预期效果,能有效调控可燃物。【结论】云南松林计划烧除火蔓延速度缓慢,为稳进地表火(蔓延速度小于4.0 km·h^(-1)),可燃物燃烧彻底;火线强度小于750 kW·m^(-1),为低强度火,计划烧除为控制性火烧,不会跑火;平均烧除率为63.05%,烧除效果良好,能调控易燃可燃物载量,达到预防森林大火的目的。
[Objective]Prescribed burning is the most widely used and effective management measure for forest fuels.This study aims to reveal the behavior characteristics of prescribed burning in Pinus yunnanensis forest,so as to effectively clean up the forest land combustibles,reduce the possibility of forest fire,and realize the goal that forest fire management should focus on prevention.[Method]Downhill fire technology was employed as prescribed burning in P.yunnanensis forest.In the early stage of the fire prevention period,field investigation was conducted in the continuous distribution area of P.yunnanensis in Zhaobi Hill,Xinping County in central Yunnan Province,including sample plot setting and prescribed burning test to investigate the characteristics of fuels and record dynamic changes of fire behavior during the burning process,such as fire spreading rate,fireline intensity,flame temperature and height.[Result]In the early stage of fire prevention,the moisture content of surface fuels in the forest was 11.99%−12.06%,which was dry and flammable.The burning test showed that the fire spreading speed was 0.14−0.29 m·min^(-1),the fireline intensity was 147−332 kW·m^(-1),the flame temperature was 386−578℃,and the maximum flame height was 0.9 m.The parameters of fire behavior differed significantly among different surface fuels(P<0.05),but they were all low-intensity fires.The average under-branch height of P.yunnanensis forest was more than 7 m,and the vertical continuity of surface fuels was poor,so it was difficult for the understory burning flame to spread to the canopy.The unburned land rate accounted for 5.00%and the overall burning rate was 59.00%−75.00%,which achieved the expected effect and could effectively control combustibles.[Conclusion]The burning and fire spreading speed in P.yunnanensis forest is slow,belonging to stable surface fire,with spreading speed less than 4 km·h^(−1),and the surface combustibles burn thoroughly.Fireline intensity is less than 750 kW·m^(-1),which is a low-intensity fire and manually controllable.The average burning rate is 63.05%and the burning effect is good,and the load of flammable and combustible materials can be regulated to prevent forest fires.
作者
王劲
张文文
王秋华
曹恒茂
张曦妍
白万辉
李晓娜
高桂清
WANG Jin;ZHANG Wenwen;WANG Qiuhua;CAO Hengmao;ZHANG Xiyan;BAI Wanhui;LI Xiaona;GAO Guiqing(Yunnan Key Laboratory of Forest Disaster Warning and Control,School of Civil Engineering,Southwest Forestry University,Kunming 650224,Yunnan,China;Forestry and Grassland Bureau in Xinping County,Yuxi 653400,Yunnan,China;School of Geography and Eco-tourism,Southwest Forestry University,Kunming 650224,Yunnan,China)
出处
《浙江农林大学学报》
CAS
CSCD
北大核心
2023年第4期828-835,共8页
Journal of Zhejiang A&F University
基金
国家自然科学基金资助项目(31960318,32160376,31901322)
云南省教育厅研究生科学研究项目(2022Y606)。
关键词
森林可燃物
林火管理
计划烧除
低强度火
云南松林
forest fuels
forest fire management
prescribed burning
low-intensity fire
Pinus yunnanensis forest
