可燃物处理对大兴安岭地区主要林型火行为的影响  

Impacts of Fuel Treatment on Potential Fire Behavior of Main Forest Types in Daxing’anling

作　　者：宗学政 田晓瑞[1] Zong Xuezheng;Tian Xiaorui(Research Institute of Forest Ecology,Environment and Protection,Chinese Academy of Forestry Key Laboratory of Forest Protection of National Forest and Grassland Administration,Beijing 100091)

机构地区：[1]中国林业科学研究院森林生态环境与保护研究所,国家林业和草原局森林保护学重点开放性实验室,北京100091

出　　处：《林业科学》2021年第2期139-149,共11页Scientia Silvae Sinicae

基　　金：国家重点研发计划项目(2018YFD0600205);国家自然科学基金项目(31770695)。

摘　　要：【目的】模拟研究不同强度的可燃物处理对大兴安岭地区典型森林的火行为影响,为开展可燃物管理提供科学依据。【方法】在2019年火险期,分别对大兴安岭地区兴安落叶松林、白桦林、兴安落叶松白桦混交林等天然林和兴安落叶松与樟子松人工林进行可燃物调查和清理。每种林型分别设置3块样地(20 m×20 m),每块样地再分别设置4块小样地(10 m×10 m)。对每块样地进行林分结构调查,然后对4块小样地分别进行可燃物处理,包括割除枯死灌木和草本、清理枯枝和地表凋落物等。按可燃物处理程度分为未处理、低、中和高强度处理4个等级。低强度处理后林内无易燃及枯死灌草、地表无大型可燃物(>10 h),可燃物梯最小高度为3 m,中强度处理后倒木、灌木及小乔木全部清除,高强度处理后地表存留可燃物不会支持火的持续燃烧和蔓延。调查可燃物处理后的可燃物空间分布。利用可燃物特征分类系统(FCCS)分别模拟各林分在火险期内一般天气情景和干旱情景下的火行为。一般天气情景下,模型输出的指数包括地表火蔓延速度、火焰高度和火强度指标;干旱情景下,模型输出指数为潜在地表火(火强度、火焰高度和蔓延速度)及潜在树冠火行为(树冠火发生指数、蔓延指数和蔓延速度指数)。【结果】模拟结果显示,低强度可燃物处理后,兴安落叶松天然林和人工林地表火蔓延速度分别降低51.6%和42.8%,火焰高度分别降低33.6%和39.4%,平均火强度分别降低22.8%和34%;而兴安落叶松白桦天然混交林、白桦林和樟子松人工林的火行为变化不明显。中强度可燃物处理后,兴安落叶松白桦混交林、白桦林、兴安落叶松天然林、兴安落叶松人工林和樟子松人工林的地表火蔓延速度分别降低29.4%、37.1%、79.1%、83.3%和19.7%,火焰高度分别降低33.3%、29.8%、67.2%、69.7%和38.1%。高强度可燃物处理后,【Objective】The aim of this paper is to provide scientific reference on fuel management by analyzing the effect of the fuel treatments on fire behavior of the main forest types in Daxing’anling.【Method】In this study,three 20 m×20 m plots were set in each forest type during fire season of 2019,and four 10 m×10 m sub-plots were further divided in each plot.The forest types included natural forests of Larix gmelinii(Larch natural forest),Betula platyphylla(Birch natural forest),and coniferous and broad-leaf mixed forest(Larch and birch natural mixed forest),and plantations of L.gmelinii(Larch plantation)and Pinus sylvestris var.mongolica(Mongolian Scots pine plantation).The forest structure of each plot was investigated,and then four sub-plots were treated with combustible materials,including cutting dead shrubs and herbs,clearing dead branches and surface litter.The combustible materials in sub-plot were treated with four intensities(untreated,low,mid,and high intensive treatment)respectively.After low intensity treatment,there were no inflammable and dead shrubs and grass in the forest and large combustible materials on the surface(>10 h).After medium intensity treatment,all fallen trees,shrubs and small trees were removed.After high intensity treatment,the combustible materials on the surface would not support the continuous combustion and spreading of fire.The Fuel Characteristic Classification System(FCCS)was used to simulate fire behaviors for each plot under the ordinary weather scenario and drought scenario.【Result】The simulation results showed that the surface fire spread decreased by 51.6%and 42.8%for Larch natural forest and plantation under the ordinary weather scenario after fuel treatments in low intensity,respectively.The flame length dropped by 33.6%and 39.4%,and the fire intensity decreased by 33.6%and 39.4%.However,the surface fire behavior did not change significantly after the low intensity treatment in larch and birch natural mixed forest,birch natural forest,and Mongolian Scots p

关 键 词：可燃物特征分类系统 可燃物处理 火行为 

分 类 号：Q958.15[生物学—动物学] S154.5[农业科学—土壤学]