【作者】 李世友；

【导师】 舒立福；

【作者基本信息】 中国林业科学研究院 ， 森林保护学， 2014， 博士

【摘要】 滇中地处低纬度高原，地形高差较大，地貌复杂多样，立体气候明显，是云南和全国森林火灾的多发区与重灾区。特殊的气候、地形地势、森林类型和生产生活用火的多样性和复杂性，决定了滇中地区林火行为的复杂性和森林防火任务的艰巨性。研究滇中林区森林可燃物燃烧特性及林火行为特点，可以为正确认识滇中森林火灾发生规律及重点火险区治理提供科学依据。论文的主要研究内容、方法及结论有：①滇中地区主要森林木本植物活叶片的燃烧性排序与分类。为比较不同森林植物活叶的燃烧性，在防火戒严期内对滇中地区11种主要森林木本植物的活叶片进行了高氧气氛下的燃烧试验，测定和计算了各种植物活叶片的含水率、单位面积质量、燃烧线速率、燃烧面积速率、燃烧质量损失速率、叶脉损毁程度、面积损毁程度、质量损毁程度等共计14个具体因子，运用因子分析方法对11种植物的燃烧性进行了排序，即炮仗花杜鹃>云南樟>云南含笑>厚皮香>大白花杜鹃>光叶石栎>小白花杜鹃>水红木>元江栲>云南野山茶>野八角。分析表明，11种活叶片的燃烧性可分为4类，其中极易燃类1种，易燃类4种，可燃类3种，难燃类3种。②滇中地区主要森林木本植物中小径级活枝的燃烧性排序与分类。为综合分析和比较植物活枝的燃烧性，在森林防火紧要期内，对昆明地区15种常见木本植物中小径级的活枝进行了热辐射引燃试验，对小径级的活枝进行了氧指数试验。在测定样品直径、含水率、引燃时间、有焰燃烧时间、试验过程中烟气温度和质量损失变化过程等基础上，提出并计算了能够表征活枝燃烧性能的综合燃烧特性参数S。根据该参数对15种植物中小径级活枝的燃烧性能进行了排序，即：云南松<野八角<华山松<滇青冈<地盘松<云南樟<厚皮香<大白花杜鹃<炮状花杜鹃<云南含笑<小白花杜鹃<南烛<光叶石栎<元江栲<云南野山茶。氧指数试验结果表明，15种植物的小径级活枝均具有较强的阻燃性，根据氧指数及试验现象将15种植物的小径级活枝分为3类，其中难燃类4种（大白花杜鹃、野八角、厚皮香、南烛）、可燃类7种（云南含笑、云南松、地盘松、华山松、滇青冈、云南樟、云南野山茶）、较易燃类4种（小白花杜鹃、炮状花杜鹃、光叶石栎、元江栲）。直径、含水率、油脂含量等理化性质是造成两种试验条件下燃烧性差异的主要原因。③滇中地区3种主要针叶树种松针燃烧的烟密度等级及其影响因素。为了解针叶燃烧的烟密度等级及其影响因素，进行了老叶、新叶和凋落叶烟密度试验。分析表明，对于云南松、地盘松、华山松活叶和凋落叶，随着质量的增加，燃烧的烟密度等级增加，但并不与质量呈正比。在干物质质量相近的情况下，凋落针叶燃烧的烟密度等级随含水率的增加而增加。④基于FDS的滇中森林火行为模拟研究。构建了基于FDS的森林可燃物模型，对滇中森林火行为进行了研究，包括特定可燃物和环境条件下森林燃烧的初始蔓延速度，火环境对燃烧速率、热释放速率的影响等。分析表明，在火环境条件相近的情况下，用FDS软件模拟推算的森林地表火蔓延速率与通过燃烧试验测定的华山松林、云南松林细小可燃物层燃烧初始蔓延速度相近，用FDS进行森林地表火模拟是可行的。更多还原

【Abstract】 Central Yunnan is a region with frequent and strong forest fires, both within the provinceand within China. The area is located on a low latitude plateau, with a large elevationdifference, complex and diverse topography, and clear three-dimensional climate. The uniquecharacteristics of climate, topography, forest type, and diverse fire sources produce acomplexity of forest fire behaviors and the difficulty of fire prevention. Research oncombustibility of forest fuel and fire behaviors can provide a basis for an understanding of theforest fire occurrence pattern and comprehensive fire management in the area. The mainresearch content, methods and conclusions in this paper are as follows:①Study on combustibility using ordering and sorting of living leaves from commonnative woody species. To compare the combustibility difference of plant species, combustionexperiments of live leaves from11common native woody plant species were conducted withan oxygen index measuring instrument under high oxygen concentration during the peak forestfire season. Moisture content, mass per unit area, burning rate, and damage extent of the liveleaves were measured and calculated. The combustibility orders based on factor analysis fromstrong to weak were: Rhododendron spinuliferum> Cinnamomum glanduliferum> Micheliayunnanensis> Ternstroemia gymnanthera> Rhododendron decorum> Lithocarpus mairei>Rhododendron siderophyllum> Viburnum cylindricum> Castanopsis orthacantha> Camelliapitardii> Illicium simonsii. The results showed that the live leaves of11species could bedivided into four categories:1was very inflammable,4were inflammable,3were combustible,and3were difficultly inflammable.②Study oncombustibility ordering and sorting of live branches of main forest woodyspecies. To understand the combustion characteristics of15common native woody plantspecies, a thermal radiation ignition experiment with small and medium size branches and anoxygen index experiment with small size branches were conducted during peak forest fire season. Based on the sample’s diameter, moisture content, time to ignition, quenching time offlaming combustion, smoking temperature， and weight loss, an integrated combustionparameter (S) reflecting the combustion characteristics was proposed. According to thecalculated S, the combustion order of the test tree species was Pinus yunnanensis<I. simonsii <Pinus armandii <Cyclobalanopsis glaucoides <Pinus yunnanensis var. pygmaea <C.glanduliferum <T. gymnanthera <R. decorum <R. spinuliferum <M. yunnanensis <R.siderophyllum <Lyonia ovalifolia <L. mairei <C. orthacantha <C. pitardii. The oxygen indexexperiment indicated that the small size live branches of the15tree species all had obviousflame-retardant characteristics, of which4(R. decorum, I. simonsii, T. gymnanthera and L.oralifolia) were difficultly inflammable，7(M. yunnanensis, P. yunnanensis，P. yunnanensis var.pygmaea，P. armandii，C. glaucoides，C. glanduliferum，and C. pitardii) were combustible，and4(R. siderophyllum，R. spinuliferum，L. mairei，and C. orthacantha) were inflammable.The reasons for the difference between the classifications derived by the two experiments wereanalyzed.③Study on the smoke density rating of3main coniferous species. In order to analyzeand compare the smoke density rating of conifers in burning, experiments using old and newconifers, litter from P. yunnanensis, P. armandii, P. yunnanensis Franch.var. pygmaea Hsuehwere conducted. The results showed that the smoke density rating of these3species increasedwith mass, but were not proportional. The smoke density rating of the litter increased withmoisture content, as with the case of a similar mass of dry matter.④Simulation study on forest fire behavior based on Fire Dynamics Simulator (FDS). Thepaper modeled forest fuel with FDS, and studied the forest fire behaviors, including the initialspread rate of forest burning under certain conditions of fuel and environment, the affect ofenvironment factors on forest burning and heat release rate. The result showed that the forestsurface fire spread rate calculated with FDS was similar to the initial spread rate of litter of P.yunnanensis and P. armandii measured by the burning experiment, and thus FDS modelpredictions are likely to provide a close approximation to actual conditions, at least in this regard.更多还原