摘要
在火烧迹地调查的基础上,分析了滇中云南油杉Keteleeria evelyniana,华山松Pinusarmandii,云南松Pinus yunnanensis等3种树种在不同林火行为下的耐火性差异,确定了从树皮的阻燃性角度分析林木耐火性的研究方法。对3种树种的树皮的结构进行了调查,对树皮的平均厚度、含水率、导热系数、氧指数和热辐射作用下的质量损失过程和树皮内表面温度变化过程6个阻燃性相关因子进行了测定和分析。结果表明:①云南油杉树皮内皮层结构完整不开裂,外皮层疏松,平均厚度是云南松和华山松树皮的1.38和3.07倍,导热系数为云南松树皮和华山松树皮的67.66%和54.85%,氧指数是云南松和华山松树皮的1.25和1.33倍。在热辐射作用下,云南油杉树皮内表面升温速率低,热分解缓慢,阻燃性最强,云南松树皮的阻燃性次之,华山松树皮的阻燃性最差。②树皮阻燃性的不同造成了云南油杉、云南松和华山松树种间耐火性差异。根据3种树种树皮的阻燃性和林木耐火性差异提出了相应的森林消防措施。
In central Yunnan Province, from previously burned stands of Keteleeria evelyniana, Pinus yunnanensis, and Pinus armandii having different forest fire behavior, wood bark structure was analyzed to determine flame retardancy factors, such as average thickness, moisture content, heat conduction coefficient, oxygen index, thermal weight loss, and inner surface temperature of the wood bark during external heat radiation. Results showed that the flame retardancy was ： K. evelyniana 〉 P. yunnanensis 〉 P. armandii. Flame retardancy of the wood bark was the main cause of fire resistance differences among the three coniferous species. This was due to ： 1 ） the integrated internal bark layer and loose external bark layer of K. evelyniana, 2） an average thickness of wood bark in K. evelyniana that was 1.38 times greater than P. yunnanensis and 3.07 times greater than P. armandii, 3） a heat conduction coefficient of the wood bark in K. evelyniana that was 67.66% greater than P. yunnanensis and 54.85% greater than P. armandii, and 4） an oxygen index of the wood bark in K. evelyniana that was 1.4 times greater than P. yunnanensis and 1.6 times greater than P. armandii. Accordingly fire protection measures for the three species were put forward based on flame retardancy of the wood bark and fire resistance of the coniferous trees. Special measures needn＇t be done for Keteleeria evelyniana, removing surface litters and cultivation measures should be adopted for P. yunnanensis and P. armandii, cleaning combustibles around the bark especially should be done for P. armandii. [Ch, 3 fig. 3 tab. 11 ref.]
出处
《浙江林学院学报》
CSCD
北大核心
2007年第2期192-197,共6页
Journal of Zhejiang Forestry College
基金
云南省自然科学基金资助项目(2003C0021Q)
云南省昆明市科技局重点资助项目(06H114135)
关键词
森林保护学
树皮结构
导热系数
氧指数
阻燃性
forest protection
wood bark structure
heat conduction coefficient
oxygen index
flame retardancy
