室内模拟降雨对蒙古栎和红松凋落物床层饱和含水率的影响  

Effects of indoor simulated rainfall on moisture contents of litter beds of red pine and Mongolian oak

作　　者：张运林 孙萍[2] 满子源[2] ZHANG Yunlin;SUN Ping;MAN Ziyuan(School of Biological Sciences,Guizhou Education University,Guiyang 550018,Guizhou,China;College of Forestry,Northeast Forestry University,Harbin 150040,Heilongjiang,China)

机构地区：[1]贵州师范学院生物科学学院,贵州贵阳550018 [2]东北林业大学林学院,黑龙江哈尔滨150040

出　　处：《中南林业科技大学学报》2020年第9期1-10,共10页Journal of Central South University of Forestry & Technology

基　　金：贵州师范学院校级博士课题(2019BS005);国家自然科学基金项目(31370656);贵州省教育厅青年科技人才成长项目(黔教合KY字[2016]213)。

摘　　要：【目的】地表凋落物作为森林火灾的引火物,其含水率大小决定凋落物被引燃的难易程度和发生火灾后一系列火行为指标等。降雨作为林火预测预报中必不可少的气象因子,直接影响地表凋落物的含水率。但由于降雨的不确定性,其对凋落物含水率影响的研究较少。为了搞清降雨对凋落物含水率的影响,分析降雨条件下凋落物含水率动态变化和凋落物床层饱和含水率情况。【方法】以蒙古栎和红松地表凋落物为研究对象,设置不同床层密实度和初始含水率,利用降雨模拟器在室内模拟不同降雨量,每隔10 min称量一次凋落物床层至饱和,得到凋落物含水率动态变化情况,分析床层密实度、初始含水率和降雨量对2种凋落物床层饱和含水率的影响,并建立响应预测模型。【结果】降雨条件下2种凋落物床层含水率呈对数增加;不论蒙古栎还是红松,床层初始含水率对床层饱和含水率没有显著影响,饱和含水率受床层密实度和降雨量的影响显著。降雨量和床层密实度对凋落物床层饱和含水率的影响相互制约,随着床层密实度的增加,降雨量对饱和含水率的作用下降;不同凋落物床层密实度时,建立了Ms=a×exp(b×R)的床层饱和含水率预测模型,模型预测误差均在可接受范围内。【结论】本研究揭示了降雨对不同结构的凋落物床层含水率的影响,对于含水率预测模型研究和火险预报研究具有重要意义。【Objective】As the kindling material of forest fire,the moisture content of surface litters determines the probability of litters to be ignited and a series of fire behavior indexes after the occurrence of fire.Rainfall is an important meteorological element that plays an important role in forecasting forest fire.Rainfall affects the fire risk level by changing the moisture content of the litter bed on the surface;rainfall can increase the moisture content of litter beds,but the effect is very complex.To better understand the influence of rainfall on the changes in bed moisture content.【Method】The litter beds of Mongolian oak and red pine,which have different compactness and initial moisture content were constructed indoors.Under different rainfall conditions,litter beds were weighed every 10 min to obtain the change in moisture content of two litter type.【Result】The moisture content of the two litter beds increased logarithmically under rainfall conditions.Regardless of species,the initial moisture content of the litter bed had no effect on the saturated moisture content,and the compactness of the litter bed,the rainfall and their interaction had a significant effect on the moisture content of the litter bed.The influence of rainfall and compactness of the litter bed on the saturated moisture content are mutually restricted,as the compactness of the litter bed increases,the effect of rainfall on the saturated moisture content decreases.A prediction model for the change in moisture content with rainfall,in the form of Ms=a×exp(b×R),was established,and the error was within the acceptable range.【Conclusion】This research clarifies the influence of rainfall on the change in moisture content in the litter bed and is of great significance for predicting the litter moisture content and forecasting forest fires.

关 键 词：降雨 含水率 密实度 凋落物 

分 类 号：S762.2[农业科学—森林保护学]