床层密实度对马尾松凋落物床层水分变化过程的影响  

Effect of Compactness of Fuelbed on Dynamic Change of Moisture Content of Litter Bed of Pinus massoniana

作　　者：兰世霞 胡兆柳 金有琪 陈芬芬 张运林 Lan Shixia;Hu Zhaoliu;JinYouqi;Chen Fenfen;Zhang Yunlin(Guizhou Education University,Guiyang 550018,P.R.China)

机构地区：[1]贵州师范学院,贵阳550018

出　　处：《东北林业大学学报》2022年第12期45-50,共6页Journal of Northeast Forestry University

基　　金：贵州省科技计划项目(黔科合基础-ZK[2021]一般158);贵州省教育厅青年科技人才成长项目(黔教合KY字[2021]251);贵州省科技支撑计划项目(黔科合支撑[2022]249);国家自然科学基金项目(31370656);贵州师范学院校级大学生科研项目(2020DXS098)。

摘　　要：对于特定的森林凋落物类型,含水率预测模型中没有考虑床层密实度且简化水分变化过程,是造成预测误差较大的原因之一。通过室内试验,得到密实度对其失水和吸水过程的影响,并建立基于床层密实度的关键参数预测模型,对于提高含水率预测精度具有重要意义。以西南林区典型林分马尾松林下凋落物为研究对象,得到不同密实度的马尾松凋落物床层在不同温湿度配比下失水和吸水过程,分析密实度对其水分变化的影响情况,并建立基于密实度的预测模型。研究结果表明:不论床层密实度如何改变,水分变化都呈指数变化,且都是前期变化速率快,后期趋于平稳;失水过程时,床层密实度对平衡含水率和失水系数都没有显著影响,吸水过程时,床层密实度对两个关键参数都有极显著影响;建立形如k=ae^(bβ)的水分变化系数预测模型,失水系数预测模型的平均相对误差为14.6%,吸水系数预测模型的平均相对误差为9.3%,均在误差可接受范围内。在今后的研究中,还需增加空气温湿度梯度,深入分析在各温湿度配比下,床层密实度对其水分动态变化的影响,为进一步提高含水率预测精度奠定基础。For specific types of forest litter,one of the reasons for the large error of the prediction model of moisture content is that the bed compactness is not considered in the model and the water change process is simplified.Through indoor experiments,the influence of compactness on its water desorption and water absorption process is obtained,and the corresponding prediction model is established.It is of great significance to improve the accuracy of prediction model of litter moisture content.Taking the litter underthe Pinus massoniana forest as the research object,and the moisture content change process of litter bed with different compactness is obtained.The influence mechanism of compactness on the dynamic change of moisture content of litter bed is analyzed,and the corresponding prediction model is established.In the air temperature and humidity range of this study,the following research results are obtained:No matter how the compactness of litter bed changes,the adsorption process and desorption process change exponentially,and the coefficient of dynamic change of moisture content is faster in the early stage and tends to be stable.In the desorption process,the compactness of litter bed has no significant effect on the equilibrium moisture content and coefficient of drying,while in the absorption process,the compactness of litter bed has a very significant effect on both parameters.The prediction model of coefficient of dynamic change of moisture content of the form k=ae^(bβ) was established,the mean relative error of the prediction models for coefficient of dying and coefficient of wetting were 14.6%and 9.3%,respectively,which were both within the acceptable range of error.In the further research,it is necessary to increase the air temperature and humidity gradient,and deeply analyze the influence of bed compactness on its water dynamic change under temperature and humidity ratio,so as to lay a foundation for further improving the prediction accuracy of moisture content.

关 键 词：密实度 凋落物 马尾松 平衡含水率 水分变化系数 

分 类 号：S762[农业科学—森林保护学]