摘要
通过对山西省方山县不同密度人工白榆林（Ulmus pumila）5～10月典型晴天净辐射（Rn）在林冠内垂直分布的实测资料分析,根据Beer Lambert方程,结合林分生长季内的叶面积指数（LAI）动态变化,研究了密度为1.5m×2 m和1.5 m×4 m的白榆林消光系数的日变化过程和季变化过程,同时对影响消光系数的因素进行分析。结果表明：消光系数的日变化过程主要受太阳高度角的影响,而季变化过程主要受叶面积指数的影响;密度对消光系数的影响主要是通过对林冠结构的调整而实现的。
Based on the data of forest-elm in different density about the net radiation＇s distribution and canopy structure measured in Fangshan, Shanxi Province, and accounting to Beer Lambert＇ equation and considering the dynamic change of the leaf areas index （LAI） ,the paper selected the density in 1.5 m×2 m and 1.5 m×4 m forest-elm on study, researched the changing process of extinction coefficient in a day and in a growing season, at same time analyzed the factors affecting the extinction coefficient. The result showed that, the changing process of extinction coefficient in a day mainly affected by solar altitude, while the changing process of extinction coefficient in a growing season mainly affected by leaf areas index（LAI） ; and the effect of density to the changing process of extinction coefficient is carried out by modulating the structure of canopy,
出处
《水土保持研究》
CSCD
北大核心
2007年第4期340-342,共3页
Research of Soil and Water Conservation
基金
教育部科学技术研究重大项目“北方退耕还林区水土保持植被恢复与重建技术研究”（10407）
国家自然科学基金“黄土半干旱区防护林树种耗水特性及其水分环境容量研究”（30371172）.
关键词
净辐射
叶面积指数
消光系数
net radiation
leaf areas index
extinction coefficient
