华北落叶松人工林叶面积指数实测值与冠层分析仪读数值的比较和动态校正  

The Comparison and Dynamic Calibration between the LAI Values of a Larix principis-rupprechtii Plantation Determined by Canopy Scanner and Litter-fall Collection

作　　者：郝佳[1] 熊伟[1] 王彦辉[1] 于澎涛[1] 刘延惠[1] 徐丽宏[1] 王轶浩[1] 张晓蓓[2] 

机构地区：[1]中国林业科学研究院森林生态环境与保护研究所,北京100091 [2]河北农业大学林学院,河北保定071000

出　　处：《林业科学研究》2012年第2期231-235,共5页Forest Research

基　　金：林业公益性行业科研专项(201104005-02;200904056;200904005);国家自然科学基金项目(40730631;41071023);"十二五"国家科技计划课题(2011BAD38B05);中国森林生态系统定位研究网络(CFERN)宁夏六盘山森林生态定位站和国家林业局森林生态环境重点实验室资助

摘　　要：叶面积指数（LAI）是森林生态系统的重要结构参数,用来反映植物叶量和群体生长特征,对生态系统水分和养分循环、地表和大气之间的相互作用等诸多过程都有重要影响,广泛应用于植物生态、植物生理、生态水文以及一些交叉学科的研究中,也可作为科学培育森林、In order to test the accuracy of the usually-used fixed calibration factor of the canopy scanner of LAI-2000 for measuring the leaf area index（LAI）,a Larix principis-rupprechtii plantation was chosen in the small watershed of Xiangshuihe located at the Liupan Mountains of Ningxia Hui Autonomous Region of NW China,the LAI was measured in October 2010,a period from full canopy to the total fall of needles,by using both the LAI-2000 and litter-fall collection method.Then,a comparison was made between the LAI values determined by the litter-fall collection and that calculated based on the figures read from LAI-2000 and the fixed calibration factor（1.49）.It showed that the average of LAI measurements of the 2 methods was very close,with a difference of only 5%.However,the calculated LAI from LAI-2000 was obviously higher than the true values determined by litter-fall collection when the canopy was full of needles;and obviously lower than the true value when the canopy was sparse after needle falling.The reason may be that LAI-2000 takes the projection of twigs as needles.So,a dynamic calibration factor is needed,especially in the seasons when the needle amount and the percentage of twigs projection in crown projection change quickly.Therefore,a statistic relation in a quadratic polynomial form between the 2 series of LAI data was well fitted.This relation can be used for a more accurate estimation of LAI based on the data read from the easily-used canopy scanners like LAI-2000.

关 键 词：华北落叶松 叶面积指数 LAI-2000 调落物收集 校正系数 

分 类 号：S791.22[农业科学—林木遗传育种]