基于两种冠层分析仪的桉树叶面积指数测算

Development of Regression Models for Determining Eucalyptus LAI from Two Canopy Analyzers

以13个月生的尾巨桉林分为研究对象,对比了HemiView和TRAC两种冠层分析仪在测定叶面积指数时相对于实际测定的叶面积指数的差异,结果显示HemiView测定值<TRAC测定值<实测值,并分别对两种冠层分析仪的测定结果与实际测定结果进行回归分析和模型验证,得出二次曲线为最好的回归模型,二者的回归模型分别为y=7.988-14.547 x+8.338 x2和y=4.613-5.101 x+2.192 x2,拟合度分别为0.952和0.973。

This study examined crowns of a 13 month old Eucalyptus urophylla × E. grandis clone to examine the relationships between LAI estimates obtained using HemiView and TRAC canopy analyzers and the results of actual direct leaf area measurements. The results showed that the estimate obtained using HemiView〈the estimate obtained using TRAC〈the actual leaf area measurement. Each of the two canopy analyzer determination results were used for regression analysis and model verification with the results of actual leaf area measurements. A quadratic regression provided the best fit, and the models obtained were y=7.988-14.547 x＋8.338 x2 for HemiView;and, y=4.613-5.101 x＋2.192 x2 for TRAC, with the goodness of fit for these models being 0.952 and 0.973 respectively.