辽东山区日本落叶松生物量相容性模型的研究

Compatible Biomass Models for Larix kaempferi in Mountainous Area of Eastern Liaoning

基于60株辽东山区日本落叶松样木生物量的实测数据,分析不同林龄条件下立木各部分生物量的变化情况,并应用度量误差方法建立立木相容性生物量模型。结果表明:树叶、树枝、树皮生物量占总生物量的比值随林龄增长呈下降趋势,干材占总生物量的比值随林龄增长呈上升趋势。在筛选出总生物量与各分量最优独立模型的基础上,应用三级控制的方法建立生物量相容性模型,并采用加权回归方法消除总量和各分量模型的异方差。建立的总量、地上部分、树干、干材、树皮生物量模型,其R2均大于0.9;树根、树冠、树叶和树枝生物量的R2略低,介于0.7 0.9之间。通过独立样本对模型的相容性和预测精度进行检验,各分量预测值所占总生物量的百分比之和为1,模型完全相容;根、冠、叶和枝的模型预测精度略低于90%,其他部位模型的预测精度都在95%以上,模型的预测精度较高。

Based on the biomass data of 60 sampling trees of Larix kaempferi in mountainous area of eastern Liaoning Province,the biomass of each component with different ages was analyzed.The compatible models for the biomass of whole tree and each component were established using non-linear error-in-variable modeling method.The results showed that the biomass ratio of needle,branch and bark dropped with stand age growth,but that of stem rose up with stand age growth.Based on the optimal model,the compatible models for whole tree,biomass and each component were established by three-step control programs,and the heteroscedasticity of the models for whole tree and components was eliminated with weighted regression.The determination coefficients of whole tree,above-ground,trunk,stem and bark biomass were higher than 0.9.The determination coefficients of root,crown,foliage and branch ranged from 0.7 to 0.9.From the model tested by independent samples,the sum of each component ratio was 1 and the model was totally compatible.The prediction precisions of root,crown,needle and branch were less than 90％,but the others were higher than 95％.