长白山林区14种幼树生物量估测模型

以长白山林区林下14种幼树为对象,采用收获法对胸径D1.3≤2.5cm的幼树植株进行随机取样,通过对不同树种各器官和全株生物量的统计,建立了幼树生物量的最优估测模型,并进行了实测验证。结果表明:以地径(D0)和地径平方与株高乘积(D20H)为自变量,拟合的14种幼树各器官和全株生物量最优模型为幂函数,并达到了极显著水平,而且都有较大的R2值(0.712～0.983)和较小的SEE值(0.217～1.122)。幼树器官和全株生物量最优回归方程的R2值,从大到小依次为全株生物量地上部分枝地下部分叶。验证结果表明:以地径(D0)为自变量时,建立的幼树器官和全株生物量模型,对生物量的估测结果均较为准确。自变量为地径平方与株高乘积(D20H)时,怀槐、东北槭等8种幼树器官和全株生物量模型对生物量预测效果较好;除红松、拧筋槭等6种幼树部分器官和全株生物量模型估测效果相对较差外,其他模型均可对生物量进行准确估测。

Biomass estimating models of saplings for 14 species in Changbaishan Mountains, northeastern China

Randomly sampling saplings with D _1.3≤2.5 cm for 14 species in the Changbaishan Mountains region of northeastern China, we established and validated organs and whole plant biomass models for each of the 14 species. It was found that sapling organs and whole plant biomass can be modeled accurately by the power function when ground diameter (D0) or the product of ground diameter and height (D²₀H) taken as the independent variables. The correlation coefficient R₂ ranged between 0.712 and 0.983 and SEE(standard error of the estimate) was lower (0.217-1.122). With respect to estimation accuracy and taking R₂ as the fitting statistics, sapling organs and whole plant biomass models were in the following descending accuracy order：whole plant biomass>aboveground biomass>branch biomass>underground biomass>leaf biomass. It is validated that the fitted models can give accurate estimates for sapling organs and plant biomass when ground diameter taken as the independent variable. However, using the product of ground diameter and height as the independent variable, the fitted models yield accurate estimates only for 8 species saplings such as Amorpha fruticosa, Acer mandshuricum, etc., but not for some organs or whole plant biomass for the other 6 species，such as Pinus koraiensis and Acer triflorum，etc.