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为了对杨桦次生林下生物量模型进行补充研究,以长白山金沟岭林场杨桦次生林固定样地为研究对象,采用样地抽样的方法对林下主要树种幼树进行抽样,运用异速生长方程对幼树生物量模型进行拟合。结果表明,林下主要树种幼树生物量模型呈异速生长关系,自变量以地径D0,树高H最为紧密。其中,仅以地径D0作为单一自变量的模型精度明显低于以地径D0和树高H为自变量的模型精度;调整系数Radj2均在0.9以上,平均预测误差MPE范围在5%～49%之间,椴树的枝、叶、根和地上生物量,色木的枝生物量模型相对较差,平均预测误差均达到了40%以上;其次,根茎比与地径D0呈明显负相关关系,与树高H相关性不显著,调整系数Radj2较低,范围仅为0.053～0.507之间。最后,主要树种幼树生物量随着郁闭度的增大,表现依次下降的趋势,即W(0.6)>W(0.8)>W(1.0)。
In order to supplement the secondary biomass model of Betula platyphylla, taking the fixed sample of secondary Betula platyphylla secondary forest in Jingouling Forest Farm of Changbai Mountain as the research object, sampling samples were taken to sample young tree species of main tree species in undergrowth, Fit the sapling biomass model. The results showed that the biomass of the main tree species under the tree was allotactic growth. The independent variables were D0 and H. Among them, the accuracy of the model with D0 as the sole independent variable was significantly lower than that of the model with D0 and H as independent variables; the adjustment coefficients Radj2 were above 0.9 and the average prediction error MPE ranged from 5% to 49 %, The branch, leaf, root and aboveground biomass of Linden tree and the branch biomass model of Linmu were relatively poor, with the average prediction error reaching more than 40%. Secondly, the rhizome ratio had a significant negative correlation with the ground diameter D0 The correlation was not significant with tree height H, and the adjustment coefficient Radj2 was lower, ranging from 0.053 to 0.507. Finally, the biomass of the main tree species decreased with the increase of canopy density, ie W (0.6)> W (0.8)> W (1.0).