基于树冠形态特征因子的云南红豆杉单木生物量模型拟合

Single Tree Biomass Simulation of Taxus yunnanensis Plantation Based on Crown Morphological Index

以3年生福建省明溪县云南红豆杉原料林为研究对象,以地径、树高为基础自变量,导入冠幅、冠形率、树冠率等树冠形态特征自变量,用逐步回归的方法优选系列单木生物量理想数学模型。采用独立样本的检验方法,对优选模型进行t检验与偏差检验,估算预测精度。结果表明:导入树冠形态特征自变量后明显提高单木生物量模型的判定系数,且模型较未导入树冠形态特征有着更好偏差与预测精度表现。树冠形态结构显著影响红豆杉单株生物量;冠幅和冠形率明显促进枝叶生物量、茎干生物量、地上生物量,树冠率、冠幅明显促进红豆杉总生物量。在系列红豆杉单木模型导入树冠形态特征因子是必要的,可提高系列生物量模型的预测效果。系列优选的生物量模型均通过t检验、偏差检验,模型的预测精度均在92.36%以上,可以用于生产中的生物量预测。

Taking 3-year-old Taxus yunnanensis raw material forest as research object, based on the independent variables of ground diameter and tree height, the independent variables of crown morphological characteristics such as crown width, crown shape rate and crown ratio were introduced, and a series ideal mathematical models of single tree biomass were optimized by stepwise regression method. The t-test, deviation test and precision estimation were carried out on the optimal biomass model of T. yunnanensis by using the independent samples test method. The results showed that the decision coefficient of those single tree biomass modeles was obviously higher after introducted the independent variables of crown morphological characteristics, and the model has better deviation and prediction accuracy than that of crown morphological index unrelated. The crown morphological structure significantly effected the single plant biomass of T. yunnanensis. The crown width and crown shape rate have significant effected on the branches and leaves biomass, stem biomass and aboveground biomass,the crown rate and crown width could significantly promote the total biomass. It is necessary to introduce canopy morphological characteristics factors into those single tree biomass models of T. yunnanensis, which can improve the prediction accuracy. Those optimal biomass models passed the t-test and the deviation test, those optimal models prediction accuracy was above 92.36%, which can be used to predict biomass in production.