林业科学2020，Vol.56Issue(11)：87-96,10.DOI:10.11707/j.1001-7488.20201109
大兴安岭白桦削度方程
Stem Taper Functions for Betula platyphylla in Daxing'anling
摘要
Abstract
[Objective]Stem taper functions are important components in forest management and planning systems.Currently,there is no taper function for Betula platyphylla in northeast China,therefore,it is necessary to develop the taper function for this species.Eight commonly used taper functions in forestry were compared to evaluate which would provide a better prediction for diameter at a specific height and total volume for B.platyphylla in northeast China.[Method]The data used in this study were collected from 253 destructively felled sample trees with 3 795 diameter/height measurements in the northwest of the northern slope of Yilehuli Mountains of northeast China.A first-order continuous autoregressive error structure was used to model the error term and account for autocorrelation.Multicollinearity was also evaluated with condition number.Coefficient of determination(R2),mean absolute bias(MAB),root mean square error(RMSE)and mean percentage of bias(MPB)were selected as evaluation criteria of models.Comparison of the taper models was carried out using goodness-of-fit statistics,box plots of diameter and volume residual distributions and validation statistics.[Result]1)In terms of model fitting statistics,the models of Kozak(2004)-2,Fang et al.(2000)and Max et al.(1976)were the top three models.The model of Sharma et al.(2001)showed the poorest performance.2)Based on the box plots of diameter and volume residuals,the models of Bi(2000),Max et al.(1976),Kozak(2004)-2 and Fang et al.(2000)were more accurate in diameter and volume prediction with smaller errors and almost similar residual diameter and volume distribution.The models of Sharma et al.(2001),Sharma et al.(2004),Sharma et al.(2009)and Kozak(2004)-1 had non homogeneous distribution of the diameter residuals along different sections of the stem.3)Model validation also confirmed that Max et al.(1976),Kozak(2004)-2 and Fang et al.(2000)showed better performances. In general, the model of Kozak (2004)-2 showed consistent performances and was superior to other taper models in predicting diameter and volume. [ Conclusion ] Based on the evaluation statistics of fitting and validation, graphic analysis and condition number, the model of Kozak ( 2004)-2 was recommended for estimating diameter at a specific height, total volume and merchantable volume for B. platyphylla in northeast China.关键词
白桦/削度/材积/自相关/多重共线性Key words
Betula platyphylla/taper/volume/autocorrelation/multicollinearity分类
农业科技引用本文复制引用
Shahzad Muhammad Khurram,Hussain Amna,何培,姜立春..大兴安岭白桦削度方程[J].林业科学,2020,56(11):87-96,10.基金项目
Foundation item:National Natural Science Foundation of China(31570624) （31570624）
Applied Technology Research and Development Plan Project of Heilongjiang Province(GA19C006) （GA19C006）
Fundamental Research Funds for Central Universities. （）
