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[目的]确定预测东北地区白桦不同高度直径和材积的最优削度方程,以弥补该地区没有白桦削度方程的不足.[方法]以伊勒呼里山北坡西北部立地亚区253株白桦伐倒木3 795对直径/高度数据为基础,基于林业上广泛应用的8个削度方程,利用SAS软件的非线性回归SUR法对方程进行拟合.使用一阶连续自回归误差结构模拟方程误差项并解释空间自相关,采用条件数评价方程多重共线性,选择确定系数(R2)、均方根误差(RMSE)、平均误差绝对值(MAB)和相对误差绝对值(MPB)作为方程评价指标,运用拟合统计量、直径和材积残差分布箱式图及检验统计量进行削度方程的综合比较.[结果]1)从各削度方程拟合统计量来看,Kozak(2004)-2、Fang等(2000)和Max等(1976)方程排在前3位,Sharma等(2001)方程表现最差;2)基于直径和材积残差分布箱式图,Kozak(2004)-2、Fang等(2000)、Max等(1976)和Bi(2000)方程在预测直径和材积时误差较小且具有相似的等方差分布,Sharma等(2001)、Sharma等(2004)、Sharma等(2009)和Kozak(2004)-1方程具有较强的方差异质性;3)模型检验证实Kozak(2004)-2、Fang等(2000)和Max等(1976)方程表现较好,Kozak(2004)-2削度方程在预测直径和材积方面表现出一致性,且优于其他削度方程.[结论]根据模型拟合和检验统计量、图形分析和条件数,Kozak(2004)-2方程被推荐用于预测东北地区白桦不同高度的直径、总材积和商品材积.“,”[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.