Height–diameter equations for larch plantations in northern and northeastern China: a comparison of the mixed-effects, quantile regression and generalized additive models
Height–diameter equations for larch plantations in northern and northeastern China: a comparison of the mixed-effects, quantile regression and generalized additive models
复制标题
DOI：
10.1093/forestry/cpw022
复制
发表时间：
2016-08
期刊：
影响因子：
2.8
通讯作者：
Hao Zang;X. Lei;W. Zeng
中科院分区：
文献类型：
--
作者：
Hao Zang;X. Lei;W. Zeng
替代方法已被用于开发树木基本和广义高径模型，包括非线性最小二乘回归，非线性混合效应方法，分位数回归（QR）和广义加性模型（GAM）。然而，这些方法还没有被彻底比较。本研究的目的是比较这些方法应用于中国北方和东北落叶松人工林的树高-直径模型。这些数据来自中国国家森林资源清查（NFI）管理的一个广泛的数据库，该数据库涵盖了广泛的林分分布和林分条件，包括342个样地的5684对高度和直径。随机效应在省，物种和地块水平，并结合省和物种的基本和广义H-D模型。结果表明，混合效应基本模型的拟合和验证效果最好; QR模型可以代表不同分位数下的H-D关系，GAM模型适合于H-D关系的非线性建模，特别是广义H-D模型。这一发现表明，混合效应基本模型不需要额外的变量，是一个足够的工具，用于产生缺失的高度测量在北方和东北落叶松人工林。
Alternative methods have been used for developing tree basic and generalized height – diameter models, including non-linear least-squares regression, non-linear mixed-effects method, quantile regression (QR) and a generalized additive model (GAM). However, these approaches have not been thoroughly compared. The purpose of this study was to compare these methods applied to tree height – diameter models for larch plantations in northern and northeastern China. The data were obtained from an extensive database curated by the China National Forest Inventory (NFI) that covers a wide distribution and range of stand conditions, including 5684 paired heights and diameters in 342 plots. Random effects at the Province, species and plot levels, and a combination of Province and species into the basic and generalized H – D models were incorporated. This study demonstrated that the mixed-effects basic model provided the best performance for model fi tting and validation; QR could represent variable H – D relationships at different quantiles and the GAM was a suitable alternative for fl exible modelling of the H – D relationship, especially for generalized H – D model. This fi nding indicates that the mixed-effects basic model does not require additional variables and is an adequate tool for generating missing height measurements for larch plantations in northern and northeastern China.