利用混合模型方法建立全国和区域相容性立木生物量方程

开展全国森林生物量监测和评估,建立适合较大区域范围的通用性立木生物量模型将成为必然趋势,而如何保证不同尺度范围森林生物量估计值的相容性,是必须面临的一个问题。以南方马尾松(Pinus massoniana)地上生物量数据为例,通过利用混合模型方法,同时建立全国和区域性立木生物量方程,为解决不同区域尺度范围内森林生物量估计的相容性问题提供有效途径。从模型反映的结果看,相同直径林木的地上生物量估计值随起源、地域的不同存在一定程度的差异,其差异大小可以通过混合模型中的随机效应来估计。该方法可推广应用于其它通用性模型(如材积方程)的建立。

Using Mixed-Effects Modeling Method to Establish Compatible National and Regional Single-Tree Biomass Equations

It is fundamental for monitoring and assessment of national forest biomass to develop generalized single-tree biomass models suitable for large scale forest biomass estimation. However, the compatibility of forest biomass estimates among different scales is a real problem. Based on the above-ground biomass data of Masson pine （Pinus massoniana） of southern China, the generalized single-tree biomass equations suitable for national and regional forest biomass estimation were established using mixed-effects modeling method, which provided an effective approach to solve the compatibility of forest biomass estimates among different scales. The results showed that above-ground biomass estimate of individual tree with same diameter varied in some extent among the forest origins and geographic regions, and the impacts could be estimated by random effects in the mixed model. The approach used here may be applied to construct other generalized models such as volume equations.