A Comparison of Hierarchical and Non-Hierarchical Bayesian Approaches for Fitting Allometric Larch (Larix.spp.) Biomass Equations

Dongsheng Chen,Xingzhao Huang,Xiaomei Sun,Wu Ma,Shougong Zhang

doi:10.3390/f7010018

Dongsheng Chen, Xingzhao Huang + Show 3 more

Open Access

https://doi.org/10.3390/f7010018

Copy DOI

Abstract

Accurate biomass estimations are important for assessing and monitoring forest carbon storage. Bayesian theory has been widely applied to tree biomass models. Recently, a hierarchical Bayesian approach has received increasing attention for improving biomass models. In this study, tree biomass data were obtained by sampling 310 trees from 209 permanent sample plots from larch plantations in six regions across China. Non-hierarchical and hierarchical Bayesian approaches were used to model allometric biomass equations. We found that the total, root, stem wood, stem bark, branch and foliage biomass model relationships were statistically significant (p-values < 0.001) for both the non-hierarchical and hierarchical Bayesian approaches, but the hierarchical Bayesian approach increased the goodness-of-fit statistics over the non-hierarchical Bayesian approach. The R2 values of the hierarchical approach were higher than those of the non-hierarchical approach by 0.008, 0.018, 0.020, 0.003, 0.088 and 0.116 for the total tree, root, stem wood, stem bark, branch and foliage models, respectively. The hierarchical Bayesian approach significantly improved the accuracy of the biomass model (except for the stem bark) and can reflect regional differences by using random parameters to improve the regional scale model accuracy.

Highlights

Larch (Larixspp.) is a commercially valuable timber that is widely planted in the mountains of North, Northeast and Southwest China because of its straight shape and high resistance to bending and cracking
We found that the hierarchical approach performed better, and the hierarchical Bayesian approach significantly improved the accuracy of the biomass model, except for the stem bark model
The larch biomass data were collected from different regions, including Hubei, Gansu, Hebei, Liaoning, Heilongjiang and Inner Mongolia, which encompass large climate, larch species, silviculture and stand density variations that affect biomass accumulation

Summary

Introduction

Larch (Larixspp.) is a commercially valuable timber that is widely planted in the mountains of North, Northeast and Southwest China because of its straight shape and high resistance to bending and cracking. China contains the largest area of larch plantations in the world [1]. The plantation biomass and carbon sequestration calculations have been studied by numerous researchers [2,3,4]. The calculations are a prerequisite for understanding carbon pool dynamics in plantations. The biomass and diameter data sets are typically collected from sample plots in the field. This technique is generally destructive, Forests2016, 7, 0000; doi:10.3390/

Methods

Results

Discussion

Conclusion