A single-tree additive biomass model of Quercus variabilis Blume forests in North China

Abstract

Key message Fitting and comparing three sets of compatible biomass models for prediction of biomass or carbon stocks of natural and planted Quercus variabilis Blume forests.Abstract To make the sum of estimated values from biomass models of various components of a tree equal to estimated tree total biomass for Quercus variabilis Blume (cork oak) forests in North China, single-tree compatible biomass models were developed. 100 trees from 100 plots in North China were felled to obtain biomass of aboveground components, and roots of 19 of those trees were extracted for measurement of root biomass. After Box-Cox transformations of variables, two sets of independent component biomass models with a dummy variable in models to define stand origin were separately built using linear mixed effects analyses (one set of models with site as a random factor; the other set without any random factor). Then three methods were compared to force compatibility of the biomass models: sums of linear mixed effects models, sums of linear models, and simultaneous equation fits based on linear models. Model parameters were estimated by ordinary least squares (OLS) or seeming unrelated regression procedures (SUR). Coefficients of determination (r 2 ), root mean square error (Rmse), residuals plots and histograms of residuals indicated that models fitted with sums of linear mixed effects models were the least biased and most precise at estimating total above-ground biomass.Further testing for the linear mixed effects models with jackknife validation and prediction sum of squares (PRESS) statistics indicated that the compatible biomass models can be used to predict biomass or carbon stocks of cork oak forests in North China within specific tree diameter at breast height and height ranges.

Mathematical and ecological traits of above and belowground biomass production of beech (Fagus silvatica L.) trees growing in pure even-aged stands in north-east France

“…Considering that the ecophysiological studies, especially the analysis of the links between tree growth and environmental factors, conducted in this forest could be extended to younger or older stands, it would be of interest to develop generalized biomass equations that could apply to all the age range of the classical beech rotation (0-120 years), avoiding the need to build new specific biomass equations. Such models were successfully developed earlier by introducing different tree characteristics in the biomass equations, and in particular tree height (ht) often combined with tree diameter 1 (d) in the form of d 2 ht , or more generally d α ht β (Genet & al, 2011a, b;Shaiek & al, 2011;McElligott & Bragg, 2013;Sileshi, 2014;Zheng & al, 2015).…”

“…The biomass and biomass increment equations previously established in Hesse forest were fitted independently for each tree compartment and for the aboveground and belowground compartments, each one taken as a whole. Thus, the constraint of additivity for the tree compartments composing either the aerial or the belowground tree parts was not considered at that time, although it would have been desirable (Repola, 2008(Repola, , 2009Genet & al, 2011a;Parresol, 2011;Zheng & al, 2015).…”

Developing Aboveground Biomass Equations Both Compatible with Tree Volume Equations and Additive Systems for Single-Trees in Poplar Plantations in Jiangsu Province, China

“…Considering additivity within a system of biomass equations can ensure consistency among the components [37][38][39]. In this study, the process of additivity was realized with the nonlinear error-in-variable models and by applying a "controlling directly under total biomass by proportion function" approach.…”

Models for Predicting the Biomass of Cunninghamialanceolata Trees and Stands in Southeastern China

“…The use of the tree volume taken from forest management data to calculate the bi of different species is very important for estimates at different scales [35]. The relationship between the new parameter bi and other stand indicators still requires further detailed study [36]. …”