Models for predicting aboveground biomass of European beech (Fagus sylvatica L.) in the Czech Republic

Abstract

We developed optimal models for predicting the aboveground biomass of European beech (Fagus sylvatica L.) applicable to the national forest inventory data of the Czech Republic. The models were based on a data set of 81 beech trees collected in 19 stands that represent a wide range of stand and site conditions. The relationship between biomass and tree dimensions (diameter D, height H) was modelled using non-linear regression equations with one (D) or two (D, H) independent variables and two or three parameters (D2, DH2, DH3 models). Subsequently additional predictor variables, i.e. tree age, site index and altitude, were added to the basic models. The inclusion of tree age (T) and altitude (A) in the basic DH2 model resulted in the best model for aboveground biomass (DH2AT model). The altitude (A) and site index (S) were important predictors for stem biomass estimate (DH3AS model). Similarly, branch biomass was predicted in the best way by four-variable model DH2AS.