Parameterisation of allometric equations for quantifying aboveground biomass of Norway spruce (Picea abies (L.) H. Karst.) in the Czech Republic

Abstract

The aim of the present study was to develop allometric equations for predicting aboveground biomass of Norway spruce (Picea abies (Linnaeus) H. Karsten) applicable to the typically managed spruce forest on acidic and nutrient-medium sites in the Czech Republic. The models were based on an extensive data set of 139 spruce trees collected in 25 stands on 15 sites. The biomass in dry mass was modelled using linear regression equations with one (diameter at breast height-D), two (D, slenderness ratio-H/D) or three (D, H/D, site index-SI, or tree age-A) predictors. The models were validated using the leave-one-out method. The value of the root mean square error of cross-validation was chosen as the main criterion for the best-model selection. Both the total aboveground biomass and stem biomass were best predicted by three-variable models (D, H/D, SI). For crown and foliage biomass the simple one-variable model (D) is recommended.