Biomass Expansion Factors (BEFs) and Carbon Stock for Brant's Oak (Quercus brantii Lindl.) Forests in West-Iran

Investigating a tree’s biomass can provide basic information about forest carbon stock. The Biomass Expansion Factor (BEF) is a variable for estimating carbon stock of forests. The aim of this study was to analyse the Above Ground Biomass (AGB) allocation, developing the BEF and carbon stock for two vegetation forms of Brant’s Oak ( Quercus brantii Lindl.) based on forest inventory data. BEF is defined as the ratio of AGB to crown volume variables. The study data were taken from 30 trees that include 16 individual trees with single stem and 14 coppice shoots located in West-Iran. The trees selected were felled and separated into different components including: bole, main branches, lateral branches, twigs and leaves. The fresh weight of the trees was obtained with a portable hanging scale and several samples were taken from each tree component. The results of this study showed significant differences between component biomass proportions of the two vegetation forms of Brant’s Oak trees and determined average biomass and carbon content of the forms studied. We also conclude that BEF of Brant’s Oak could be improved by applying crown variables. According to the results, BEFs are tree-size dependent variables. Finally, this study indicates that age-dependent BEFs cannot be applied to conditions where stand development deviates from the conditions that in which the BEFs were developed.