Generic models of birch (genus Betula L.) tree biomass: a meta-analysis

Due to the increase in the level of greenhouse gases in the atmosphere and climate change, an accurate assessment of biomass and carbon stocks in forest ecosystems is necessary in order to obtain reliable estimates of the deposition of atmospheric CO2 and its emissions into the atmosphere. The key method for quantifying the aboveground biomass of forest ecosystems is allometric models relating the tree biomass to the stem diameter. Since the development of biomass models based on experimental data is a time-consuming process, it is necessary to analyze existing models in order to assess their applicability in other regions. There are allometric models of biomass for different species, but their use at regional levels can be problematic due to the variability of the taxation structure of stands. Therefore, it is necessary to develop generalized (generic) models of biomass for some species or for a set of species based on meta-analysis. The purpose of this study is to develop generic models of the biomass of birch (genus Betula L.) through meta-analysis of previously published in the world literature and "recovered" meta-data of biomass in relation to the stem diameter at breast height, as well as to assess possible biases in the conditions of their local applications. Empirical data on the tree biomass and meta-data obtained by tabulating published models of biomass were used. As a result, universal models designed to assess the biomass of birch trees in a wide range of growing conditions have been constructed. The models explain 85–99 % of the variability of biomass fractions and, with multiple application, may give a slight biases (2.6 %) from the true values.