Assessment of Mixed Forest Stand Biomass in Kamchatka Using Tree-Rings

In this study, the results of tree-ring based biomass reconstruction as well as carbon uptake of Kamchatka forest stands are presented. Up till now, there are no biomass instrumental measurements available for the Kamchatka Peninsula that could be used to develop species-specific regional allometric models. The problem of lack of data was solved by using measurement series from nearby areas (Magadan oblast and the Sikhote-Alin Mountains). The biomass reconstruction is based on the tree-ring width chronologies of poplar, birch, larch and trunk diameters measured in the field. The results show that the biomass variation is determined by two parameters: summer air temperatures variations and the anthropogenic factor. Positive response of all tree-ring width chronologies to summer air temperatures is strong evidence of the contribution of this parameter to the variability of biomass. It was found that the relationship between biomass and temperature weakened in the 1940s and 1960s, when the recorded vast logging and fires in the area of the Esso settlement led to an increase in tree growth due to an increase in light availability. The reconstructed biomass and net primary production series almost completely coincide for a whole common 22-year period. Considering that both series were obtained by independent methods — based on the tree-ring width and remote sensing data, the tree-ring based biomass reconstruction is highly reliable. Short series of net primary production data obtained from remote sensing do not allow us to assess past long-term changes, since it covers only the last decades, while the tree-rings can provide the biomass estimate for several centuries.

dendrochronology, Kamchatka, biomass, climatic response function, net primary production, remote sensing data, MODIS