The Relationship Between Variability of Cell Wall Mass of Earlywood and Latewood Tracheids in Larch Tree-Rings, the Rate of Tree-Ring Growth and Climatic Changes

Summary Mass accumulation dynamics in earlywood and latewood cell walls of larch from northern regions of Central Siberia are investigated and correlations among cell mass of different tree-ring zones, radial tracheid sizes and tree-ring width are found. A linear relationship exists between cell wall mass and radial cell size. The deviation of cell mass from the regression line (index of mass deviation) and the mean density of the respective tree-ring zone are similarly functionally dependent on the radial cell size and reflect the realization of the potential determined during the period of cell formation. There is a critical value of larch tree-ring width in relation to cell mass. For the treerings with width less than this critical value the difference in the mass of earlywood and latewood cells increases with decreasing tree-ring width. The cell wall mass correlates with the monthly temperatures of June and July. Under favorable growing conditions tracheids with similar mass of cell walls are formed in earlywood and latewood, while under unfavorable conditions cell wall mass accumulation in latewood is severly limited. A comparative analysis of the cell wall mass in earlywood and latewood indicates that mass accumulation is independent of the switching processes from earlywood production to the production of latewood.