Larch is the tree species most widely spread in the permafrost region of Siberia (Anonymous 1977; Dilis 1981; Koropachinskii 1983; Abaimov et al. 1997). Morphological and physiological features of the larch allowed it to adapt to severe conditions of climate, permafrost, and poor soils. The northern tree line of this species corresponds to the latitudinal timberline (Dilis 1981; Abaimov 1995). Tree-ring growth of larch at permafrost regions is characterized by features typical for the trees growing under strong influence of temperature (Vaganov et al. 1996). Dendrochronological method allows us to investigate various aspects of tree-ring formation at different locations under different conditions (Schweingruber 1996; see Chap. 17).