ANATOMICAL CHARACTERISTICS AND MECHANICAL PROPERTIES OF LARIX SIBIRICA GROWN IN SOUTH-CENTRAL SIBERIA

Tracheid length, microfibril angle, spiral grain, wood density, MOE, MOR, compressive strength, modulus of rigidity and their inter-relationships were investigated for fifty Siberian larch trees (Larix sibirica) collected from five natural stands. No inter-stand variation in tracheid length, microfibril angle and spiral grain was observed. No effect of tracheid length and microfibril angle on the mechanical properties was observed. Inter-stand variation in wood density was significant, especially for mature wood. The wood from the Baikal site in the eastern range of the natural distribution had a very high density. The wood from the Altai site in the mountain range had a low density, especially within the latewood. Minimum density within a ring seemed to be the major source of variation for average density within the heartwood, whereas the effect of maximum density on average density was greater within the sapwood. Wood density, which was much higher for a given ring width than in plantation-grown Japanese larch (Larix kaempferi), had a major effect on the mechanical properties.