Abstract:

The differences in wood density, MOR, MOE and crushing strength, the radial variation pattems of wood density and the relationships between mechanical properties and wood density among different heights and four cardinal sides within 15 Chinese-fir trees from Zhejiang province were determined and analysed.There were significant differences in MOR and MOE but no significant ones in wood density and crushing strength among different heights.The mechanical properties and wood density in northern and southem sides were higher than thos in eastem and western sides, however, the differences were insignificant.The density profiles at different heights and in different cardinal sides were horizontal straight lines with fluctuation within 0.1 g/cm³.There were significant correlations between mechanical properties and wood density at different heights and different cardinal sides.The correlation coefficients were greater in southem and eastern sides than in northern and western sides with larger variation in the correlations of MOR and MOE to wood density.

Key words: Mechanical properties, Wood density, Variation within trees