This study examined the effect of site and elevation on the oven-dry density and volumetric shrinkage of hornbeam （Carpinus betulus） wood. For this purpose, 45 normal hornbeam trees from three different sites （Maza...This study examined the effect of site and elevation on the oven-dry density and volumetric shrinkage of hornbeam （Carpinus betulus） wood. For this purpose, 45 normal hornbeam trees from three different sites （Mazandaran, Guilan and Golestan） at three elevations, 300 m （low elevation）, 700 m （intermediate elevation） and 1100 m （high elevation） from natural forest in northern Iran were selected. Disks were cut at breast height from mature wood and test samples were prepared to determine physical proper- ties, i.e., wood density and volumetric shrinkage. The results show that there are significant differences between site and elevation on these physical properties of wood. The interaction effects between site ~ elevation on wood density and volumetric shrinkage were also statistically significant. At any fixed site, wood density and volumetric shrinkage increased with elevation. As well, their values at Guilan were higher than those at the other two sites. The relationship between wood density and volumetric shrinkage was deter- mined by simple regression equations. Strong, positive relationships between wood density and volumetric shrinkage at each site were found. Again, these were stronger at the Guilan site than at the other two sites. Given a fixed site, the correlation at high eleva- tion was stronger than at the other two elevations.展开更多
In our investigation we studied fiber lengths and the transition age from juvenile to mature wood in Acer velutinum Boiss. For this purpose, samples from three normal maple trees at a Noshahr site in northern Iran wer...In our investigation we studied fiber lengths and the transition age from juvenile to mature wood in Acer velutinum Boiss. For this purpose, samples from three normal maple trees at a Noshahr site in northern Iran were selected. Disks were cut at breast height. Test samples were taken along a radial direction from the pith to the bark, accounting for every ring during a 48-year period. We used the Franklin method to distinguish between fibers of juvenile and mature wood. The results show that the fiber length in- creased along the radial direction from the pith to the bark. The transition age between juvenile and mature wood was determined at the 14th annual ring from the pith.展开更多
文摘This study examined the effect of site and elevation on the oven-dry density and volumetric shrinkage of hornbeam （Carpinus betulus） wood. For this purpose, 45 normal hornbeam trees from three different sites （Mazandaran, Guilan and Golestan） at three elevations, 300 m （low elevation）, 700 m （intermediate elevation） and 1100 m （high elevation） from natural forest in northern Iran were selected. Disks were cut at breast height from mature wood and test samples were prepared to determine physical proper- ties, i.e., wood density and volumetric shrinkage. The results show that there are significant differences between site and elevation on these physical properties of wood. The interaction effects between site ~ elevation on wood density and volumetric shrinkage were also statistically significant. At any fixed site, wood density and volumetric shrinkage increased with elevation. As well, their values at Guilan were higher than those at the other two sites. The relationship between wood density and volumetric shrinkage was deter- mined by simple regression equations. Strong, positive relationships between wood density and volumetric shrinkage at each site were found. Again, these were stronger at the Guilan site than at the other two sites. Given a fixed site, the correlation at high eleva- tion was stronger than at the other two elevations.
文摘In our investigation we studied fiber lengths and the transition age from juvenile to mature wood in Acer velutinum Boiss. For this purpose, samples from three normal maple trees at a Noshahr site in northern Iran were selected. Disks were cut at breast height. Test samples were taken along a radial direction from the pith to the bark, accounting for every ring during a 48-year period. We used the Franklin method to distinguish between fibers of juvenile and mature wood. The results show that the fiber length in- creased along the radial direction from the pith to the bark. The transition age between juvenile and mature wood was determined at the 14th annual ring from the pith.
