| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1989: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1988: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Research Abstract |
Wood anatomical characteristics, namely; fiber length, vessel element length, diameter and distribution of pore, and density and their variations between samples with different growth rates from same aged Anthocephalus chinensis, Gmelina arborea and Eucalyptus saligna were examined.
Fiber length became more or less stable at the distance of 5-9 cm from the pith, regardless of species, age and diameter. Fiber length increased rapidly at first toward the bark, and then, became more or less stable at a certain distance from the pith: at 8 to 9 cm from the pith in Anthocephalus chinensis, 6 to 7 cm in Gmelina arborea and 4 to 5 cm in Eucalyptus saligna.
Up to a certain distance from the pith, the increasing rate of vessel element length was greater in trees of small diameter than those of large diameter, especially in Anthocephaliis chinensis. However, in all Eucalyptus saligna trees, the vessel element length was with the length of the same increasing rate, and moreover, the length was simi
… More
lar in trees of all stem diameters.
Pore density was highest (22 to 24 per square millimeter) near the pith, decreased rapidly from the pith 1 to 2 cm outward, then became constant. But pore density at shorter radius was higher than at longer radius in Gmelina arborea. Pore density decreased outward from 4 to 6 per, square millimeter at 5 to 7 em from the pith and became more or less constant. Pore density in Anthocephalus chinensis and Eucalyptus saligna showed the same tendency as in Gmelina arborea. Pore density in outer part of Eucalyptus saligna was ten per square millimeter, which was greater than in the other two species.
Ratio of ray became a constant 10 to 12 cm from the pith in large diameter stem of Gmelina arborea and 7 to 8 cm from the pith in small diameter stem. This position was at about 80 percent relative distance at longer radius of all specimens from Gmelina arborea. Ratio of ray in large-diameter trees was greater than in small-diameter trees. Ratio of ray is considered to be closely related to growth.
Average specific gravity was 0.47, 0.58 and 0.59 in large, medium and small diametelstems, respectively, in Eucalyptus saligna. Specific gravity was higher in small-diameter stems than in large ones, especially in Eucalyptus saligna. Less
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