The Wood Anatomical And Physico-Mechanical Properties Of Eucalyptus Urophylla×Eucalyptus Grandis

The indexes of the anatomical properties and the major physico-mechanical properties and the relationship in wood properties of E.urophylla×E.grandis from eight families(DH2, DH12, DH16, DH18, DH19, DH30, DH32 and DH33) and three clones(DH30-1, DH30-5 and DH30-7) in Guangxi-Dongmen Forest Farm have been studied systematically through experiments. Then the obtained data has been analyzed and discussed in details based on the theories of wood anatomy, wood physics and wood mechanics by means of mathematical statistics to seek the variation regularities of growth traits and wood properties of plantation E.urophylla×E.grandis. The results are as follows:(1) Radial variance of the anatomical properties: From pith outward, the fiber length and the ratio of fiber length to width of plantation E.urophylla×E.grandis wood increase by year, reach maximum at certain age, and then level off, mostly fluctuate above or below a axis; The variance regulation of the fiber width is similar to that of the fiber length, only the fluctuation of the fiber width is less than that of the fiber length; The double wall thickness and the double wall thickness to diameter ratio increase or decrease in great fluctuation with the age increasing; The fiber diameter to width ratio and the microfibrilla angle decrease gradually showing a gentle trend; The vessel-elements proportion also increases or decreases in great fluctuation with the age increasing firstly, reaching the maximum value at 5th annual ring, and then decreases gradually; The fiber proportion increases or decreases in fluctuation with the age increasing; The ray proportion decreases by year, reaches the minimum at certain age and then, increases gradually; While the axial parenchyma proportion hardly takes on great fluctuation and has no certain regulation along the radial orientation.(2) The average fiber length of plantation E.urophylla×E.grandis wood is between 800 and 1100 micro, which is suitable for paper industry. And the widely individual distribution of the fiber length provides the probability of improving it. The conic equation between the fiber length and annual ring is superior to cubic curve equation.(3) Axial variance of the physical and mechanical properties: The basic density has a high value at the base part in common. From the base upward, the basic density decreases gradually, reaches the minimum value at the middle part and then rises with...