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Báo cáo khoa học: "Tension wood and growth stress induced by artificial inclination in Liriodendron tulipifera Linn. and Prunus spachiana Kitamura f. ascendens Kitamura"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Tension wood and growth stress induced by artificial inclination in Liriodendron tulipifera Linn. and Prunus spachiana Kitamura f. ascendens Kitamura. | 739 Ann. For. Sci. 57 2000 739-746 INRA EDP Sciences Original article Tension wood and growth stress induced by artificial inclination in Liriodendron tulipifera Linn. and Prunus spachiana Kitamura f. ascendens Kitamura Masato Yoshida Tomonobu Okuda and Takashi Okuyama Laboratory of Bio-Material Physics Graduate School of Bioagricultural Sciences Nagoya University Nagoya 464-8601 Japan Received 19 July 1999 accepted 28 February 2000 Abstract - The relationship between the amount of growth stress and the degree of artificial inclination was investigated in saplings of two angiosperm species. The tensile growth stresses generated in Prunus spachiana which forms gelatinous fibers were larger than those in Liriodendron tulipifera which does not form gelatinous fibers. In both species the tensile growth stresses generated in the upper side of inclined stems increased and the cellulose microfibrillar angle decreased proportionally as the inclination changed from 0 vertical to 20 . At inclinations over 20 the tensile growth stress and cellulose microfibrillar angle did not change further. The thickness of the current growth layer increased linearly with the angle of inclination but eccentric growth was not the main factor contributing to the upward bending moment to return the axis to the normal vertical position. This paper reveals that the growth stress generated by inclination is limited. That is growth stress increases with the inclination angle to a point but then does not increase further. artificial inclination tensile growth stress tension wood Prunus spachiana Kitamura f. ascendens Kitamura Liriodendron tulipifera Linn. Résumé - Bois de tension et contrainte de croissance induits par inclinaison artificielle chez Liriodendron tulipifera Linn. et Prunus spachiana Kitamura f. ascendens Kitamura. La relation entre la contrainte de croissance et le niveau d inclinaison artifi-cielle a été étudiée sur des pousses de deux espèces angiospermes. La contrainte de .