42 杉針葉外部形態の變化と個樹着生部位との関係

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1) The writer intends to investigate the variation of the form of needles of Sugi due to the position of their attaching point to an individual tree on the same stand in which his previous investigation was made on the variation of needleform in accordance with age [Jour. Jap. For. Soc. XXXI. 1-6 (1946).] and to examine the relation between them. 2) According to the results of the investigation on the form of needles due to their attaching position, it is explained that both the outside branches and inside suckers at the base of lateral branches vary their forms due to their attachment heights. But the comparison of both the form values shows that as to the same value of them, the suckers at the base of lateral branches are higher than the outside branches by 2-4 m. high. 3) The outside branch has sun leaves, but it differs in light supply between the top and the bottom. In the same manner, the inside suckers at the base of lateral branches have shade leaves, but they differ in light supply between the upper and lower part of the tree, and they seem to show the formal difference in accordance with their degrees. 4) According to the result of the graphical study of the relation between shade-and sun-leaves and their variation due to the tree age, the variation of shade-and sun-leaaes due to the height of their attachment to an individual tree is very similar to the variation curve due to the tree age, and the variation from the lower part to the upper accords with the increase and tendency of the tree age. 5) The sun-leaves of the tree top take the form at the greatest age of that tree, and accord with the form due to the age of that tree. The form of the shade-leaves in the lowest part of the tree is similar to the form which is reverse to that of the earlier age of the same tree. 6) Since outside branches≒sun leaves and inside suckers at the base of lateral branches≒shade leaves vary in their forms gradually with the height of fheir attaching point, the transition from sun leaves to shade leaves, too, is gradual. As it is inferred that sun leaves are older leaves and shade leaves younger in general, the old and young leaves in a tree grow mixedly and vary gradually. Considering this fact with regard to the whole life of a tree, it can be presumed that sahade leaves (=tolerancy) in earlier age gradually change into sun leaves (=intolerancy) as the age advances. 7) Considering the aforesaid facts referring to literatures, the writer has found that many reports have treated of the difference in form of shade-and sun-leaves and the variation of tolerance and intolerance about different trees, and only the BUESGEN'S seemes to refer summerily to the variance of the forms of shade-and sun-leaves due to tree age. 8) Examining the literature on tolerance and intolerance of other trees, the writer has found fragmental reports on such conifers as Abies, Picea, Chamaecyparis, Thujopsis, Pinus etc. But, since divers variations are recognized of such broadleaved trees as Betulaceae, Pageceae, and Ulmaceae, he keenly feels the necessity of progressing the study in this field.
一般社団法人日本森林学会の論文
1950-08-25

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