JOURNAL OF NANJING FORESTRY UNIVERSITY ›› 1958, Vol. 1 ›› Issue (01): 62-67.doi: 10.3969/j.jssn.1000-2006.1958.01.008

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TWINING HABIT OF WOODY LIANAS AND THEIR INJURIOUS EFFECTS ON THE SUPPORTING TREES

Hsiung Wen-Yue   

  • Online:1958-03-18 Published:1958-02-18

Abstract: This decription is mainly based on field observations mostly made in some forests in Kiangsu, Kiangsi, Fukien and Kwangtung provinces during the past few years. Lianas mentioned in this paper are woody plants. Thr twining habit and effects on suporting trees have benn discussed in some betail.In the course of development woody lianas iffer gtreatly in their growth forms. A woody twiner, arising either from seed or from root or stump, grows erectly without any support in first few years and then starts twisting and revolving spontaneously as its length increases. In such a manner a support can be found, and consequently twining occurs. The twining climber rapidly runs up the supporting tree on which it spreads its luxuriant shoots and foliage. Presumably twining habit is an adaptation of lianas as regards light.All the twiners twist in the same direction with the twining move Ment. These movements influence and benefit each other. In that portion of a twining stem where twisting is exceptionally frequent, the revolution is accelerated, and the spiral angle formed becomes narrow. Consequently twining stem becomes tightly attached to a support, the damage caused is serious.The addition of the wieght of lianas to their supports usually bends the crown to all sides and causes various deformations of the supporting trees. As result of growth twining becomes so tightened that the trunk of the supporting tree is engraved with a beep spiral furrow and that the descending flow of organic substances is interfered by constriction of the ploem. The tree encircled subsequently arranges its new conductive elements parallel to, the spiral course that the translocation of nutrient materials upward and of organic substances downward may continue. The orientation of new tissue, is slowly developnd that the conductive efficiency is greatly reduced. Consequently the organic substances accumulate in the region just above the point where the twinerwinds atound and result in swollen portions along the trunk. In some cases the twiner adhers to its Support so tightly that the tree stem embraces it in the course of growth. This curiosity may be seen in the cross or longitudinal section of the encircled tree.