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No.12 (1965/10) >

Title  :  樹木の偏椅成長について成長錐挿入方向の検討 
Title alternative  :  Eccentric growth of trees. A study of the inserting direction of the increment borer at breast height of stems. 
Authors  :  砂川, 季昭 平田, 永二 
Authors alternative  :  Sunakawa, Sueaki Hirata, Eiji 
Issue Date  :  1Oct1965 
Abstract  :  This research was done in order to determine the inserting direction of the increment borer at breast height of stems by investigating eccentric growth of trees. The results of the research are follows: 1. Eccentric growth of the diameter at breast height; 1) The range and the mean of the eccentric growth percentage, which is expressed as the percentage of the difference between the maximum and the minimum diameter to the maximum, are from 4% to 16%, and 7.4% respectively. 2) On individual tree, the eccentric growth of the diameter at breast height is mainly caused by the condition of branching and the inclination of the forest land. In the direction of the contour, the eccentric growth is not recognized. 3) As a whole, the percentage of the eccentric growth is found to be 2% in the total value of samples. 4) There is no significant difference in diameter at various direction. 5) It is resumed that the measurement of the diameter at breast height may be pertinent at any direction from the result stated in the above 3) and 4). 2. Eccentric growth in the length from the pith to the cambium; 1) The eccentric growth percentage from the pith, which is expressed as the percentage of the difference between the maximum and the minimum radius excluding the thickness of the bark to the maximum, ranges from 10% to 55%, while the mean of samples is 28.9%. 2) On the individual tree, it is presumed that the eccentric growth occurs to the direction of the wind and the inclination of the forest land. 3) The eccentric growth percentage from the pith in total value of samples is 11%. 4) From the analysis of variance, it is found the eccentric growth from the pith is not significantly affected by the direction. 5) Although the maximum value of the eccentric growth from the pith reaches 55% with a extreme sample, the difference of the eccentric growth from the pith become smaller when may sample are averaged and the significant difference is not found. There is, therefore, no necessity to be particula.r about the inserting direction of the increment borer. 3. Core length; 1) The percentage of the difference between the maximum and the minimum core length to the maximum ranges from 13% to 40%, and the mean is 24.4%. 2) In regard to individual tree, the core length is longest in the west side of the tree and shortest in the direction of the descent. 3) The percentage of the difference between the maximum and the minimum core length to the maximum in the value of total samples is 3%. 4) According to the result of the analysis of variance, there is no significant difference in the core length of respective directions. 5) Significant difference between the core length in recent five years and the true growth measured by a disk at breast height is not recognized in the respective directions. 6) It may be reasonable to think that there is no propare direction for the insertion of the increment borer from the statement of the above 3), 4) and 5). 4. Diameter growth; 1) The percentage of the difference between the maximum and the minimum of the diameter growth to the maximum ranges from 5% to 40%, and the mean of samples is 22.1%. 2) In each sample tree, the maximum value of the diameter growth in recent five years is highest in frequency at the east side of the tree, but lowest in the direction with the longest branch. 3) As a whole, the percentage of the difference between the largest diameter growth and the smallest to the largest is about 4%. 4) It is found that the diameter growth, which is measured by using the increment borer, is not significantly affected by the direction from the result of the analysis of variance. 5) It may be not necessary to be particular about the inserting direction in case of investigating the diameter growth with the increment borer as mentioned in the 3) and 4). It may be concluded that it is not necessary to take the inserting direction in consideration when the increment borer is used for the measurement of the diameter growth. 
Type Local  :  紀要論文 
ISSN  :  04857828 
Publisher  :  琉球大学農家政工学部 
URI  :  http://hdl.handle.net/20.500.12000/23248 
Citation  :  琉球大学農家政工学部学術報告 = The science bulletin of the Division of Agriculture, Home Economics & Engineering, University of the Ryukyus no.12 p.139 192 
Appears in Collections  :  No.12 (1965/10)

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