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The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus >
No.16 (1969/10) >

 
Title :スギみぞ腐病にかかった幼令林の被害解析について(林学科)
Title alternative :Analytical studies on canker damage in a young Japan ceder forest infected by Cercospora sequoiae. (Department of Forestry)
Authors :平田, 永二
大宜見, 朝栄
Authors alternative :Hirata, Eiji
Ogimi, Choei
Issue Date :1-Oct-1969
Abstract :本調査は, 8年生スギ林分のスギ溝腐病による被害状況を測樹学的な立場から把握するためにおこなったものである。調査の結果は, およそ次のとおりである。1)被害木の本数は全本数の約69%である。2)被害下部の地際からの高さは, 約80%までが0∿9cmの範囲にある。3)被害長は, 1mを越えるものは, わずか8%で, 平均は56cmである。4)被害溝の長さ, 深さ, および巾は, 各々平均15.6cm, 1.6cm, 3.7cmで, 1本当り平均3個の被害溝を有する。5)被害部の材積は, 全材積の約31%である。6)今後成林させても価値がないと思われる林木は26本で, 材積の被害率(被害部材積/被害木材[table]積×100)が80%以上の林木である。7)みぞ腐病の直径生長量におよぼす影響は胸高直径が増大するにつれて大となる。8)健全木と被害木の生長率は平均67%および47%となり, 健全木の方が生育は良好である。9)みぞ腐病の連年材積生長量におよぼす影響は, 胸高直径が増大するにしたがって増加し, 本林においては, 平均0.1508m^3の被害を受けているものと推定される。これは, 全生長量の19.5%に相当する。
This research was done in order to assess the amount of damage fromSugi-Mizogusaredisease, caused by Cercospora sequoiae Ellis et Everhart, among 438 young Japan cedar trees 8 years old, in Yona Demonstration Forest, Okinawa, from the viewpoint of forest measurement in 1967. The results of the research are as follows : 1) Among the total number of trees in the stand, 69% are damaged. The major symptom is the development of vertical grooves in the lower part of the tree trunk. 2) 80% of the damaged trees have the damaged part of the stem ranging from 0cm to 9cm in the height from the ground to the lowest point of damage. 3) Only 8% of the damaged trees have a damaged part of the stem exceeding one meter in length. The average length of the damaged part of the stem is 56cm. 4) The averages of the length, the depth and the width of the vertical grooves are 15.6cm, 1.6cm and 3.7cm respectively. A damaged tree has an average three such vertical grooves. 5) The volume of the damaged part of the stem is 31% of the total volume. 6) The trees which are of no value even if care in tending was to be carried out in the future were 26 in number, with the percentage of the volume of the damaged part to the volume of the damaged tree more than 80%. 7) Increase in diameter of the trunk is influenced bySugi-Mizogusaredisease, and the effect increases with increase of diameter at breast height. 8) The mean of the growth percentage is 67% for sound trees and 47% for damaged trees. 9) The current annual growth increment is influenced bySugi-Mizogusaredisease, and the effect increases with increase of diameter at breast height. In this stand, the current annual growth of the volume which is damaged bySugi-Mizogusaredisease is estimated to be 0.1508m^3. This value is equal to 19.5% of the total growth increment.
Type Local :紀要論文
ISSN :0370-4246
Publisher :琉球大学農学部
URI :http://hdl.handle.net/20.500.12000/4557
Citation :琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus no.16 p.288 -301
Appears in Collections:No.16 (1969/10)

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