| Project/Area Number |
08660181
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
林学
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| Research Institution | Gifu University |
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Principal Investigator |
HIGO Mutsuki Gifu University, Faculty of Regional Studies, Assistant professor, 地域科学部, 助教授 (80198994)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1997: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1996: ¥600,000 (Direct Cost: ¥600,000)
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| Keywords | Secondary stand / stand structure / species composition / density-dependence / size structure / age structure / stratification / 一方向的競争 / 密度依存的死亡 |
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| Research Abstract |
A permanent plot set up in the stand regenerated on sites disturbed by Typhoon 15 in the experiment forest of Hokkaido University in 1986 (1 ha) and a permanent plot setup in the stand regenerated on cutover sites in 1992 (0.25ha) were investigated in 1996 and 1997, respectively. For the wind-disturbed site no prominent change of the species composition was observed during 10 years, while BA increased from 25.6m^2 to 30.0m^2/ha and the tree density decreased from 4527/ha to 3464/ha. During the period 1439 trees died and 376 trees were recruited the stand. For the cutover site BA was constant and tree density decreased from 1404/ha to 1260/ha. These results indicated that the structural change of the wind-disturbed site and the cutover site had been attributable to the mortality and the growth of trees. It became clear that tree mortality was density dependent and the mortality of smaller trees was higher than the mortality of larger trees. It was concluded that the developmental stage
… More
of these stand were the stem exclusion stage, in which the self-thinning resulted from the interaction between trees caused changes of stand structure.
In 1996, for the cutover site age of trees were analyzed by means of the increment core. Seventy five percentage of trees had ages between 40 and 60 years old, and the frequency distribution of tree age had a mode at 55-60 years old. Trees established immediately after the cutting had reached at various sizes after 60 years. These results showed that trees established immediately after the cutting had dominated the stand and the stratification among species was brought about by differences of the growth rate. Furthermore, individual trees within the same species had grown at different growth rates according to the growth condition affected by remnant larger trees which had not been cut before 60 years. These results suggested that the developmental process of these secondary stands were accompanied by the increase in the size variability among trees. Less
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