| Project/Area Number |
14560112
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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 | Chiba University |
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Principal Investigator |
SUZUKI Akira Chiba University, Faculty of Education, Professor, 教育学部, 教授 (50110797)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2003: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2002: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | litter decomposition / high nitrogen concentration stress / ammonia fungi / larch / lodge-pole pine / urea application / pH / ammonium nitrogen concentration / 尿素施与 / 植物質分解 / アンモニア苗 / 高pH / 土壌理化学条件 / かく乱 |
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| Research Abstract |
A large amount of urea was spread over on the forest floor of larch forest in Japan and that of lodge-pole pine forest in Canada. pH values of the urea plots suddenly increased from 5-7 to 9, and then gradually declined to those levels of control plots within 3 months. NH_4-N and NO_3-N showed similar changing patterns observed in pH but returned slower to the control levels than pH. Seven and six species of saprobic ammonia fungi occurred on the urea plots in the larch and the pine forest, respectively. In the urea treatment, the decomposition of larch leaves embedded in the larch forest floor was accelerated faintly whereas that, of larch wood disks embedded in the larch forest was inhibited. In the pine forest, no statistical significant difference was observed in the decomposition rates between the pine leaves and the pine wood disks in the urea plots and those in the control plots. Coprinus sp. isolated from the urea plot of the pine forest and Coprinus phlyctidosporus isolated in Japan grew vigorously in the NH_4OH added larch leaves that had been sterilized by γ-rays irradiation. These suggest that in both forests, the ammonia fungi compensated the decomposition processes instead of previously dominating fungi under high nitrogen stresses.
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