| Project/Area Number |
04640611
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
生態学
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| Research Institution | OSAKA CITY UNIVERSITY |
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Principal Investigator |
YODA Kyoji Osaka City Univ., Fac.of Science, Professor, 理学部, 教授 (80046937)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1993: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1992: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Methane budget / Wetland / Emission / Forest soils / Absorption / Seasonal variation / 温度依存性 / 地球温暖化 / 温室効果ガス / 季節変動 |
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| Research Abstract |
To estimate the methane budget of the area consisting of various land use types, we measured methane emission rates from a Phragmites wetland and methane absorption rates by a forest in the area.
Methane emission rates from the Phragmites wetland showed clear seasonal variations. The highest mean emission rate of 17.72 mgCH4/m2/hr was observed in July and the lowest rate of 0.35 mgCH4/m2/hr was recorded in December. Aithough these results showed the dependency of the methane emission rates on temperature, water levels or Eh of soils also controlled the rates. Moreover, our measurements implied that the plants had a positive effect on methane emission from the wetland.
Methane absorption rates by the forest soils also showed seasonal variations, the maximum rate was observed in October. The results of our incubating experiments showed the forest soils gotten in any seasons absorbed best between 25ﾟC and 30ﾟC.Methane absorption rates changed with depths of soils, surface soils up to 20cm in depth absorbed it well. And the soils after sterilizing by autoclave did not absorb methane. This indicates that the methane absorption by soils is caused by biological processes.
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