| Co-Investigator(Kenkyū-buntansha) |
MACHIMURA Takashi Osaka Univ., Grad.School of Eng, Associate.Prof, 大学院工学研究科, 助教授 (30190383)
HIRANO Takashi Hokkaido Univ., Research faculty of Agriculture, Prof., 大学院農学研究院, 教授 (20208838)
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| Budget Amount *help |
¥57,200,000 (Direct Cost: ¥44,000,000、Indirect Cost: ¥13,200,000)
Fiscal Year 2006: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2005: ¥11,440,000 (Direct Cost: ¥8,800,000、Indirect Cost: ¥2,640,000)
Fiscal Year 2004: ¥11,440,000 (Direct Cost: ¥8,800,000、Indirect Cost: ¥2,640,000)
Fiscal Year 2003: ¥11,960,000 (Direct Cost: ¥9,200,000、Indirect Cost: ¥2,760,000)
Fiscal Year 2002: ¥17,940,000 (Direct Cost: ¥13,800,000、Indirect Cost: ¥4,140,000)
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| Research Abstract |
In the Mid of Siberian Taiga, long term field measurements at disturbed and control sites on Carbon budget, heat and mass transfers were conducted. As to investigation, two observation towers were installed. Before disturbance intact Taiga forest absorbed carbon dioxide by 86mg/m^2.day, but after disturbance carbon dioxide was emitted from the ground by 140 mg/m2.day due to the loss of vegetation and increase of soil respiration. Loss of surface vegetation resulted in the increase of flux heat to the ground by 20% and it caused the large scale thawing of upper permafrost. The long term filed measurements of soil respiration by the method of open top camber indicated that the degree of soil respiration is proportional to soil temperature as well as soil moisture. The new empirical equations of these two factors were obtained. The highly concentrated methane as much as 2000 ppm was stored in the permafrost. After disturbance an additional thawing of upper permafrost resulted in the emission of stored methane to the atmosphere. Impact of permafrost disturbance under the global warming may the source of carbon dioxide and methane in Siberian permafrost area. There are three sources of green house gases induced by fire disturbance. 1) direct emission of carbon dioxide during combustion 2) at the burned site soil respiration was forced to increase by the increased soil temperature 3) in the process of permafrost thawing, stored methane was emitted to atmosphere. It may cause to the positive feedback of future global warming.
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