1997 Fiscal Year Final Research Report Summary
Development of concentration-gradient FACE experimental facilitics.
| Project/Area Number |
07556108
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
生物環境
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| Research Institution | The University of Tokyo |
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Principal Investigator |
KURATA Kenji The University of Tokyo Graduate School of Agricultural and Life Sciences Professor, 大学院・農学生命科学研究科, 教授 (90161736)
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| Co-Investigator(Kenkyū-buntansha) |
IBARAKI Yasuomi The University of Tokyo Graduate School of Agricultural and Life Sciences Assist, 大学院・農学生命科学研究科, 助手 (50242160)
GOTO Eiji The University of Tokyo Graduate School of Agricultural and Life Sciences Assoc., 大学院・農学生命科学研究科, 助教授 (00186884)
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| Project Period (FY) |
1995 – 1997
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| Keywords | Global Problems / Carbon Dioxide / FACE / Ecosystems / Chamber Effects / Machine Effects |
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| Research Abstract |
Free Air CO2 Enrichment (FACE) experiments have been attracting much attention as a research method on vegetation reaction to the elevated CO2 concentration in the atmosphere. This study aims at developing a new FACE system. The CO2 concentration within the FACE ring would not be kept at a uniform level, as existing or planned FACE experiments, but a constant gradient of the concentration would be created, so that vegetation reactions to different CO2 concentrations would be investigated within one FACE ring. Main results are as follows :
l.A simulation study revealed that even if the wind blows from the opposite direction, a similar concentration gradient could be created by adjusting the CO2 release positions and strength.
2.Wind tunnel experiments showed that effects of blowers, pipes, and jets from the CO2 release facilities (machine effects) would be large in the existing configurations, much less if we use pure CO2 gas and irrigation tubes for CO2 release, and even much less with the use of many thin vertical tubes.
3.Using irrigation tubes and pure CO2 gas, a prototype concentration-gradient FACE system was developed. The shape of the ring was a long and narrow hexagon. CO2 release was feedforward-controlled based on the wind speed and direction. In most cases, a concentration gradient could be created, though not constant. Difficult cases to create a gradient were that of the low wind speed (less than 0.5m/s) and that in which the wind blew from the high concentration area to the low one.
As a conclusion, a prototype of a concentration-gradient FACE system was successfully developed. However, there remained much room for improvement of the control method.
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