| Project/Area Number |
15380114
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
林学・森林工学
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| Research Institution | Forestry and Forest Products Research Institute |
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Principal Investigator |
SAKAI Masaharu Forestry and Forest Products Research Institute, Kyushu Research Center, Senior Researcher, 九州支所, 主任研究員 (00353699)
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| Co-Investigator(Kenkyū-buntansha) |
KOBAYASHI Masahiro Forestry and Forest Products Research Institute, Department of Forest Site Environment, Senior Researcher, 立地環境研究領域, 主任研究員 (50353686)
OKADA Naoki Kyoto University, Faculty of Agriculture, Associate Professor, 農学研究科, 助教授 (40335302)
MURANO Kentaro National Institute for Environmental studies, Atmospheric Environment Division, Leader, 大気圏環境領域, 総合研究官 (40109905)
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| Project Period (FY) |
2003 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥11,300,000 (Direct Cost: ¥11,300,000)
Fiscal Year 2006: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2005: ¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2004: ¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2003: ¥4,600,000 (Direct Cost: ¥4,600,000)
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| Keywords | KOSA / Dry deposition / Aerosol / S0_2 gas / Sulfur isotope ratio / Evergreen forest / Stemflow / Throughfall / 樹間流 / 林外雨 / コジイ / トレーサー試験 |
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| Research Abstract |
In this research, it aims to evaluate the influence of Yellow-sand (KOSA) on the forest, to identify sulfur sources of SO_4^<2-> of rainwater (precipitation, thoughfall, stemflow) by the sulfur isotopic method, and to estimate contribution rate of dry deposition on total deposition.
The outline of the result at all periods is as follows.
We investigated qualitative change of rainwater in an evergreen broadleaved forest in a southern part of Japan
1. KOSA flies from a continental desert to Japan at the early spring. Observation frequency of KOSA is an increasing tendency for the long term. In the spring of 2002 when the especially maximum KOSA in Beijing was observed, the color of aerosol filter presented yellowish. The Ca^<2+> concentration of the aerosol at KOSA event became 20-70nmol/m^3, and was higher than these values (20 nmol/m^3 or less) at normal event. The ion concentrations in precipitation, thoughfall and stemflow at KOSA event were higher than these at normal event. The influe
… More
nce on the forest by KOSA was admitted.
2. The sulfate concentration and sulfur isotopic ratio of the wet deposition at 20 precipitation events and the dry deposition at 9 precipitation events were determined. The SO_4^<2-> concentrations increased in the order of precipitation, throughfall and stemflow, whereas their sulfur isotopic ratio( δ^<34>S) decreased in the order of precipitation, throughfall and stemflow. These results suggest that δ^<34>S-depleted light sulfur is added to throughfall and stemflow. On the other hand, δ^<34>S values of aerosol and gas were +2.7〜+5.3‰ and-2.1〜2.0‰, respectively. The latter is light enough to reduce the δ^<34>S values of throughfall and stemflow. Therefore we concluded that 1) SO_2 in dry deposition is the main substance causing low pH of stemflow and throughfall, 2) a lot of SO_4^<2-> with light δ^<34>S value are loaded to precipitation flowing down as stemflow and throughfall.
3. About 60 percent of total deposition (wet deposition and dry deposition) was loaded to the forest by a dry deposition, using the mass balance model. Less
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