| Project/Area Number |
16510020
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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 |
Environmental impact assessment/Environmental policy
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| Research Institution | Niigata University |
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Principal Investigator |
NAKATA Makoto Niigata University, Institute of Science and Technology, Associate Prof., 自然科学系, 助教授 (80217744)
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| Co-Investigator(Kenkyū-buntansha) |
佐瀬 裕之 財団法人日本環境衛生センター, 酸性雨研究センター・生態影響研究部, 主任研究員
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2006: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2005: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2004: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Cryptomeria japonica forest / throughfall / slope position / sea salt / epicuticular wax / leaf surface wettability / stream water / acid shock / スギ人工林 / 試験流域 / 土壌の酸中和能 / 褐色森林土 / 公共用水域水質調査データ / pHの経年変化 / 酸性岩 / H^+負荷量 / 酸性降下物 / スギ人工林流域 / 地形的位置 / 海塩由来成分 / 物質収支 / 窒素飽和 / 地形条件 / 北西季節風 |
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| Research Abstract |
1. The deposition amounts (DAs) of inorganic constituents in a Cryptomeria japonica forest were investigated by measuring throughfall (TF) and stemflow (SF) chemistry at different slope positions in Niigata Prefecture. The total DAs at the upper, mid-, and lower slopes were 2.35, 2.40, and 1.70 times higher than that from rainfall, respectively. Deposition of most inorganic constituents, particularly those originating from sea salts, was higher significantly at the upper slope than the lower slope, which may have been due to materials transported by wind. Mean wind velocity at the nearest weather station showed a more significant positive correlation with the DAs (except for K^+ and nitrogen compounds), particularly for those originating from sea salts, than precipitation amount in the study area, especially at higher slope positions.
2. The DAs of NH_4^+ and K^+ from TF+SF might have a large effect on canopy interactions. The contact angle (CA) of water droplets on the C japonica leaves decreased with leaf aging, suggesting that surface wettability increases with leaf age. The K^+ concentration in TF was negatively correlated with the CA of one-year-old leaves, while the NH_4^+ concentration was positively correlated with the CA. The net DAs of NH_4^+ and NO_3^-from TF were positively correlated with the CA. The increase in leaf surface wettability may accelerate leaching of K^+ or uptake of nitrogen compounds on the forest canopy.
3. Stream water chemistry was compared between neighboring C japonica evergreen coniferous (CFs) and deciduous broad-leaved forests (BFs). The stream water chemistry was characterized by extremely high concentrations of Cl-and Na^+, which were thought to be mostly derived from sea salts. Acid shock was evident from late February to mid-March when the weather improved following cold snowy days in this snowy temperate region. This tendency was clearer in BFs than in CFs due to the different snowmelt patterns between the two forest types.
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