大気中の窒素堆積による太平洋北西部の窒素濃度の増加
Tae-Wook Kim1, Kitack Lee, Raymond G Najjar
1School of Environmental Science and Engineering, Pohang University of Science and Technology, Pohang, 790-784, Korea.
まとめ
大気堆積による窒素汚染は,北西太平洋で (P) よりも窒素 (N) を増加させた. このシフトにより,海洋生態系は窒素限度からリン限度へと変化した.
科学分野:
- 海洋化学 海洋化学について
- 海洋学 海洋学とは
- 環境科学 環境科学
背景:
- 1980年以来,北西太平洋の限界海は, (P) よりも窒素 (N) の相対的な豊富性が増加していることを示しています.
- この地域は,工業化されたアジア大陸の下流にあり,人類による影響を示唆しています.
研究 の 目的:
- 北西太平洋の限界海における窒素の供給量の増加の要因を調査する.
- 変化する栄養分比が海洋生態系制限に与える影響を判断する.
主な方法:
- 海水における栄養素濃度 (窒素とリン) に関する過去のデータの分析.
- 大気中の窒素堆積量の推定値と観測されたN濃度との相関分析.
- 特定の地域における河川による窒素の投入の評価.
主要な成果:
- 1980年以来,Pに対してNの有意な増加が観察されています.
- 大気中の窒素堆積は,高時間相関 (r = 0.74 から 0.88) を示す,増加したNの利用可能性の主な要因として特定されています.
- 河川の窒素の供給は,いくつかの地域では重要な要因であり,シフトに寄与しています.
結論:
- 主に大気中の堆積と河川からの窒素の供給の増加は,北西太平洋の限界海における栄養素のステキオメトリを変化させた.
- 広大な地域は,窒素に限られた生態系から,リンに限られた生態系へと移行した.
- これらの変化は,海洋の生地化学サイクルと生態系の機能に重大な影響を及ぼします.
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