アマゾンの川から排出される二酸化炭素の源として若い有機物質
Emilio Mayorga1, Anthony K Aufdenkampe, Caroline A Masiello
1School of Oceanography, University of Washington, Seattle, Washington 98195, USA. emiliomayorga@alum.mit.edu
Nature
|July 29, 2005
まとめ
アマゾン川は,新鮮な有機物の呼吸により,かなりの量の二酸化炭素を放出します. 小さく,急速に循環する炭素プールが,これらの大きな流れを陸から大気へと駆動している.
科学分野:
- 環境科学 環境科学
- バイオジオケミストリー バイオジオケミストリー
- イソトープ地球化学 イソトープ地球化学
背景:
- 川は二酸化炭素で過飽和し,かなりのガス逃逸につながります.
- アマゾン川は二酸化炭素を大量に排出しており,地域の炭素予算に悪影響を及ぼしています.
- 河川における呼吸炭素の発生源と流通時間については,依然として議論の余地がある.
研究 の 目的:
- アマゾン川の二酸化炭素過飽和を誘発する炭素の源と循環を調査する.
- 河川システム内で呼吸する有機物質の年齢と起源を決定する.
- 炭素同位体組成を二酸化炭素回避フローと結びつけるために.
主な方法:
- 炭素同位体組成 (13Cと14C) の広範な調査.
- 溶解した無機炭素と3つの有機炭素のサイズ分子の分析.
- アマゾンの河川システム全体でサンプリング.
主要な成果:
- 現代の有機物質 (5歳未満) の呼吸は,過剰なCO2の主要な源です.
- 河川で運ばれる大量の有機炭素分子は,かなり古い (数十年から数千年).
- 小さく,急速に循環する有機炭素プールが,高い逃避フローを燃料にしています.
結論:
- 現代の陸上および川の近くの有機物質は,アマゾン川のCO2排出を燃料にしています.
- 小さな有機炭素プールの急速な循環は,大きな熱帯河川の炭素流れを理解するための鍵です.
- この発見は,地域的な炭素予算や気候モデルに影響を及ぼします.
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