海洋生物ポンプにおける炭素流減弱の解読ドライバー
M Bressac1,2, E C Laurenceau-Cornec3,4, F Kennedy3
1Sorbonne Université, CNRS, Laboratoire d'Océanographie de Villefranche, Villefranche-sur-Mer, France. matthieu.bressac@imev-mer.fr.
Nature
|September 11, 2024
まとめ
微生物の分解は,海洋の有機粒子 (POC) 流量減衰の7~29%を占め,動物プランクトンがより大きな役割を果たすことを示唆しています. 微生物の再鉱化率は海域や深さによって大きく変化した.
科学分野:
- 海洋学
- 海洋生物学
- 生地化学
背景:
- 生物学的ポンプは深海の炭素を吸収し 生態系に燃料を供給します
- メソペラジックにおける粒子有機炭素 (POC) 流の減衰は十分に理解されていません.
- 現在のモデルは,流量減衰の経験的"マーティン曲線"に依存しています.
研究 の 目的:
- メソペラジックにおける微生物媒介によるPOC流減弱を調査する.
- マーティン・カーブの背後にあるメカニズムの解明です
- 微生物の役割を様々な海洋システムで比較する
主な方法:
- C-RESPIRE装置を用いた現地実験
- 6つの海洋システムで複数のメソペラジック深さで展開する.
- 微生物媒介によるPOC流減弱の測定
主要な成果:
- 微生物の分解は,POC流の減衰に7~29%の割合で貢献した.
- 微生物の再鉱化がPOC流に正常化すると,各部位で20倍も変化した.
- 低緯度で垂直の傾向に影響を与え,他の場所では粒子の性質が優勢であった.
結論:
- 動物プランクトンは,これまで考えられていたよりもPOCフルス減弱に重要な役割を果たしている.
- 微生物の再鉱化は非常に変動し,複数の要因の影響を受けます.
- これらのメカニズムの理解は 海洋の炭素吸収モデルを 改良するために不可欠です
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