中部大西洋のトリコデスミウムによる窒素固定のリン酸化制限
S A Sañudo-Wilhelmy1, A B Kustka, C J Gobler
1Marine Sciences Research Center, State University of New York, Stony Brook, New York 11794-5000, USA. ssanudo@notes.cc.sunysb.edu
Nature
|May 3, 2001
まとめ
海洋の生産性にとって極めて重要な海洋窒素の固定は,鉄によってのみ制限されるものではありません. この研究は,リン含量と光のレベルが,トリコデスミウムサイアノバクテリアによる窒素固定に影響を与える重要な要因であることを明らかにしています.
科学分野:
- 海洋微生物生態学について
- バイオジオケミカルサイクルとは
- 海洋学 海洋学 海洋学
背景:
- 海洋窒素固定は植物プランクトンに不可欠な栄養素を供給し,世界の炭素循環に影響を与えます.
- シアノバクテリア・トリコデスミウム (Trichodesmium) は,熱帯水域における窒素固定の主な原動力である.
- 以前の仮定では,鉄の利用可能性が海洋の窒素固定を制限することを示唆していた.
研究 の 目的:
- 海洋窒素固定率を制御する要因を調査する.
- トライコデスミウムによる窒素固定の調節における鉄の役割と他の栄養素の役割を再評価する.
主な方法:
- 大西洋中部でのフィールド観測.
- 窒素固定率,溶けた鉄,トリコデスミウム鉄含量,リン含量の測定.
- 照射率の分析と窒素固定との相関.
主要な成果:
- 窒素固定率は,溶けた鉄とトリコデスミウム鉄含有量とは無関係でした.
- 窒素固定は,トリコデスミウムリン含有量と強く相関しています.
- より高い照射により,窒素の固定率が向上した.
- 窒素固定装置の構造鉄の計算要件は,以前に推定されたよりも低い.
結論:
- 海洋の窒素固定は,鉄の供給によってのみ規制されるものではありません.
- の利用可能性と光は,窒素の固定を制御する重要な要因です.
- 鉄は特定の地域での成長を制限する可能性がありますが,普遍的な制限要因ではありません.
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