河頭流の河頭流から流域からの窒素輸出の制御
B J Peterson1, W M Wollheim, P J Mulholland
1Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA.
まとめ
ヘッドウォーターの流れは,より大きな水体に栄養素の輸出を大幅に制御します. 最小の流れは窒素を素早く変換し,水の質と大気中の酸化窒素に影響を与えます.
科学分野:
- 環境科学 環境科学
- エコロジー エコロジー エコロジー
- 水文学 水文学とは,水文学の学問である.
背景:
- ヘッドウォーターの流れは,流域の栄養循環の重要な構成要素です.
- これらのシステムの窒素動態を理解することは,下流の水の質を管理するために不可欠です.
研究 の 目的:
- 北米の河頭川の窒素動態を,多様なバイオームにわたって調査する.
- 栄養素の加工と輸出における流れの役割を定量化する.
主な方法:
- 比較 (15) N-トレーサー研究設計を用いた.
- さまざまなストリームサイズで窒素の吸収と変換率を分析した.
主要な成果:
- 最小の流れでは,アンモニアと窒素酸塩の除去が最速であった.
- アンモニアは数十メートルから数百メートル以内に除去され,窒素は5〜10倍の距離を移動しました.
- 高い窒化率が観察され,小流が酸化窒素の源であることを示唆した.
結論:
- ヘッドウォーターの流れ,特に小さな流れは,川,湖,河口への栄養素の負荷を調節する上で重要な役割を果たします.
- これらの流れは,生物学的活動期間の溶解した無機窒素の輸出を大幅に減少させます.
- 河頭流の処理能力は,水生生態系の健康と大気ガス交換の両方に影響を及ぼします.
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