大気中のアンモニアの源またはシンクとしての自然植生:ケーススタディ
Science (New York, N.Y.)
|January 31, 1992
まとめ
コロラド州の森林は,大気レベルに基づいてアンモニアの吸収源または源として機能します. この窒素に限られた生態系は,他の地域よりも人為的な窒素を少なく受け取り,アンモニアの堆積から潜在的に恩恵を受けています.
科学分野:
- 環境科学 環境科学
- 大気化学 大気化学
- 森林生態学 森林生態学 森林生態学
背景:
- ガス状アンモニア (NH3) は,窒素堆積と生態系プロセスにおいて重要な役割を果たします.
- 山岳林は,大気中の窒素の投入に敏感であり,栄養バランスに影響を与えます.
- 森林と大気間のNH3交換を理解することは,生態系管理に不可欠です.
研究 の 目的:
- コロラド州のマウンテン・サブアルプス林が,ガス状アンモニアの源またはシンクとしての役割を調査する.
- 異なる大気濃度下での森林アンモニア補償点を決定する.
- この場所における人為的な窒素負荷を,世界の他の森林生態系における負荷と比較する.
主な方法:
- コロラド州のマウンテン・サブアルプス林の上部におけるガス状アンモニア濃度のフィールド測定.
- 周囲の大気中の濃度との関係におけるアンモニア流動の動態の分析.
- 森林平均のアンモニア補償ポイントの計算.
主要な成果:
- アンモニアの源や吸収源としての森林の役割は,周囲の大気中の濃度に依存していた.
- カノピーは,低濃度にさらされるとアンモニアの源として作用するが,農業で濃縮された空気にさらされるとシンクとして作用する.
- 森林平均の補償ポイントは,20°Cで10億分の0.8の量で決定されました.
結論:
- コロラド州の山岳亜アルプスの森林は,動的なアンモニア交換行動を示しています.
- この場所での人為的な窒素の負担が低いことは,この生態系にとって貴重な窒素資源である可能性があることを示唆しています.
- この発見は,森林と大気間のガス交換の決定において,大気中の濃度の重要性を強調している.
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