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温帯森林の光合成と昼間の呼吸の季節性
R Wehr1, J W Munger2, J B McManus3
1Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USA.
Nature
|July 1, 2016
まとめ
地球の生態系は二酸化炭素 (CO2) を吸収する. 新しい研究によると 昼間の生態系の呼吸は 夜間の呼吸よりも低くなっており 森林の炭素交換に関する以前の仮定と 気候モデルの改善に挑戦しています
科学分野:
- エコロジー
- 生地化学
- 気候科学
背景:
- 地球上の生態系は重要な炭素吸収場であり,人類による二酸化炭素 (CO2) の排出を相殺する.
- 生態系の光合成と呼吸の正確な測定は 気候変動の予測に不可欠です
- 現在の方法は,想定された環境反応に基づいて,生態系-大気CO2交換 (NEE) からこれらのフローを推論します.
研究 の 目的:
- 温帯の葉の森で 生態系の光合成と昼間の呼吸を直接測定する
- 森林における昼間の炭素流動パターンの 普遍的な見解に異議を唱えるため
- 地上生物圏モデルと遠隔感知指標の精度を向上させる.
主な方法:
- 生態系における炭素の流れを直接測定するために新しい同位体計測器を使用した.
- 温帯の葉の森で 3年間の研究を行いました
- 標準的なNEEベースの推定値と直接測定値を比較した.
主要な成果:
- 生態系呼吸が昼間より低くなることが示され,生態系スケールでの葉の呼吸の光阻害を示しています.
- 標準的な方法では 生態系の光合成と 日中の呼吸を過大評価しています
- 従来のアプローチによる生態系光合成光利用効率の描写における不正確さ
結論:
- 森林と大気間の炭素交換の理解を 修正しています
- 葉のレベルでの呼吸の軽い阻害は,生態系規模の炭素ダイナミクスに大きな影響を及ぼします.
- この発見は,地上の生物圏モデルを改良し,多様な生態系における炭素循環を理解するための基盤を提供します.
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