コメント "成長期の生産性の向上は,温帯の木々の秋の葉の老化を早める"
1Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA. rnorby@utk.edu.
Science (New York, N.Y.)
|March 6, 2021
まとめ
大気中の二酸化炭素 (CO2) の上昇は,落ち葉の木の秋の葉の老化を一貫して加速しません. 大抵の空気のCO2濃縮 (FACE) 試験では,CO2濃度が高い状態では,葉の老化が変化しないか,遅れていることが示されている.
科学分野:
- 植物生理学
- エコロジー
- 環境科学
背景:
- 大気中の二酸化炭素 (CO2) 濃度の上昇は,地球規模の気候変動の重要な側面です.
- 以前の研究では 高濃度の二酸化炭素下での 樹木の光合成が 秋の葉の老化を早めると示唆されていました
研究 の 目的:
- 二酸化炭素による光合成の増加が 葉の老化を加速させるという仮説を評価する.
- 葉の老化と脱落に関するフリーエアCO2濃縮 (FACE) 実験の発見を合成する.
主な方法:
- 落ち葉の木を対象とした多重フリーエアCO2濃縮 (FACE) 実験のデータのレビューと分析.
- 葉の老化と脱落パターンの比較
主要な成果:
- 増加したCO2下での光合成と葉の老化の間の提案されたリンクは,FACE実験のデータによって一貫して支持されませんでした.
- ほとんどのFACE実験では,高濃度のCO2は葉の老化や脱落のタイミングを変化させなかった.
- FACEの実験の顕著な部分は,木が高濃度のCO2にさらされたときに葉の老化または脱落が遅れたことを示しました.
結論:
- CO2の上昇が秋の葉の老化を促すという仮説は,FACE研究からの経験的証拠によって支持されていません.
- CO2濃度の上昇は,いくつかの予測に反して,葉の老化と枯渇を中和または遅らせるように見える.
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