评论"增加生长季节的生产力促使温带树木更早的秋季叶子衰老"
1Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA. rnorby@utk.edu.
Science (New York, N.Y.)
|March 6, 2021
概括
大气中的二氧化碳 (CO2) 不会持续加速秋季叶子衰老. 大多数自由空气二氧化碳丰富 (FACE) 研究显示,在较高的二氧化碳水平下,叶子老化没有变化或延迟.
科学领域:
- 植物生理学
- 生态学
- 环境科学
背景情况:
- 大气中的二氧化碳 (CO2) 水平上升是全球气候变化的一个重要方面.
- 之前的研究表明,树木在高二氧化碳下增强的光合作用可以加速秋季叶子的衰老.
研究的目的:
- 评估二氧化碳驱动的光合作用加速树叶衰老的假设.
- 综合关于叶子衰老和脱落的自由空气二氧化碳丰富 (FACE) 实验的发现.
主要方法:
- 对涉及叶树的多次自由空气二氧化碳丰富 (FACE) 实验的数据进行审查和分析.
- 在高二氧化碳条件下与环境条件下观察到的叶子衰老和脱落模式的比较.
主要成果:
- 在高二氧化碳下增强光合作用和加快叶子衰老之间的联系并未得到FACE实验数据的一致支持.
- 在大多数FACE实验中,二氧化碳水平升高并没有改变叶子衰老或脱落的时间.
- 许多FACE实验表明,当树木接触到高CO2时,叶子衰老或脱落会延迟.
结论:
- 增加二氧化碳导致秋季树叶衰老的假设并未得到FACE研究的经验证据的支持.
- 与一些预测相反,较高的二氧化碳度似乎对叶子衰老和脱落有中和甚至延迟的影响.
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