全球用水效率因蒸汽压力缺陷增加而和
Fei Li1,2, Jingfeng Xiao3, Jiquan Chen2
1Grassland Research Institute, Chinese Academy of Agricultural Sciences, Hohhot 010010, China.
概括
自2001年以来,全球生态系统的用水效率 (WUE) 没有提高. 气候变化带来的蒸汽压力缺口 (VPD) 增加抵消了大气中二氧化碳 (CO2) 增加对植物用水的好处.
科学领域:
- 地球系统科学
- 生态学
- 气候科学
背景情况:
- 生态系统用水效率 (WUEeco) 是碳同化与蒸发的比率.
- 大气中二氧化碳 (CO2) 的增加预计会增加WUE.
- 碳排放和气候变化对WUE的互动影响尚不清楚.
研究的目的:
- 调查WUEeco的全球趋势
- 确定大气中的CO2和气候变化对WUE的影响.
- 预测地球碳和水循环的未来变化.
主要方法:
- 使用机器学习方法进行升级估计.
- 分析自2001年以来的全球FLUXNET观测结果.
主要成果:
- 自2001年以来,全球WUE生态没有增加.
- 增加的蒸汽压力缺陷 (VPD) 抑制了光合作用并增强了ET.
- 温度升高和VPD是ET的关键调节因素,可能比口腔导电性更重要.
结论:
- 气候变化,特别是越来越多的VPD,对WUE2的预期好处产生了抵消作用.
- 未来的VPD增加可能会显著改变陆地碳和水循环之间的合.
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