Responses of evapotranspiration to droughts across global forests: a systematic assessment
Responses of evapotranspiration to droughts across global forests: a systematic assessment
复制标题
全球森林蒸散对干旱的响应：系统评估
DOI：
10.1139/cjfr-2019-0436
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发表时间：
2021
影响因子：
2.2
通讯作者：
Jiabing Wu
中科院分区：
文献类型：
--
作者：
Haoyu Diao;Anzhi Wang;Hong Yang;Fenghui Yuan;Dexin Guan;Jiabing Wu
Forest evapotranspiration (ET) is one of the most important factors influencing the terrestrial hydrological cycle and is prone to being influenced by increasing drought events. This highlights the need to understand the interaction between global forest ET and drought. Consequently, we drew 710 sets of ecosystem-scale ET observations from 69 forest sites around the world and then systematically assessed the ET anomalies during droughts across the dominant forest and climate types. Overall, the response of forest ET to drought is non-monotonic. Under severe and extreme droughts with long durations, ET was reduced in most of forests in the world. We attributed the decreased forest ET to both restricted water supply and restricted water consumption by forests; however, lower magnitude and short-term droughts generally increased forest ET, and in some cases, ET even exceeded precipitation during droughts. We attributed this to the increased surface evaporation and the utilization of deep water by deep root systems. Specifically, we find that the positive anomaly of ET under droughts implied the drought paradox, which acts to accelerate the terrestrial hydrological cycle and further amplify the drought. This study as a global synthetic analysis of case studies on the site scale may have great potential for understanding the importance of the drought-modulated forest water cycle and the possibility of increasing drought stress with the effects of the drought paradox.
