Premium
Global Analysis of Ecosystem Evapotranspiration Response to Precipitation Deficits
Author(s) -
He Bin,
Wang Haiyan,
Guo Lanlan,
Liu Junjie
Publication year - 2017
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2017jd027817
Subject(s) - evapotranspiration , ecosystem , arid , precipitation , environmental science , eddy covariance , atmospheric sciences , climatology , ecology , geography , meteorology , geology , biology
Changes in ecosystem evapotranspiration (ET) due to precipitation deficits (PD) can relieve or aggravate soil moisture shortages, thus impacting drought severity. Previous findings have conflicted with regard to response of ET to PD. The present study relies on a global land ET synthesis data set (ET syn ) and observations from eddy‐covariance towers (ET obs ) to thoroughly examine the sensitivity of ET to PD, which is represented by the standardized precipitation index. There was a contrast in the response to PD between arid and humid ecosystems. ET syn of arid ecosystems was typically reduced promptly in response to a reduction of precipitation, while ET syn in humid ecosystems experienced a two‐staged change: First, there was an enhancement, and then a reduction associated with persisting PD. Compared with ET syn , ET obs suggests the occurrence of a more significant ET transition in response to PD. In arid ecosystems, ET typically negatively correlated with low PD, but this was limited by a large PD. Findings from this study are crucial for understanding the role of ET in drought evolution.