Critical thresholds for nonlinear responses of ecosystem water use efficiency to drought.

Autor: Hu Y; State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China., Wei F; Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of sciences, Beijing 100101, China., Wang S; State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China., Zhang W; Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark., Fensholt R; Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark., Xiao X; Department of Microbiology and Plant Biology, Center for Earth Observation and Modeling, University of Oklahoma, Norman, OK, USA., Fu B; State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: bfu@rcees.ac.cn.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Mar 25; Vol. 918, pp. 170713. Date of Electronic Publication: 2024 Feb 05.
DOI: 10.1016/j.scitotenv.2024.170713
Abstrakt: Climate change is expected to lead to greater variability in precipitation and drought in different regions. However, the responses of ecosystem carbon and water cycles (i.e., water use efficiency, WUE) to different levels of drought stress are not fully understood. Here, we examined the relationship between WUE and precipitation anomalies and identified the critical drought threshold (Dr CW ) above which WUE showed substantial decrease. The results revealed that 85.56 % of the study area had nonlinear WUE responses to drought stress; that is, the WUE decreased sustainably and steeply when the precipitation deficit exceeded the Dr CW . Dr CW indicates inflection points for changing ecosystem responses from relatively resistant to vulnerable to drought stress, thus providing an instructive early warning for intensifying suppressive impacts on vegetation growth. Additionally, Dr CW varies across aridity gradients and among vegetation types. Based on the Dr CW at the pixel level, the future eco-drought is projected to increase in >67 % of the study area under both the SSP2&RCP4.5 and SSP5&RCP8.5 scenarios by the end of the 21st century. Our study elucidates the response of the ecosystem function to drought and supports the development of accurate ecosystem adaptation policies for future drought stress.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024. Published by Elsevier B.V.)
Databáze: MEDLINE
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