Response of Ecosystem Productivity to High Vapor Pressure Deficit and Low Soil Moisture: Lessons Learned From the Global Eddy-Covariance Observations

Shiqin Xu*, Pierre Gentine, Lingcheng Li*, Lixin Wang, Zhongbo Yu, Ningpeng Dong, Qin Ju, Yuliang Zhang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Although there is mounting concern about how high vapor pressure deficit (VPD) and low soil moisture (SM) affect ecosystem productivity, their relative importance is still under debate. Here, we comprehensively quantified the relative impacts of these two factors on ecosystem gross primary production (GPP) using observations from a global network of eddy-covariance towers and two approaches (sensitivity analysis and linear regression model). Both approaches agree that a higher percentage of sites experience GPP reduction from high VPD than from low SM over the growing season. However, the constraint of high VPD and low SM on GPP reduction is tightly linked with climates and plant functional types. Humid and mesic ecosystems including forests and grasslands are dominated by VPD, while the semi-arid and arid ecosystems including shrublands and savannas are dominated by SM. The varying dominant role of these two factors on GPP is closely related to plant stomatal behavior, as predicted by a stomatal conductance model. Additionally, we highlight the non-linear impact of SM on GPP during droughts and the possible underestimation of the SM effects for deep-rooted plants when only using surface-layer SM. Our results shed light on a better understanding of the impacts of VPD and SM on vegetation productivity, with important implications for modeling the response and feedback of ecosystem dynamics to current and future climates.

Original languageEnglish (US)
Article numbere2022EF003252
JournalEarth's Future
Volume11
Issue number8
DOIs
StatePublished - Aug 2023

Keywords

  • climate change
  • drought events
  • ecosystem production
  • plant hydraulics
  • stomatal conductance model
  • water stress

ASJC Scopus subject areas

  • General Environmental Science
  • Earth and Planetary Sciences (miscellaneous)

Fingerprint

Dive into the research topics of 'Response of Ecosystem Productivity to High Vapor Pressure Deficit and Low Soil Moisture: Lessons Learned From the Global Eddy-Covariance Observations'. Together they form a unique fingerprint.

Cite this