EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

 A review of Water Use Efficiency across space and time 

Simone Fatichi1, Athanasios Paschalis2, Sara Bonetti3, Gabriele Manoli3, and Christoforos Pappas4
Simone Fatichi et al.
  • 1National University of Singapore, Department of Civil and Environmental Engineering, Singapore, Singapore, (
  • 2Department of Civil and Environmental Engineering, Imperial College London, London
  • 3School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
  • 4Department of Civil Engineering, University of Patras, Rio Patras, Greece

Water Use Efficiency (WUE) is the variable linking assimilation and storage of carbon in plants with the release of water through transpiration. In this study, we combine multiple datasets including global scale leaf-level gas exchange measurements, tree-ring isotopes, flux-tower observations, and remote sensing products with mechanistic terrestrial biosphere modeling to evaluate whether WUE depends on precipitation or aridity levels and how changes in vapor pressure deficit affect ecosystem scale WUE and intrinsic water use efficiency (IWUE). A constrained range of WUE values across ecosystems and climates are observed with few noticeable exceptions. Observations and model simulations converge towards a weak WUE dependency on precipitation or aridity conditions.

Numerical simulations with a mechanistic model reveal two distinct signatures of VPD on site level WUE and IWUE, with high VPD resulting in increased IWUE, but decreased WUE. Relations with soil moisture are instead more complex and non-monotonic. Multiple data sources in combination with mechanistic modeling offer new insights on WUE variability across spatial and temporal scales and provide reference WUE values for future comparisons.

How to cite: Fatichi, S., Paschalis, A., Bonetti, S., Manoli, G., and Pappas, C.:  A review of Water Use Efficiency across space and time , EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-12507,, 2023.