Abstract
Natural resource management requires knowledge of terrestrial evapotranspiration (ET). Most existing numeric models for ET include multiple plant- or ecosystem-type specific parameters that require calibration. This is a significant source of uncertainty under changing environmental conditions. A novel ET model with no type−specific parameters was developed recently. Based on the coupling the diffusion (via stomata) of water and carbon dioxide (CO2), this model predicts canopy conductance based on environmental conditions using eco-evolutionary optimality principles that apply to all plant types. Transpiration (T) and ET are calculated from canopy conductance using the Penman-Monteith equation for T and a universal empirical function for the T:ET ratio. Here, the model is systematically evaluated at globally distributed eddy-covariance sites and river basins. Site-scale modelled ET agrees well with flux data (r = 0.81, root mean square error = 0.73 mm day–1 in 23,623 records) and modelled ET in 39 river basins agrees well with the ET estimated by monthly water budget using two runoff datasets (r = 0.62 and 0.66, respectively). Modelled global patterns of ET are consistent with existing global ET products. The model's universality, parsimony and accuracy combine to indicate a broad potential field of application in resource management and global change science.
Original language | English |
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Article number | 109478 |
Journal | Agricultural and Forest Meteorology |
Volume | 336 |
Early online date | 2 May 2023 |
DOIs | |
Publication status | Published - 1 Jun 2023 |
Bibliographical note
Funding Information:This research was supported by the National Natural Science Foundation of China (no. 31971495 , 42001356 , 32022052 ). ICP and RLBN acknowledges support from the European Research Council under the European Union's Horizon 2020 research and innovation programme (grant agreement No: 787203 REALM) and the High-End Foreign Expert program of the China State Administration of Foreign Expert Affairs at Tsinghua University (No: G202210301 ). This work is a contribution to the LEMONTREE (Land Ecosystem Models based On New Theory, obseRvations and ExperimEnts) project, funded through the generosity of Eric and Wendy Schmidt by recommendation of the Schmidt Futures programme. We thank the FLUXNET community for providing tower-based flux observation. We also like to thank the Google Earth Engine team for providing calculation resource and distribution platform.
Funding Information:
This research was supported by the National Natural Science Foundation of China (no. 31971495, 42001356, 32022052). ICP and RLBN acknowledges support from the European Research Council under the European Union's Horizon 2020 research and innovation programme (grant agreement No: 787203 REALM) and the High-End Foreign Expert program of the China State Administration of Foreign Expert Affairs at Tsinghua University (No: G202210301). This work is a contribution to the LEMONTREE (Land Ecosystem Models based On New Theory, obseRvations and ExperimEnts) project, funded through the generosity of Eric and Wendy Schmidt by recommendation of the Schmidt Futures programme. We thank the FLUXNET community for providing tower-based flux observation. We also like to thank the Google Earth Engine team for providing calculation resource and distribution platform.
Publisher Copyright:
© 2023
Keywords
- Canopy conductance
- Eco-evolutionary optimality
- Evapotranspiration
- Remote sensing
- Transpiration
- Water balance