Hu et al. (2026) Improved simulation of gross primary production and evapotranspiration in a drought-prone temperate deciduous forest with the BEPS-EcoHydro

Identification

• Journal: Agricultural and Forest Meteorology
• Year: 2026
• Date: 2026-01-22
• Authors: Lu Hu, Mousong Wu, Weimin Ju, Xiuli Xing, Jing M. Chen, Huajie Zhu
• DOI: 10.1016/j.agrformet.2026.111031

Research Groups

• International Institute for Earth System Science, Nanjing University, Nanjing, China
• School of Geography and Ocean Science, Nanjing University, Nanjing, China
• Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing, China
• Department of Environmental Science and Engineering, Fudan University, Shanghai, China
• Department of Geography and Planning, University of Toronto, Toronto, ON, Canada

Short Summary

This study integrated a plant hydraulics module into the BEPS-EcoHydro model to mechanistically represent water flow in the soil-plant-atmosphere continuum, significantly improving simulations of gross primary production and evapotranspiration, especially during drought, in a temperate deciduous forest.

Objective

• To integrate a plant hydraulics module into the process-based Biosphere-atmosphere Exchange Process Simulator (BEPS-EcoHydro) to mechanistically represent water flow in the soil-plant-atmosphere continuum (SPAC) and evaluate its performance in simulating carbon and water fluxes, particularly during drought, in a temperate deciduous forest.

Study Configuration

• Spatial Scale: Ecosystem scale (drought-prone temperate deciduous forest in the central USA).
• Temporal Scale: Hourly scale, covering periods of drought intensification and recovery.

Methodology and Data

• Models used: BEPS-EcoHydro (Biosphere-atmosphere Exchange Process Simulator) with an integrated plant hydraulics module; original BEPS for comparison.
• Data sources: Observational data for predawn leaf water potential, soil moisture, evapotranspiration (ET), and gross primary production (GPP) for model evaluation.

Main Results

• BEPS-EcoHydro effectively captured variations in predawn leaf water potential at the ecosystem scale with a coefficient of determination (R²) of 0.54 (p < 0.01).
• The model outperformed the original BEPS in simulating soil moisture, showing a 34% improvement in R².
• Simulation performance for evapotranspiration (ET) and gross primary production (GPP) was improved with BEPS-EcoHydro, especially at the hourly scale.
• BEPS-EcoHydro better captured drought impacts and detected hysteretic responses of GPP and ET to leaf water potential during drought intensification and recovery periods compared to the original BEPS.

Contributions

• Developed and evaluated BEPS-EcoHydro, a process-based ecosystem model that mechanistically incorporates plant hydraulics and SPAC water flow, moving beyond empirical soil moisture stress factors.
• Demonstrated the necessity of considering plant hydraulics in ecosystem models for a better understanding of vegetation responses to climate extremes, particularly drought.
• Provided a tool capable of capturing hysteretic responses of carbon and water fluxes to leaf water potential during drought.

Funding

• Not specified in the provided text.

Citation

@article{Hu2026Improved,
  author = {Hu, Lu and Wu, Mousong and Ju, Weimin and Xing, Xiuli and Chen, Jing M. and Zhu, Huajie},
  title = {Improved simulation of gross primary production and evapotranspiration in a drought-prone temperate deciduous forest with the BEPS-EcoHydro},
  journal = {Agricultural and Forest Meteorology},
  year = {2026},
  doi = {10.1016/j.agrformet.2026.111031},
  url = {https://doi.org/10.1016/j.agrformet.2026.111031}
}