Luan et al. (2026) Stomatal conductance dominates land surface hydrological responses to rising CO2 concentrations in the Yellow River Basin

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-09-21
• Authors: Jinkai Luan, Ning Ma, Jun Ge, Fengxue Gu, Yue Wang, Wei Li, Qingyu Jia, Yuanyuan Yang, Hua Li, Zhihui Wang, Zhiguo Yu
• DOI: 10.1016/j.jhydrol.2026.136469

Research Groups

• Key Laboratory of Hydrometeorological Disaster Mechanism and Warning of Ministry of Water Resources/School of Hydrology and Water Resources, Nanjing University of Information Science and Technology
• Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences
• School of Atmospheric Sciences/Joint International Research Laboratory of Atmospheric and Earth System Sciences, Nanjing University
• Key Laboratory of Dryland Agriculture, Ministry of Agriculture and Rural Affairs, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences
• Institute of Water Resources for Pastoral Area, Ministry of Water Resources
• State Key Laboratory of Water Engineering Ecology and Environment in Arid Area, Xi’an University of Technology

Short Summary

This study investigates the impact of rising CO2 concentrations on land surface hydrology in the Yellow River Basin using a process-based ecohydrological model. The results show that stomatal conductance reductions dominate the effects of CO2-driven vegetation physiological and structural changes on evapotranspiration and runoff.

Objective

• Investigate how rising atmospheric CO2 concentrations modulate evapotranspiration (ET) and runoff (Q) across the Yellow River Basin through stomatal conductance and vegetation structure changes

Study Configuration

• Spatial Scale: The study focuses on the Yellow River Basin in northern China.
• Temporal Scale: The analysis is based on a 100 ppm increase in atmospheric CO2 concentrations.

Methodology and Data

• Models used: A process-based ecohydrological model was employed to quantify the effects of stomatal conductance and vegetation structure changes on ET and Q.
• Data sources: Satellite, observation, and reanalysis data were used to support the analysis.

Main Results

• Stomatal conductance reductions suppress ET but enlarge runoff, with a substantially greater impact than structural modifications.
• The interaction between stomatal conductance and vegetation structure increases ET and decreases runoff.
• Basin-wide sensitivity analysis indicates that a 100 ppm increase in atmospheric CO2 reduces ET by ~6.7 mm, primarily due to a ~7.6 mm reduction in ΔETstomata.

Contributions

• This study clarifies the pathways by which rising CO2 reshapes hydrological processes in a typical dryland basin.
• The results provide valuable insights for reducing uncertainty in water resource projections across semi-arid and arid regions.

Funding

• This research was funded by the Key Laboratory of Hydrometeorological Disaster Mechanism and Warning of Ministry of Water Resources.

Citation

@article{Luan2026Stomatal,
  author = {Luan, Jinkai and Ma, Ning and Ge, Jun and Gu, Fengxue and Wang, Yue and Li, Wei and Jia, Qingyu and Yang, Yuanyuan and Li, Hua and Wang, Zhihui and Yu, Zhiguo},
  title = {Stomatal conductance dominates land surface hydrological responses to rising CO2 concentrations in the Yellow River Basin},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.136469},
  url = {https://doi.org/10.1016/j.jhydrol.2026.136469}
}