Li et al. (2026) Sustained transpiration masks weakened canopy cooling and emerging carbon constraints during heatwaves in a riparian poplar plantation

Identification

• Journal: Agricultural and Forest Meteorology
• Year: 2026
• Date: 2026-08-02
• Authors: Kexin Li, Hang Xu, Haijiao Wang, Zhipeng Li, Wenxu Cao, Xiaoyun Wu, Chao Zhang, Shengnan Chen, Zeyu Yuan, Zhiqiang Zhang
• DOI: 10.1016/j.agrformet.2026.111390

Research Groups

• Jixian National Forest Ecosystem Observation and Research Station, CNERN, School of Soil and Water Conservation, Beijing Forestry University, China
• Key Laboratory of Soil and Water Conservation & Desertification Combating, State Forestry and Grassland Administration, Beijing Forestry University, China
• Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, China
• State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, China

Short Summary

This study investigates the responses of a riparian poplar plantation to heatwaves, focusing on transpiration, canopy cooling, and carbon uptake. The results show that sustained transpiration during heatwave conditions does not fully maintain canopy thermal buffering.

Objective

• Investigate how water use, thermal regulation, and carbon allocation are coordinated in riparian plantations during heatwave conditions

Study Configuration

• Spatial Scale: A riparian poplar plantation located in the North China Plain
• Temporal Scale: Nine natural heatwave events from 2014 to 2023 (excluding 2020)

Methodology and Data

• Models used: None mentioned
• Data sources: Multi-year in situ measurements of carbon and water fluxes, micrometeorology, canopy temperature, and non-structural carbohydrates

Main Results

• Canopy transpiration became more strongly governed by atmospheric evaporative demand during heatwave conditions
• Sustained transpiration did not fully maintain canopy thermal buffering; midday canopy cooling weakened, and canopy temperature approached air temperature
• Carbon uptake declined, with lower gross primary productivity and stronger midday suppression
• Organ-specific non-structural carbohydrate reorganization occurred, including increased soluble sugars in leaves and roots, increased stem starch, and greater total NSC in roots

Contributions

• This study highlights that apparent hydraulic buffering in riparian plantations may conceal underlying adjustments in carbon uptake and allocation
• The findings underscore the need to integrate water fluxes, canopy thermal regulation, and carbon dynamics when assessing forest responses to climate extremes

Funding

• No funding information provided

Citation

@article{Li2026Sustained,
  author = {Li, Kexin and Xu, Hang and Wang, Haijiao and Li, Zhipeng and Cao, Wenxu and Wu, Xiaoyun and Zhang, Chao and Chen, Shengnan and Yuan, Zeyu and Zhang, Zhiqiang},
  title = {Sustained transpiration masks weakened canopy cooling and emerging carbon constraints during heatwaves in a riparian poplar plantation},
  journal = {Agricultural and Forest Meteorology},
  year = {2026},
  doi = {10.1016/j.agrformet.2026.111390},
  url = {https://doi.org/10.1016/j.agrformet.2026.111390}
}