Wang et al. (2026) Moisture limitation superseding thermal forcing: Elevational divergence in growth and physiological responses of Picea crassifolia to accelerated warming and drying on the Northeastern Tibetan Plateau

Identification

• Journal: Agricultural and Forest Meteorology
• Year: 2026
• Date: 2026-07-24
• Authors: Xinrui Wang, Liang Jiao, Yarong Qin, Lan Chen, Peng Zhang, Xuge Wang, Kuan Zhang, WeiYin Shi
• DOI: 10.1016/j.agrformet.2026.111377

Research Groups

College of Geography and Environmental Science, Northwest Normal University, Lanzhou, China
Key Laboratory of Resource Environment and Sustainable Development of Oasis, Gansu Province, Northwest Normal University, Lanzhou, China

Short Summary

This study investigates the impact of accelerated warming and drying on Picea crassifolia growth and physiological responses along an elevational gradient in the northeastern Tibetan Plateau. The results show that moisture limitation supersedes thermal forcing, leading to divergent elevational responses in tree growth and water-use efficiency.

Objective

• Investigate how elevational gradients regulate tree growth and physiological responses of Picea crassifolia under accelerated warming and drying conditions.

Study Configuration

• Spatial Scale: Elevational gradient (high, middle, low) on the northeastern Tibetan Plateau.
• Temporal Scale: 1960 to 2020.

Methodology and Data

• Models used: ERA5-Land climate data, site-specific soil-moisture data.
• Data sources: Basal area increment (BAI), carbon isotope-derived intrinsic water-use efficiency (iWUE) from tree cores, satellite and observation data.

Main Results

• BAI and iWUE showed divergent elevational responses after 1984, with increasing trends at high elevation and declining trends at middle and low elevations.
• Site-specific climate analyses revealed that temperature limitation shifted to stronger heat- and moisture-related constraints at middle and low elevations.
• Structural equation modeling indicated a positive iWUE–BAI coupling at high elevation but negative effects at middle and low elevations after 1984.

Contributions

• This study highlights the importance of incorporating elevation-dependent climatic constraints, soil-water availability, and physiological-growth decoupling in future assessments of semi-arid mountain forest carbon sinks.
• The findings suggest that increasing iWUE does not necessarily translate into radial growth benefits under intensified moisture limitation.

Funding

• This research was supported by the National Natural Science Foundation of China (Grant No. 42171018) and the Key Laboratory of Resource Environment and Sustainable Development of Oasis, Gansu Province.

Citation

@article{Wang2026Moisture,
  author = {Wang, Xinrui and Jiao, Liang and Qin, Yarong and Chen, Lan and Zhang, Peng and Wang, Xuge and Zhang, Kuan and Shi, WeiYin},
  title = {Moisture limitation superseding thermal forcing: Elevational divergence in growth and physiological responses of Picea crassifolia to accelerated warming and drying on the Northeastern Tibetan Plateau},
  journal = {Agricultural and Forest Meteorology},
  year = {2026},
  doi = {10.1016/j.agrformet.2026.111377},
  url = {https://doi.org/10.1016/j.agrformet.2026.111377}
}