Ma et al. (2026) Divergent response of vegetation structure to land-atmosphere droughts across aridity gradients in the Northern Hemisphere

Identification

• Journal: Global and Planetary Change
• Year: 2026
• Date: 2026-02-26
• Authors: Bingxin Ma, Longhui Li, Yue Zhang, Yueyue Dou, Lin Yu
• DOI: 10.1016/j.gloplacha.2026.105391

Research Groups

• State Key Laboratory of Climate System Prediction and Risk Management, Nanjing Normal University, Nanjing, China
• Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing, China
• Cultivation Laboratory of Geographical Environmental Evolution and Regional Response for National-Class Key Laboratory, Nanjing, China
• College of Geographical Science and Tourism, Xinjiang Normal University, Urumqi, China

Short Summary

This study used machine learning to investigate the relative contributions of soil moisture (SM) and vapor pressure deficit (VPD) to leaf area index (LAI) across aridity gradients in the Northern Hemisphere, revealing a "seesaw effect" where SM's contribution decreases and VPD's increases with aridity.

Objective

• To investigate the relative contributions of soil moisture (SM) and vapor pressure deficit (VPD) to the leaf area index (LAI) from 1982 to 2020 in the Northern Hemisphere, considering aridity gradients and temporal effects.

Study Configuration

• Spatial Scale: Northern Hemisphere
• Temporal Scale: 1982 to 2020

Methodology and Data

• Models used: Eight machine learning algorithms
• Data sources: Soil moisture (SM), vapor pressure deficit (VPD), and leaf area index (LAI) datasets

Main Results

• The relative contribution of soil moisture (SM) to leaf area index (LAI) decreased with aridity index (AI), ranging from 0.63 ± 0.09 in arid regions to 0.24 ± 0.09 in humid regions.
• The relative contribution of vapor pressure deficit (VPD) to LAI increased with AI, ranging from 0.37 ± 0.09 in arid regions to 0.76 ± 0.09 in humid regions.
• When considering combined time lag (TL) and time accumulation (TA) effects, the relative contribution of SM to LAI was enhanced, while the relative contribution of VPD to LAI was significantly attenuated across the Northern Hemisphere, except in arid regions (AI < 0.2).
• The study identified a "seesaw effect" of land and atmosphere drought on vegetation structural changes.

Contributions

• Quantified the divergent relative contributions of land drought (SM) and atmosphere drought (VPD) to vegetation structure (LAI) across aridity gradients in the Northern Hemisphere.
• Demonstrated the significant influence of combined time lag and time accumulation effects on the relative contributions of SM and VPD.
• Provided insights into the "seesaw effect" of land and atmosphere drought, which can improve predictions of vegetation response to future climate changes.

Funding

• [No specific funding information provided in the excerpt.]

Citation

@article{Ma2026Divergent,
  author = {Ma, Bingxin and Li, Longhui and Zhang, Yue and Dou, Yueyue and Yu, Lin},
  title = {Divergent response of vegetation structure to land-atmosphere droughts across aridity gradients in the Northern Hemisphere},
  journal = {Global and Planetary Change},
  year = {2026},
  doi = {10.1016/j.gloplacha.2026.105391},
  url = {https://doi.org/10.1016/j.gloplacha.2026.105391}
}