Li et al. (2026) Divergent Subtropical Forest Functional and Structural Responses to the 2022 Yangtze River Extreme Drought

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Journal of Geophysical Research Biogeosciences
• Year: 2026
• Date: 2026-04-01
• Authors: Baoni Li, Jiayi Liu, Dashan Wang, Xia Liu, Shijing Liang, Shuyu Zhang, Guoqing Gong, Ling Zeng, Zhilin Guo, Jianhuai Ye, Changhu Wang, Zhenzhong Zeng
• DOI: 10.1029/2025jg009291

Research Groups

Not specified in the abstract.

Short Summary

This study investigated the functional (greenness, photosynthesis) and structural (leaf area) responses of humid ecosystems in the Yangtze River Basin to the record-breaking 2022 drought. It revealed a striking decoupling where functional indicators declined while the structural indicator, leaf area index, unexpectedly increased, particularly in subtropical forests at higher elevations.

Objective

• To investigate how ecosystem functions (greenness and photosynthesis) and structures (leaf area) respond to unexpected extreme droughts in humid ecosystems, and whether these responses decouple.

Study Configuration

• Spatial Scale: Humid Yangtze River Basin
• Temporal Scale: 2022 growing-season drought; historical comparison period 2001–2022

Methodology and Data

• Models used: Machine learning models, SHapley Additive exPlanations (SHAP) analysis
• Data sources: Remote sensing (Normalized Difference Vegetation Index (NDVI), Solar-Induced Fluorescence (SIF), Leaf Area Index (LAI))

Main Results

• A striking divergence between ecosystem functional and structural responses was observed.
• NDVI decreased by 8.4% relative to the historical average (2001–2022).
• SIF declined by 2.2% relative to the historical average (2001–2022).
• LAI increased by 1.8% relative to the historical average (2001–2022).
• Subtropical forest LAI surged by 9.8%, despite a marked decline in NDVI and SIF.
• Leaf growth was enhanced, particularly at higher elevations with dense canopies and abundant antecedent soil moisture.
• Energy conditions, including air temperature, vapor pressure deficit, and solar radiation, were found to strongly regulate ecosystem responses to drought.

Contributions

• Demonstrates a novel function-structure decoupling in humid ecosystems under extreme drought conditions.
• Provides evidence that humid ecosystems can sustain structural growth despite functional impairment during drought, likely through complex physiological regulation and complementary resource utilization.
• Underscores the critical importance of incorporating this function-structure decoupling into photosynthesis and terrestrial carbon cycle estimations.

Funding

Not specified in the abstract.

Citation

@article{Li2026Divergent,
  author = {Li, Baoni and Liu, Jiayi and Wang, Dashan and Liu, Xia and Liang, Shijing and Zhang, Shuyu and Gong, Guoqing and Zeng, Ling and Guo, Zhilin and Ye, Jianhuai and Wang, Changhu and Zeng, Zhenzhong},
  title = {Divergent Subtropical Forest Functional and Structural Responses to the 2022 Yangtze River Extreme Drought},
  journal = {Journal of Geophysical Research Biogeosciences},
  year = {2026},
  doi = {10.1029/2025jg009291},
  url = {https://doi.org/10.1029/2025jg009291}
}