Lu et al. (2026) Water availability controls growing season length divergence between karst and non-karst forests

Identification

• Journal: Agricultural and Forest Meteorology
• Year: 2026
• Date: 2026-09-15
• Authors: Jun Lu, Yuemin Yue, Hu Du, Wei Fu, Kelin Wang
• DOI: 10.1016/j.agrformet.2026.111480

Research Groups

• Institute of Subtropical Agriculture, Chinese Academy of Sciences (CAS)
• Huanjiang Agriculture Ecosystem Observation and Research Station of Guangxi
• Guangxi Key Laboratory of Karst Ecological Processes and Services
• National Earth System Science Data Center

Short Summary

This study investigates the length of the growing season (LOS) in subtropical karst forests and non-karst forests across southwestern China. The results show that LOS has advanced significantly in both forest types, but at a faster rate in karst forests.

Objective

• Investigate the interannual variation and long-term trends in LOS between karst and non-karst forests.
• Disentangle the sensitivity of LOS to thermal versus hydrological climatic drivers in the two forest types.

Study Configuration

• Spatial Scale: 500 m spatial resolution, covering southwestern China (Yunnan, Guizhou, and Guangxi provinces).
• Temporal Scale: 2001-2024 period, with daily data for temperature, precipitation, photosynthetically active radiation (PAR), and soil moisture.

Methodology and Data

• Models used: Piecewise logistic modeling approach to fit the satellite-derived GPP time series.
• Data sources:
  • MODIS Collection V061 gridded GPP product (MOD17A2)
  • In situ GPP data from six flux sites
  • Climate datasets: CHELSA, CHIRPS v3, MCD18A2, and National Earth System Science Data Center

Main Results

• The length of the growing season (LOS) has advanced significantly in both karst and non-karst forests.
• LOS extended at a faster rate in karst forests (2.207 days/year) than in non-karst forests (1.672 days/year).
• Partial least squares regression revealed that soil moisture and precipitation variables dominate the climatic controls on LOS in karst forests, while radiation and temperature variables control LOS in non-karst forests.

Contributions

• This study highlights the importance of considering water availability when predicting the phenological responses of karst ecosystems to climate change.
• The findings provide new insights into the contrasting climatic controls on LOS between karst and non-karst forests, which have implications for forest management and conservation.

Funding

• National Natural Science Foundation of China (Grant No. 42161148001)
• Guangxi Key Laboratory of Karst Ecological Processes and Services (Grant No. GXKLPES2020-02)

Citation

@article{Lu2026Water,
  author = {Lu, Jun and Yue, Yuemin and Du, Hu and Fu, Wei and Wang, Kelin},
  title = {Water availability controls growing season length divergence between karst and non-karst forests},
  journal = {Agricultural and Forest Meteorology},
  year = {2026},
  doi = {10.1016/j.agrformet.2026.111480},
  url = {https://doi.org/10.1016/j.agrformet.2026.111480}
}