Li et al. (2026) Global Spring–Autumn Phenology Coupling Inferred from Satellite Observations and Reanalysis-Based Climate Limitations

Identification

• Journal: Remote Sensing
• Year: 2026
• Date: 2026-03-27
• Authors: Xiaolu Li, Yu Wei, Tong Qiu, Alison Donnelly, Yetang Wang
• DOI: 10.3390/rs18071002

Research Groups

• College of Geography and Environment, Shandong Normal University, Jinan, China
• Nicholas School of the Environment, Duke University, Durham, NC, USA
• Department of Geography, University of Wisconsin-Milwaukee, Milwaukee, WI, USA

Short Summary

This study globally assesses the coupling between spring and autumn phenology and its modulation by growing season climate limitations using satellite observations and reanalysis data. It reveals that spring onset primarily influences autumn senescence through a direct phenological pathway, with climate-mediated effects being smaller and spatially heterogeneous.

Objective

• To examine how growing season controlling factors (energy versus water limitation) are related to remote sensing-based spring–autumn phenological relationships.
• To assess the extent to which the timing of spring onset influences growing season climate-limitation regimes.
• To investigate how these relationships vary across land cover types and hydroclimatic contexts.

Study Configuration

• Spatial Scale: Global, at 0.1° (~11 km) resolution.
• Temporal Scale: 2001–2024 (24 years) for annual phenology and monthly climate data.

Methodology and Data

• Models used: Piecewise Structural Equation Modeling (SEM), Kendall's rank correlations.
• Data sources:
  • Satellite: Moderate Resolution Imaging Spectroradiometer (MODIS) Global Vegetation Phenology product MCD12Q2 Version 6.1 (for Start-of-Season (SOS) and End-of-Season (EOS) timings, derived from EVI2). MODIS Land Cover Type product MCD12C1 Version 6.1 (for land cover).
  • Reanalysis: ERA5-Land reanalysis (for latent heat flux (LH), shortwave solar radiation downward (SSRD), total volumetric soil water (SW)).

Main Results

• Globally, SOS and EOS are positively coupled, with later SOS generally followed by later EOS, and this relationship strengthens in late-SOS years.
• SOS does not induce coherent global shifts in growing season climate limitation regimes.
• Piecewise SEM indicates that SOS influences EOS primarily through a direct phenological pathway, with a mean path coefficient of approximately 0.4 day·day⁻¹ explaining about 26% of global EOS variability.
• Energy and water-mediated pathways contribute smaller (mean ~5% of explained variance) but spatially variable effects.
• SOS–EOS coupling is strongest in water-limited regimes, particularly in grasslands and shrublands.
• Managed croplands exhibit distinct and more heterogeneous responses, suggesting partial decoupling of phenology from natural hydroclimatic constraints.
• Wetter growing seasons consistently delay EOS (median ΔEOS = 1.2 days) and lengthen the growing season (median ΔLOS = 2.5 days), especially in arid and semi-arid regions, without systematic shifts in SOS.

Contributions

• Provides a global, observation-based assessment of the interactions between spring phenology and growing season climate controls in shaping autumn senescence.
• Offers new insights into the dominance of direct phenological coupling over climate-mediated effects in SOS–EOS relationships, with regional modulation by hydroclimatic conditions.
• Identifies specific hydroclimatic "hot spots" where climate-mediated influences are concentrated.
• Delivers process-based constraints to improve the representation of seasonal phenology coupling in land surface and Earth system models.

Funding

• National Key Research and Development Program of China (2020YFA0608202)
• National Natural Science Foundation of China (41971081)
• Shandong Provincial Natural Science Foundation (2026HWYQ-063)
• Shandong Postdoctoral Science Foundation (SDZZ-ZR-202501458)

Citation

@article{Li2026Global,
  author = {Li, Xiaolu and Wei, Yu and Qiu, Tong and Donnelly, Alison and Wang, Yetang},
  title = {Global Spring–Autumn Phenology Coupling Inferred from Satellite Observations and Reanalysis-Based Climate Limitations},
  journal = {Remote Sensing},
  year = {2026},
  doi = {10.3390/rs18071002},
  url = {https://doi.org/10.3390/rs18071002}
}