Pan et al. (2025) Impact of permafrost degradation on alpine grasslands in the Three-Rivers Headwater Region

Identification

• Journal: CATENA
• Year: 2025
• Date: 2025-11-20
• Authors: Yao Pan, Lei Liu
• DOI: 10.1016/j.catena.2025.109631

Research Groups

• Aerospace Information Research Institute, Henan Academy of Sciences
• The School of Geo-Science and Technology, Zhengzhou University

Short Summary

This study investigated the impact of permafrost degradation, measured by active layer thickness (ALT) and soil non-frozen period (NFP), on alpine grassland growth in the Three-Rivers Headwater Region (TRHR) from 2000 to 2020 using satellite data and statistical methods. It found significant permafrost degradation and grassland greening, with ALT and NFP having complex, spatially varying effects on grassland growth, suggesting potential future instability in warmer regions.

Objective

• To analyze permafrost degradation by measuring active layer thickness (ALT) and the soil non-frozen period (NFP) using satellite data.
• To investigate the impacts of permafrost degradation (ALT and NFP) on alpine grassland growth in the Three-Rivers Headwater Region (TRHR), while jointly accounting for climate variables.

Study Configuration

• Spatial Scale: Three-Rivers Headwater Region (TRHR) on the Tibetan Plateau.
• Temporal Scale: 2000 to 2020.

Methodology and Data

• Models used: Partial Least Squares (PLS) regression method.
• Data sources: Satellite data (for active layer thickness, soil non-frozen period, and grassland growth), climate variables (temperature, precipitation, sunshine duration).

Main Results

• Significant permafrost degradation occurred from 2000 to 2020 in the TRHR.
• Active layer thickness (ALT) thickened at a rate of 7.79 cm per decade (p < 0.05).
• The soil non-frozen period (NFP) lengthened by 1.1 days per year (p < 0.05).
• Alpine grassland vegetation exhibited a significant greening trend of 0.0014 per year (p < 0.01).
• ALT thickening was the dominant explanatory variable for grassland growth in 11.09 % of the region, showing a positive correlation in relatively cold western and alpine areas, but a negative correlation in relatively warm eastern and central regions.
• NFP extension was the dominant explanatory variable for grassland growth in 10.38 % of the region, although its positive correlation weakened as climate conditions transitioned from relatively cold-dry to relatively warm-wet.
• While permafrost degradation was positively correlated with grassland greening in relatively cold regions, the diminishing benefit of NFP extension and the adverse effects of ALT thickening may increasingly undermine grassland stability in relatively warm regions under further climate warming.

Contributions

• Quantifies the rates of permafrost degradation (ALT thickening and NFP lengthening) and grassland greening in the TRHR over two decades using satellite data.
• Provides a comprehensive analysis of the spatially varying impacts of permafrost degradation (ALT and NFP) on alpine grassland growth, distinguishing between cold and warm regions.
• Integrates permafrost degradation variables with climatic factors (temperature, precipitation, sunshine duration) to explain grassland dynamics, addressing limitations of previous studies focusing solely on climate.
• Highlights the complex and potentially adverse long-term effects of permafrost degradation on grassland stability, particularly in warmer regions, despite initial greening trends.

Funding

• Not specified in the provided text.

Citation

@article{Pan2025Impact,
  author = {Pan, Yao and Liu, Lei},
  title = {Impact of permafrost degradation on alpine grasslands in the Three-Rivers Headwater Region},
  journal = {CATENA},
  year = {2025},
  doi = {10.1016/j.catena.2025.109631},
  url = {https://doi.org/10.1016/j.catena.2025.109631}
}