An et al. (2026) Scenario-dependent responses of soil conservation service flow to climate change across karst development gradients in the Pearl River Basin

Identification

• Journal: Ecological Indicators
• Year: 2026
• Date: 2026-03-14
• Authors: Jie An, Rui Li, Zhenhong Yi, Benjin Yu, Qianying Mei, Chaoyang Xue, Shitian Tang
• DOI: 10.1016/j.ecolind.2026.114758

Research Groups

• School of Karst Science, Guizhou Normal University, Guiyang, Guizhou, PR China
• State Engineering Technology Institute for Karst Desertification Control, Guiyang, Guizhou, PR China

Short Summary

This study quantifies the scenario-dependent responses of soil conservation service flow (SCSF) to climate change across different karst development degrees (KDDs) in the Pearl River Basin using a coupled Global Climate Model (GCM)-Soil and Water Assessment Tool (SWAT) framework, revealing that SCSF dynamics are significantly influenced by both climate scenarios and karst geomorphology.

Objective

• To quantitatively characterize the spatiotemporal patterns and evolutionary trends of SCSF under different CMIP6 emission scenarios (SSP126, SSP245, SSP585) during historical and future periods.
• To elucidate the regulatory mechanisms of climate change and Karst Development Degree (KDD) on SCSF.

Study Configuration

• Spatial Scale: Pearl River Basin (PRB), covering approximately 4.4 × 10^5 square kilometers, with a karst area of about 1.6 × 10^5 square kilometers (35% of the total basin area). The basin was divided into 88 sub-basins and 2718 Hydrological Response Units (HRUs).
• Temporal Scale:
  • Historical period: 1995–2014 for SCSF analysis; 1992–2015 for meteorological and hydrological data.
  • Future periods: 2010–2100, with specific analysis for 2060 and 2100.

Methodology and Data

• Models used:
  • Coupled Global Climate Model (GCM) ensemble (CanESM5, IPSL-CM6A-LR, MIROC6) from Coupled Model Intercomparison Project Phase 6 (CMIP6).
  • Soil and Water Assessment Tool (SWAT) model.
  • Modified Universal Soil Loss Equation (MUSLE) for soil erosion simulation.
  • Delta bias correction method for GCM outputs.
• Data sources:
  • Topography: Raster data (90 meter resolution, 2010) from Geospatial Data Cloud.
  • Land use: Raster data (30 meter resolution, 2000, 2010, 2020) from RESDC.
  • Soil type: Raster data (1 kilometer × 1 kilometer resolution, static) from National Cryosphere Desert Data center.
  • Meteorological data: Daily-scale (1992–2015) from China Meteorological Data Service Centre.
  • Hydrological data: Daily-scale (1992–2015) from the Hydrological Yearbook of the People's Republic of China.
  • China's Karst Distribution Data: SHP format (1 kilometer × 1 kilometer resolution, static) from Chinese Academy of Sciences.
  • NEX-GDDP-CMIP6: netCDF4 format (0.25° × 0.25° resolution, 2010–2100) from NASA.

Main Results

• Scenario-dependent SCSF responses:
  • Under SSP126, basin-scale SCSF exhibits a continuous increasing trend, rising from 7.96 × 10^6 tonnes to 8.97 × 10^6 tonnes compared to the historical baseline.
  • Under SSP245, a gradual increase in SCSF is observed.
  • Under SSP585, SCSF shows a rise-then-decline pattern, decreasing from 1.01 × 10^7 tonnes to 9.56 × 10^6 tonnes.
• Karst Development Degree (KDD) regulatory effect:
  • Full Coverage (FC) and High Coverage (HC) sub-basins consistently maintain higher and more stable SCSF levels.
  • Low Coverage (LC) and Non-karst Coverage (NC) sub-basins are more prone to fluctuations and declines under SSP585.
  • The highest mean SCSF occurs in FC areas under SSP126 (49.3 tonnes per hectare), while the lowest mean value is observed in LC areas under SSP585 (9.87 tonnes per hectare).
  • SCSF generally increases with higher KDD, with FC and HC areas showing significantly higher SCSF than LC and NC areas (p < 0.05).
• Historical SCSF (1995-2014): Soil conservation service flow volume exhibited a fluctuating upward trend, with an annual mean SCSF of 7.32 × 10^7 tonnes in 2014. FC (26.11 tonnes per hectare) and HC (25.13 tonnes per hectare) had markedly higher mean SCSF than LC (8.34 tonnes per hectare) and NC (11.00 tonnes per hectare).
• SCS Supply and Demand:
  • Future SCS supply consistently increases under SSP126 and SSP245 scenarios but shows a late-stage decline under SSP585. High supply values are concentrated in the southwestern karst mountainous region.
  • Future SCS demand declines under SSP126 but shows sustained increases under SSP245 and SSP585 scenarios. Demand remains higher in the middle and upper reaches.
• Model Performance: The SWAT model showed satisfactory performance for daily discharge and sediment simulations, with R^2 and Nash–Sutcliffe efficiency (NSE) values exceeding 0.5 for all calibrated and validated hydrological stations.

Contributions

• Systematically elucidates the regulatory mechanisms of climate change on soil conservation service flow (SCSF).
• Fills a research gap by providing insights into the differential SCSF responses across various Karst Development Degrees (KDDs).
• Enhances the understanding of coupled soil–water processes and ecosystem service flows, particularly in complex karst basins.
• Provides scientific support for effective soil erosion control and adaptive basin management strategies in karst regions.

Funding

• National Natural Science Foundation of China (Project codes: 32572153; 32360421)
• Guizhou Province Department of Science and Technology (Project code: QianKeHeJiChu-ZK [2023] Key 029)

Citation

@article{An2026Scenariodependent,
  author = {An, Jie and Li, Rui and Yi, Zhenhong and Yu, Benjin and Mei, Qianying and Xue, Chaoyang and Tang, Shitian},
  title = {Scenario-dependent responses of soil conservation service flow to climate change across karst development gradients in the Pearl River Basin},
  journal = {Ecological Indicators},
  year = {2026},
  doi = {10.1016/j.ecolind.2026.114758},
  url = {https://doi.org/10.1016/j.ecolind.2026.114758}
}