Zhang et al. (2025) Synergistic Regulation of Vegetation Greening and Climate Change on the Changes in Evapotranspiration and Its Components in the Karst Area of China

Identification

• Journal: Agronomy
• Year: 2025
• Date: 2025-10-11
• Authors: Geyu Zhang, Qiaotian Shen, Zijun Wang, Hao Li, Zongsen Wang, Tingyi Xue, Dangjun Wang, Haijing Shi, Yangyang Liu, Zhongming Wen
• DOI: 10.3390/agronomy15102375

Research Groups

• Key Laboratory of the Evaluation and Monitoring of Southwest Land Resources (Ministry of Education), Sichuan Normal University, Chengdu, China
• College of Grassland Agriculture, Northwest A&F University, Yangling, China
• College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, China
• Institute of Soil and Water Conservation, Northwest A&F University, Yangling, China

Short Summary

This study quantified the synergistic and competing effects of vegetation greening and climate change on evapotranspiration (ET) and its components in Southwest China's karst region (2000-2018) using a dual-scenario PT-JPL model. It found that vegetation restoration had a net positive effect on total ET, primarily driven by radiation and temperature, while precipitation had minimal direct influence.

Objective

• To quantify the synergistic and competing effects of vegetation greening and climate change on the spatiotemporal patterns of evapotranspiration (ET) and its components (canopy transpiration, interception evaporation, soil evaporation) in Southwest China's karst region.
• To elucidate the underlying driving mechanisms of vegetation and climatic factors on these ET variations.

Study Configuration

• Spatial Scale: Karst region of Southwest China (24°37′–29°13′ N, 103°36′–109°35′ E), encompassing parts of Guizhou, Yunnan, Sichuan, and Chongqing provinces.
• Temporal Scale: 2000–2018 (19 years).

Methodology and Data

• Models used:
  • Priestley-Taylor Jet Propulsion Laboratory (PT-JPL) model (for ET simulation and partitioning)
  • Sen + Mann–Kendall (MK) trend analysis
  • Multiple Regression Analysis (MRA)
  • Partial Least Squares Structural Equation Modeling (PLS-SEM)
• Data sources:
  • Remote Sensing: Global Land Surface Satellite (GLASS) LAI product, MODIS vegetation index product (MOD13A3), China Land Cover Dataset (CLCD).
  • Observation/Reanalysis: Global Land Evaporation Amsterdam Model (GLEAM) version 4.2 ET dataset (for validation), China Meteorological Forcing Dataset (CMFD v2.0) (for near-surface air temperature, precipitation, downward shortwave radiation, downward longwave radiation, relative humidity).

Main Results

• Vegetation restoration significantly enhanced total ET (+0.44 mm/a), interception evaporation (ETi, +0.22 mm/a), and soil evaporation (ETs, +0.37 mm/a).
• Canopy transpiration (ETc) exhibited a marginal decrease (–0.08 mm/a) due to vegetation restoration, indicating trade-offs in water allocation and potential water stress.
• Spatially, vegetation-driven increases dominated across 62.36% (ET), 59.01% (ETs), and 59.19% (ETi) of the karst region. ETc increases were concentrated in northern areas (>80 mm/a; 3.45% coverage).
• Radiation (Rad) was the primary driver of ET variations, dominating (>50% contribution) in 66.45% of the region.
• Temperature (Tem) controlled ET dynamics across 44.02% of the area, exhibiting the most extensive spatial dominance.
• Relative humidity (RH) showed complex drought-mediated dual effects, promoting ETi while suppressing ETc.
• Precipitation (Pre) exerted the weakest direct influence at regional scales, although it was the second dominant factor for ETc (22.44%).
• The PT-JPL model showed good agreement with GLEAM ET data (R² = 0.65, RMSE = 60.63 mm/a).

Contributions

• Quantified the synergistic and competing effects of vegetation restoration and climate change on ET and its components in the fragile karst region of Southwest China.
• Systematically elucidated the driving mechanisms of climate and vegetation changes on regional ET dynamics and its component variations using a dual-scenario PT-JPL model, trend analysis, multiple regression, and structural equation modeling.
• Provided critical insights for sustainable water resource management and vegetation allocation strategies in karst and analogous fragile ecosystems globally, particularly in the context of "engineering-induced water scarcity."
• Revealed that vegetation restoration, while increasing total ET, can lead to a marginal decrease in canopy transpiration (ETc), suggesting potential water stress and trade-offs in water allocation.

Funding

• General Fund of Key Laboratory of the Evaluation and Monitoring of Southwest Land Resources (Ministry of Education) (No. TDSYS202307)
• National Natural Science Foundation of China (No. 42477522)
• Key R&D Plan of Shaanxi Province (No. 2024SF-YBXM-621)
• Inner Mongolia Academy of Forestry Sciences Open Research Project (No. KF2024MS04)

Citation

@article{Zhang2025Synergistic,
  author = {Zhang, Geyu and Shen, Qiaotian and Wang, Zijun and Li, Hao and Wang, Zongsen and Xue, Tingyi and Wang, Dangjun and Shi, Haijing and Liu, Yangyang and Wen, Zhongming},
  title = {Synergistic Regulation of Vegetation Greening and Climate Change on the Changes in Evapotranspiration and Its Components in the Karst Area of China},
  journal = {Agronomy},
  year = {2025},
  doi = {10.3390/agronomy15102375},
  url = {https://doi.org/10.3390/agronomy15102375}
}