Jia et al. (2025) Post-conversion vegetation restoration: PRE and VPD dominated the NDVI changes on the Loess Plateau

Identification

• Journal: Journal of Environmental Management
• Year: 2025
• Date: 2025-09-27
• Authors: Hao Jia, Biqing Tian, Xiaoyan Song, Wenyi Sun, Xingmin Mu
• DOI: 10.1016/j.jenvman.2025.127434

Research Groups

• State Key Laboratory of Soil and Water Conservation and Desertification Control, College of Soil and Water Conservation Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
• Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Yangling, Shaanxi, China
• Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling, China

Short Summary

This study investigated the response of vegetation greenness (NDVI) to climatic factors and soil moisture on the Loess Plateau from 2000 to 2020, finding that precipitation was the dominant promoter of vegetation growth, while vapor pressure deficit (VPD) was the primary constraint.

Objective

• To investigate the response of the normalized difference vegetation index (NDVI) during the growing season (May–October) from 2000 to 2020 on the Loess Plateau of China to monthly precipitation (PRE), temperature (TEM), vapor pressure deficit (VPD), and 0–1 m soil moisture (SM) in the context of the "Grain-for-Green" Program.

Study Configuration

• Spatial Scale: Loess Plateau, China.
• Temporal Scale: 2000 to 2020, specifically the growing season (May–October).

Methodology and Data

• Models used: Structural Equation Modeling (SEM), Partial correlation analysis, Lagged correlation analysis.
• Data sources: Normalized Difference Vegetation Index (NDVI), monthly precipitation (PRE), monthly temperature (TEM), monthly vapor pressure deficit (VPD), and 0–1 m soil moisture (SM).

Main Results

• NDVI significantly increased during July–August at a rate of 0.006–0.007 per year.
• The area with NDVI < 0.3 decreased from 28.2 % to 6.2 %, while the area with NDVI > 0.6 expanded from 14.4 % to 62.8 %.
• In the central restoration region, vegetation showed positive correlations with precipitation and soil moisture at 2–3 month lags, but negative correlations with temperature (3-month lag) and VPD (no lag).
• In the densely vegetated southern region, only temperature showed a positive correlation, with all other factors exhibiting negative correlations.
• Structural Equation Modeling (SEM) identified precipitation as the dominant factor promoting vegetation growth (average path coefficient of 0.67).
• Rising temperature initially enhanced growth but became a suppressing factor as plants developed and temperatures increased.
• VPD was the primary constraint on vegetation growth (average path coefficient of 0.21).
• Soil moisture had a relatively weak inhibitory effect on vegetation.

Contributions

• Provides important theoretical support and practical implications for vegetation restoration and water resource management in arid and semi-arid regions.
• Quantifies the relative importance and lagged effects of climatic factors and soil moisture on vegetation greenness changes on the Loess Plateau following large-scale restoration efforts.

Funding

• Not specified in the provided text.

Citation

@article{Jia2025Postconversion,
  author = {Jia, Hao and Tian, Biqing and Song, Xiaoyan and Sun, Wenyi and Mu, Xingmin},
  title = {Post-conversion vegetation restoration: PRE and VPD dominated the NDVI changes on the Loess Plateau},
  journal = {Journal of Environmental Management},
  year = {2025},
  doi = {10.1016/j.jenvman.2025.127434},
  url = {https://doi.org/10.1016/j.jenvman.2025.127434}
}