img

Wechat

Adv search

Journal of Desert Research ›› 2025, Vol. 45 ›› Issue (5): 328-337.DOI: 10.7522/j.issn.1000-694X.2025.00227

Previous Articles    

Moisture influencing factors on semi-fixed sand dunes in southeast edge of Tengger Desert

Shurui Yang1(), Tian Yang2, Lu Zhang2, Dinghai Zhang2(), Haidi Qi2   

  1. 1.Gansu Minqin Liangucheng National Nature Reserve Management and Protection Center,Minqin 733399,Gansu,China
    2.Center for Quantitative Biology,College of Science,Gansu Agricultural University,Lanzhou 730070,China
  • Received:2025-05-23 Revised:2025-07-23 Online:2025-09-20 Published:2025-09-27
  • Contact: Dinghai Zhang

Abstract:

Soil moisture is a key driver of the sand fixation vegetation patterns and processes in arid sandy regions, exhibiting significant variability across different microtopography types in the sandy area. This study focuses on soil moisture in the semi-fixed dunes on the southeastern edge of the Tengger Desert, analyzing its distribution characteristics across four microtopographic types: windward slope, leeward slope, the top of dune, and the bottom of dune. A partial least squares structural equation model (PLS-SEM) was employed to determine the influence paths of topography, shrub, and herbaceous factors on soil moisture. Additionally, an interpretable machine learning model (SHAP) was used to identify the key factors influencing soil moisture among topographic and vegetation factors and elucidate their mechanisms. The results indicate that the surface soil moisture at the bottom of dune is highest, at 1.21%, while the mid- and deep-layer soil moisture on the leeward slope reaches 2.25% and 2.43%, respectively. As herbaceous coverage increases and slope direction changes, soil moisture at different depths first decreases and then increases. Surface soil moisture shows a trend of decrease followed by increase as height difference changes, with a threshold of 3 meters in elevation. The soil moisture in the middle and deep layers also exhibits a trend of increasing and then decreasing with the rise in biomass and shrub cover, with thresholds of 30 g and 40%, respectively.

Key words: Tengger Desert, semi-fixed dune, soil moisture, topography-vegetation factor, structural equation model, SHAP model

CLC Number: