Study on the relationship between topological characteristics of vegetation ecospatial network and sand fixation function in the Mongolian Plateau

Abstract

The spatial structure of vegetation plays a pivotal role in determining the sand fixation function of ecosystems. However, the interaction between vegetation spatial structure at the regional scale and its sand fixation function remains insufficiently understood. Addressing this gap is essential for developing effective strategies to mitigate soil erosion, combat desertification, and enhance ecosystem stability in arid and semi-arid regions. This study investigates the Mongolian Plateau, a region highly vulnerable to wind erosion. Using the minimum cumulative resistance (MCR) model and complex network theory, the regional-scale vegetation structure was abstracted into a vegetation ecospatial network (VEN), and its topological characteristics were analyzed. The revised wind erosion equation (RWEQ) was then applied to estimate soil wind erosion and evaluate vegetation's sand fixation function for 2020. Correlation analysis was conducted to explore the relationships between VEN topological indicators, vegetation-driven sand fixation, and regional wind erosion. The results revealed the 2020 Mongolian Plateau VEN as a scale-free small-world network with strong heterogeneity. Wind erosion modulus of the Mongolian Plateau in 2020 amounted to 33.79 t hm⁻², while vegetation sand fixation amount reached 48.68 t hm⁻². Most VEN nodes exhibited high sand fixation function. Node sand fixation function exhibited a strong positive correlation with PageRank and a substantial positive correlation with degree and betweenness centrality. These findings can provide insights into optimizing vegetation patterns and enhancing sand fixation function.