The eco-hydrological threshold for evaluating the stability of sand-binding vegetation in different climatic zones

Abstract

Soil moisture dynamics are a determinant of the sustainable development of artificial sand-binding vegetation, which directly prevents and controls desertification and sand hazards, such as the sand burial of farmlands and pastures. How to maintain the stability of sand-binding vegetation is a challenge for ecologists and land managers. An eco-hydrological model coupling the dynamics of sand-binding vegetation cover and soil moisture was used to explore the effect of a stochastic daily precipitation regime on soil moisture and vegetation cover after the establishment of sand-binding vegetation. The simulation results indicate that herbaceous vegetation cover, woody vegetation cover and soil moisture increase nonlinearly with increasing annual rainfall. Specifically, herbaceous vegetation cover first increased and then decreased with increasing annual rainfall. Woody vegetation cover increased by a power-law function within the total community cover, and soil moisture increased exponentially. The eco-hydrological thresholds in different climatic zones and in typical revegetated sandy desert regions of China were determined using an eco-hydrological model. These indexes will not only help to promote dryland ecosystem management and maintain the sustainability of wind-breaks and sand-binding benefits but will also provide a quantifiable reference standard for vegetation recovery and reconstruction in sandy areas in the future.