基于流变学法探究植被恢复下土壤力学稳定性.

[Objective] This study is aiming to evaluate the dynamic evolution of soil microstructure stability during vegetation restoration on the Loess Plateau. Methods］ Soil samples from four stages of vegetation succession in the Ziwuling forest region were examined. Utilizing the amplitude sweep test method. soil shear strength and viscoelastic parameters were assessed under various matric potentials ((), --3 and 一10 kPa). Correlation analyses between these parameters and soil physicochemical properties were conducted. Results］ (1) Soil shear strength and viscoelasticity exhibited an increasing trend with advancing vegetation succession stages. attributed primarily to the increasing of soil organic carbon. exchangeable Ca'+ and sand content, along with reduced Na+ during vegetation recovery. This augmentation contributed to enhanced interparticle adhesion and frictional forces. (2) The soil shear strength parameter in creased with the decreasing of matric potential. Under low matric potential conditions. there was no significant correlation between soil shear strength parameters (G'i.ve、tn and t„u,x) and exchangeable Ca'+ and sand content. Under high matric potential conditions, soil shear strength parameters showed a significant positive correlation with exchangeable CaJ+ (p<().()5): while lve, rYj>, and G'yf exhibited significant positive correlations with sand content. (3) Soil viscoelastic parameters (7yj> and/z) showed a decreasing trend with declining matric potential. Particularly, under high matric potential conditions, these parameters exhibited a positive correlation with organic carbon content, which gradually attenuated with the decreasing of matrix potentiaL Viscoelastic parameters were negatively correlated with clay content under different matric potentials. (4) The overall mechanical stability of soil was positively correlated with soil Ca2+ at () kPa, negatively correlated with soil silt and K+ content at 一3 kPa, and positively correlated with clay content at 一1() kPa. _Conclusion] The changes and influencing mechanism of soil mechanical stability under different vegetation types and different matric potentials were revealed, which provided an important basis for understanding the evolution of soil characteristics in the process of vegetation restoration on the Loess Plateau, and also provided theoretical support for soil protection and ecological restoration in the future. [ABSTRACT FROM AUTHOR]