三江源区不同覆被类型高寒草甸土壤水分变化特征

Soil moisture is the material foundation for plant growth and reproduction; therefore, understanding its dynamic properties is critical for local water management and vegetation restoration. The study area of this research was the alpine meadows in the Three River Source Region, and the study combined field surveys and laboratory experiments to analyze the annual, seasonal, and daily dynamic characteristics of soil moisture in alpine meadows under different cover types and explore the influence of vegetation and soil factors on soil moisture changes. The findings revealed that: (1) In 2022, when there was less rainfall and temperatures were higher, the soil liquid water content in different areas decreased by 1% to 18% compared with previous years; the soil unfrozen water content was higher in summer and fall than in winter and spring; and the highest monthly average water content of various sites occurred in October (0.495 m3 m3) and the lowest value was in January (0.038 m3 m3); the daily variations in the soil liquid water content in March and December were larger, ranging from 0.11 to 0.20 m3m3 and 0.07 to 0.16 m3m3, respectively. (2) Mildly and highly degraded alpine meadows (YG4) and native alpine meadows (YG5) have greater vegetation cover and lower bulk density, resulting in greater soil water content and less variance. (3) Artificial grassland did not promote soil water retention owing to its high water consumption, single species, and low soil fertility. The results of the study can provide a reference for the restoration and management of alpine meadow ecosystem in the Three-River Source Region.