As an important means of curbing soil degradation, afforestation has a profound impact on regional soil properties and quality. However, it is still unclear regarding how to conduct a systematic assessment of soil properties and soil quality and the impact of vegetation characteristics and plant functional traits in leguminous plantations with different afforestation years in drylands. Therefore, we investigated the vegetation characteristics and determined the functional traits of leaves and roots and the soil physicochemical properties of Caragana korshinskii plantations with 13, 35, and 55 years. The results showed that tree height; crown diameter (CD); root dry matter content; root water content; soil clay, silt, and sand contents; bulk density (BD); soil water content; soil organic carbon (SOC); total nitrogen (TN); available nitrogen; total phosphorus (TP); available phosphorus (AP); and soil quality index (SQI) changed significantly with an increase in afforestation years. Although the specific leaf area did not show a significant variation, it had a significant negative effect on soil properties and SQI, except for soil sand and BD. Soil sand and BD decreased with the afforestation succession, but the succession pattern of soil clay, silt, SOC, TN, TP, and AP was 13 years < 35 years < 55 years, and SQI increased from 0.20 (13 years) to 0.77 (55 years). This indicated that long-term legume afforestation led to the transformation of soil texture from silty loam to silt and significantly improved the soil properties and quality in the study area.

《地球科学》(ISSN 1000-2383;CN42-1874/P) (原刊名《地球科学——中国地质大学学报》ISSN 1000-2383;CN42-1233/P)，创刊于1957年，是由教育部主管、中国地质大学主办的综合性地学学术理论期刊，月刊，2015年改名为《地球科学》,她以反映中国地质大学教学与科研最新的、高水平的基础地质、应用地质、资源与环境地质及地学工程技术研究成果为主要任务。

Soil water-heat plays a significant role in land surface processes and has an impact on almost all ecosystem processes and functions practically. However, the controls of soil water-heat by environmental factors remain to be elucidated. In this study, relationships of soil water-heat with environmental factors in the Qilian Mountains, China were quantified using data obtained from a regional soil survey during the summer of 2019. Our results showed that soil water content (SWC) depicted a trend of being high in the east and low in the west, and soil temperature (ST) showed an opposite trend. The PLSPM suggested that topography, climate, vegetation, and soil properties had a similar control on SWC, with total effect values of 0.41, -0.34, 0.33, and -0.47, respectively. Soil properties and vegetation directly influenced SWC, topography indirectly influenced SWC by altering climate, and climate directly influenced SWC and indirectly through vegetation. Conversely, the factor controlling ST was topography (total effects = 0.39), which influenced ST directly and positively. The VPA indicated that the combination of environmental variables explained 64.26% of the variation in SWC and 27.69% of the variation in ST.