Search

[Objective] To explore the water use characteristics of typical plants under different ecological measures at the waste dump, improve plant water use efficiency, and accelerate the ecological restoration process in mining areas. [Methods] Six ecological measures (control, inoculation, green fertilizer, inoculation+green fertilizer, inoculation+weathered coal, inoculation+green fertilizer+weathered coal) were implemented at the waste dump of the Heidaigou Coal Mine to treat Amorpha fruticosa. Stable isotopes of hydrogen and oxygen in water were combined with other techniques. [Results] (1) The soil moisture content of the waste dump was 3% to 9%, which was lower in the 0-30 cm and 70-100 cm soil layers, and higher in 30-70 cm soil layer. (2) Amorpha fruticosa obtained water from precipitation and soil. The soil water undergoes significant fractionation processed in the 0-30 cm soil layer, and exhibited significant differences among different ecological measures, with the green fertilizer treatment showing the highest and inoculation+green fertilizer treatment being the lowest. (3) Significant differences existed in the water use characteristics of Amorpha fruticosa under various ecological measures. The inoculation treatment exhibited a higher water use ratio of 53.4% in the 50-100 cm soil layer; The green fertilizer treatment mainly utilized the soil water in the surface layer (0-20 cm), which was 42.6%; The treatment of inoculation and green fertilizer had a relatively uniform proportion of soil water use in each layer. [Conclusion] The inoculation + green fertilizer treatment optimized the water use characteristics of Amorpha fruticose plants, increased the utilization ratio of surface and deep soil water, and can be used as an ecological reclamation measure for waste disposal sites, which promoted the ecological recovery rate and effect of arid mining areas in the western region.

[Display omitted] • The proportion and OC content of large aggregates were affected by vegetation types. • The direction of carbon flows was from small aggregates to silt + clay size classes. • Tree plantation slowed carbon flows of aggregates. • Roots are more likely to be the starting point of carbon flow at 15–30cm depth. The vegetation restoration of land post‑mining can promote soil structure development and increase organic carbon storage. The response of soil carbon sequestration pathways to different recovery modes is poorly understood, especially in soils of reclaimed surface-mine areas. Here, long-term carbon dynamics were characterized by examining aggregate-associated carbon contents and carbon flow pathways following vegetation restoration of reclaimed land near a surface mine. Six long-term restoration areas were represented by Populus alba trees, Amorpha fruticosa shrubs, and grassland. During the long-term restoration process the contribution of aggregates to SOC (12.5 to 46.1%), δ13C values (-25.91 to –23.65‰) and percentages of particulate organic carbon in large soil aggregates of tree plantations showed the maximum increase and shrubland showed the minimum. The direction of carbon flows was from small aggregates to silt + clay size classes, and tree plantations slowed the carbon flows of aggregates. With increasing soil depth, roots were more likely to be the starting point of carbon flow in aggregates. This analysis of the natural δ13C signature reveals the mechanism of organic carbon stabilization under long-term vegetation restoration near a surface mine in a semi-arid region. [ABSTRACT FROM AUTHOR]