Rehabilitation following open-cast mining aims to build a long-term functional and sustainable soil cover for a stable landscape development. The objective of this study was to assess changes in soil recovery of rehabilitation performed at different times (1980, 1998, 2009, 2016, 2017) measured as soil hydraulic and mechanical properties (shear stress) at an open-cast Yallourn mine site in south-east Australia (Victoria) in 2021. Soil hydraulic properties (SHP) were determined using the extended evaporation method and the water retention and hydraulic conductivity curves were fitted using the van Genuchten-Mualem model. The vane shear tests were performed at two depths (0-8 and 10-18 cm) combined with soil water content measurements. The results of the SHP showed a shift in the soil water retention curve when comparing 1980 and 2017 sites. While the saturated water content i.e., total porosity was the same, the saturated hydraulic conductivity (Ks) decreased from 36.7 to 1.02 cm day-1, respectively. This was mostly connected to the textural pore size distribution, as large differences in clay and sand content among the sites were observed. The vane shear test showed also large differences with rehabilitated sites indicating a larger variation compared to the reference site (exception 2016 site) and having generally higher shear resistances. The observed small-scale heterogeneity of the rehabilitated soils is most likely explained by soil heterogeneity and disturbance due to excavation activities and rehabilitation as well as availability of uniform soil material. Inevitable heterogeneity of the soil hydraulic and mechanical properties should be taken into consideration during the design and construction of various landforms as well as when implementing soil monitoring schemes.

By altering the physical properties of soil through root activity, plants can act as important agents in affecting soil hydrothermal properties. However, we still know little about how plant roots regulate these properties in certain ecosystems, such as alpine meadows. Thus, we studied the influence of roots on soil hydrothermal properties in the Qinghai-Tibet Plateau (QTP). Root biomass as well as soil physicochemical and hydrothermal properties were examined at a depth of 0-30 cm at three study sites in the QTP. The relationship between root biomass and saturated soil hydraulic conductivity (K-s) was examined, as was the applicability of common soil hydrothermal properties models to the alpine meadow system. Results revealed that approximately 91.10%, 72.52%, and 76.84% of root biomass was located in the top 0-10 cm of soil at Maqu, Arou, and Naqu, respectively. Compared with the bulk soil, the water-holding capacity of rhizosphere soil was enhanced by 20%-50%, while K-s was decreased by at least 2- to 3-fold. The thermal conductivity (lambda) of rhizosphere soils was lower than that of the bulk soil by 0.23-0.82 W m(-1).K-1 on average. Lastly, soil hydrothermal properties models that do not explicitly consider root effects overestimated the Ks and lambda in the rhizosphere soil of these systems. Overall, our results revealed distinctive differences in soil hydrothermal properties between the rhizosphere soil and the bulk soil in the QTP. This research has important implications for future modeling of soil hydrothermal processes of alpine meadow soils.