Editorial: Microbial ecological and biogeochemical processes in the soil-vadose zone-groundwater habitats, volume III

Microorganisms are pivotal in regulating biogeochemical cycles and performing critical functions in soil, vadose zone, and groundwater habitats (Chi et al., 2022;Song et al., 2024). Microbial communities in these habitats respond and shift rapidly to adapt to environmental changes (Li et al., 2024;Liang et al., 2023). Both biotic and abiotic conditions shape microbial composition and activity, which in turn affect key ecosystem processes (Li et al., 2022;Chi et al., 2025). Environments such as natural wetlands, landfills, composts, vadose zones, and saturated aquifers are all parts of the broader soil-vadose zone-groundwater. The aim of this volume is to collect innovative research that advances our understanding of microbial ecological processes in these habitats and explore the possibilities of developing sustainable environmental management. Nine articles included in this Research Topic have undergone rigorous peer review and have been selected for their contributions to these areas of study.Wang et al. revealed the pronounced functional disparities among Artemisia scoparia, Aeluropus sinensis and Suaeda salsa communities. The herbaceous plant community significantly affected the physicochemical properties of the 0-20 cm soil layer. Suaeda salsa, Artemisia scoparia, and Phragmites australis communities were the most effective communities for comprehensive soil quality improvement on Yellow River Island. Chi et al (a). demonstrated that the ultra-high-temperature (UHT) composting bioaugmented with a high-dose microbial inoculum (CT2) could achieve highly efficient co-remediation of heavy metals and antibiotics in livestock manure. This process significantly promoted the passivation of Cu and Zn and achieved near-complete degradation (>99.4%) of tetracycline (TC), oxytetracycline (OTC), and chlortetracycline (CTC). Chi et al (b). found that the addition of small particle activated carbon (S-AC, 2-4 mm) could increase the pH value and organic matter of organic fertilizers, and reduce the cation exchange capacity (CEC) value, but had no significant effect on the electrical conductivity (EC) value. S-AC had high mechanical strength (compressive Despite these varied conditions, microbial communities remained adaptable. The uranium concentration was the primary driver of microbial community structure. The simpler, less interconnected microbial networks were present under high uranium conditions, while intermediate and relatively low uranium levels supported more complex assemblages. The stochastic processes such as dispersal limitation dominated community assembly in high-uranium environments, whereas deterministic processes, including both heterogeneous and homogeneous selection, were more significant in those environments with moderate to low uranium concentrations. The authors conclude that at lower uranium concentrations cooperation among microbial taxa may prevail, while at higher concentrations, microbes may shift to a competitive "fight for their own" strategy.Wang et al. unveiled that the compositions and diversities of abundant and rare subcommunities were notably altered in crab-bioturbated sediments. The crab bioturbation substantially modified the interaction patterns of rare bacteria, whereas its influence on abundant bacteria was comparatively minor. The assembly processes of abundant subcommunities were primarily influenced by stochastic processes, while rare subcommunity assemblies were collectively shaped by both stochastic and deterministic processes. We think that all accepted articles in this Research Topic will provide new knowledge on microbial processes in soil-vadose zone-groundwater habitats.Author contributions: All authors listed have made a substantial, direct, and Li, H., Liang, S., Chi, Z., Wu, H., and Yan, B. (2022). Unveiling microbial community and function involved in anammox in paddy vadose under groundwater irrigation. Sci. Total Environ. 849, 157876.Chi, Z., Li, W., Zhang, P., and Li, H. (2025). Hydraulic retention time (HRT) extension and nitrate addition mitigate Se(VI) inhibition and enhance selenium removal in constructed wetlands: Potential role of nitrate and Fe/Mn pumps.Bioresource Technol. 425, 132328.