Bacterial Community Changes in Early-Stage Engineering Simulation of Red Mud/Phosphogypsum-Based Artificial Soil...

Preparing red mud/phosphogypsum-based artificial soils for vegetation restoration is promising. However, how artificial soil develops during vegetation restoration is unclear, especially regarding the relationship between the bacterial community and the development of artificial soil. The bacterial community changes in the early-stage engineering simulation of red mud/phosphogypsum-based artificial soil vegetation restoration were analyzed for the first time in this paper. The results showed that the structure of the bacterial community was simple at the beginning, mainly consisting of Proteobacteria, Firmicutes, and Bacteroidota, with total abundances of 74.5% and 89.3% in the two plots, respectively. The richness, diversity, and evenness of the bacterial communities all significantly increased over time (p < 0.05), indicating that the compositions of the bacterial communities in artificial soils undergo constant development, adjustment, and optimization. There were good correlations between bacterial communities and environmental factors (e.g., pH, W_H2O, OM, TN, TK, AK, TP), which generally reflected the significant synergistic development and interaction between the quality of the soil environmental and bacterial communities. There were complex dynamic changes in the functions of the bacteria during the development of artificial soils, which were mainly reflected in the decline in the abundances of chemoheterotrophy, aerobic chemoheterotrophy, and animal parasites or symbionts, but there was an increase in the abundances of phototrophy, cyanobacteria, and dark sulfide oxidation. This reflects the highly active physiological and biochemical reaction functions of bacterial communities in the development of artificial soils, which is of great significance for continuously enhancing the fertility quality and ecological attributes of artificial soils.