Liana species and fertilization shape rhizosphere bacterial communities in abandoned iron mines.

Climbing plants, with their vigorous root systems, strong adaptability, large biomass, and wide range of uses, hold great potential in mine soil restoration. To explore the ecological restoration effects of different liana species, the Longtie mining area in Longmen County, Huizhou City, Guangdong Province, China, was selected as the study site. Six liana species-Canavalia gladiata, Benincasa hispida, Pueraria montana, Mucuna pruriens, Ipomoea quamoclit, and Ormosia semicastrata were subjected to two treatments: fertilization and non-fertilization. The soil microbial diversity and community structure of the two treatments were analyzed using 16 S rRNA gene sequencing. The results showed that fertilization altered the diversity, composition, and structure of the microbial community. In terms of microbial diversity, the fertilized treatment had 1179 more bacterial ASVs (Amplicon Sequence Variants) than the non-fertilized treatment. After fertilization, Pueraria montana showed higher microbial abundance and diversity, with both Chao1 and ACE values exceeding 1200. In terms of microbial composition at the family level, the fertilized treatment had the highest relative abundance of Gemmatimonadaceae (18.01%), while the non-fertilized treatment had the highest relative abundance of Nitrosomonadaceae (15.93%). At the genus level, Anaeromyxobacter was the dominant genus, and Ramlibacter was the secondary dominant genus. Regarding the microbial community structure, distinct microbial communities were observed across different liana species, revealing pronounced heterogeneity and community differentiation.