Bacterial, fungal and protist communities affect differentially in succession stage of karst soil

Karst soil microbial communities are major drivers of cycling of soil nutrients that sustain plant growth and productivity. Yet, a holistic understanding of the impact of different succession stage on the karst soil microbiome is still pooly understood. Here, we used a field experiment to investigate the loog-term consequences of changes in succession stage: rocky desertification(RD), grassland(GL), shrubs(SH), forest plantation(FP) and natural forest(NF) based on plant frequency on bacteria, protist and fungal communites. We showed that the shannon index of bacteria and fungi were higher in NF compared to GL, while protist shannon index was higher in SH that GL. The bacterial simpson_e index in NF and PF were higher than that in GL, SH and RD, howerer fungal and protist simpson_e index were similar across the five succession stages. Significant differences were observed in observed outs and phylogenetic diversity index in NF, SH were higher than GL, RD for fungi and protist, whereas bacterial observed outs and phylogenetic diversity index were relatively similar in five succession stage. The five succession stage differed markedly in the compositions of bacterial, fungi and protist communities. In bacterial, dominant phyla were Actinobacteriota, Proteoprotist, Acidobacteriota. Protist communities were dominated by Phragmoplastophyta, Arthropoda phyla. Regarding protist taxa, the dominant phyla were Ascomycota and Basidiomycota. Our findings provided evidence indicating that the microbial community compositions of RD, GL, SH, PF, and NF have their respective characteristics. These characteristics stem from differences in vegetation coverage, plant debris, root formation and other factors, leading to changes in the diversity and taxonomic group of bacteria, fungi and protists at different successional stages. Overall, this study provides a comprehensive perspective, showing the differences in microbial communities at different successional stages in karst soil.