Replacement of plant communities altered soil bacterial diversity and structure rather than the function in similar habitats of the Yellow River Delta, China

Convergent evolution in plants has important roles in understanding the coexistence of species and the con-struction of communities in the same habitat. However, evidence that determines whether this phenomenon also occurs in soil bacteria is lacking. In this study, the communities of Suaeda salsa, Phragmites australis, and Tamarix chinensis on the same succession sequence in the supratidal habitat of the Yellow River Delta are taken as research objects. 16S rRNA high-throughput sequencing technology was used to test the diversity, structure, and function of rhizosphere soil bacteria. Result shows that the diversity of bacteria increases in the order of S. salsa < P. australis < T. chinensis. This finding may be related to the improvements of litter inputs, root exudates, and the change of soil physicochemical properties with the replacement of plant communities. At the phylum level, four out of eight bacterial phyla, mainly explained by pH (58.6 %), organic matter (57.7 %), moisture content (57.6 %), total carbon (40.8 %), and available potassium (39.5 %) of soils, changed significantly with the replacement of plant communities (p < 0.05). At the genus level, the dominant bacteria in different communities were clearly distinguished, but their metabolic function remains unchanged, indicating that convergent evolu-tion also exists in the bacterial world. In summary, bacteria tend to make full use of limited resources by increasing niches rather than increasing the intensity of metabolic activities in similar habitats.