Abstract: Artificial restoration is an essential measure for mangrove ecosystem conservation and recovery. One year after Kandelia obovata planting in the Bachimen Inner Bay restoration area (Fuding, China), sediment samples were collected at different depths. High-throughput sequencing was used to analyze bacterial community structure, assembly processes, and ecological functions during the early restoration stage. The results showed: (1) Gammaproteobacteria, Alphaproteobacteria, Anaerolineae, and Acidimicrobiia were the most diverse and abundant taxa; bacterial diversity showed no significant differences among depths, but community composition differed significantly (P = 0.037); (2) neutral model analysis indicated that stochastic processes dominated community assembly across depths; (3) co-occurrence network analysis revealed strong cooperative interactions, with the deepest layer showing the highest network stability; and (4) chemoheterotrophy, aerobic chemoheterotrophy, and fermentation were the predominant functions, and their abundances varied with depth. These findings improve our understanding of the early stage bacterial communities in restored mangrove sediments and provide a scientific basis for restoration and management practices.

Key words: Bacterial community structure, assembly mechanisms, ecological functions, early mangrove restoration, Illumina high-throughput sequencing