Microbial resistance and persistence increase during estuarine succession and promote nutrient accumulation

Understanding how belowground ecosystems maintain stability in the face of environmental change remains a fundamental challenge in ecology. In this study, we examined both the topological resistance and temporal persistence of microbial communities, including bacteria, fungi, and protists, across tidal and non-tidal zones in the Yellow River Delta (YRD), sampled across four seasons. Using amplicon sequencing, combined with molecular ecological networks and the iDIRECT framework, we found that succession from tidal wetland to non-tidal land significantly enhanced microbial diversity (average increase: 44.0 %) and temporal persistence (373.0 %), while simplifying network complexity (a 36.3 % reduction in intra- and inter-domain associations). Non-tidal land exhibited higher topological resistance and temporal persistence, indicating stronger ecological memory and reduced turnover. Multivariate analyses, including the Mantel test and structural equation modeling (SEM), confirmed that these changes were primarily driven by decreases in environmental stress (e.g., lower salinity and pH) and increases in soil nutrient accumulation ( i.e. , soil organic matter and soil nitrogen). These results suggest that microbial relationships played critical roles in the succession of the estuary landscape. Our findings provide a practical basis for using microbial network stability as an indicator for ecological monitoring and management in various ecosystems.