Enhanced sediment microbial diversity in mangrove forests: Indicators of nutrient status in coastal ecosystems

Coastal ecosystems are increasingly threatened by nutrient imbalances and environmental degradation, which can compromise their stability and productivity. We analyzed the sediment characteristics, microbial community structures, and nutrient cycling across three habitats: mangrove forests, seagrass beds, and bare beaches. The physicochemical properties (including pH, total nitrogen (TN), phosphorus (P), and potassium (K)) of the sediment samples were analyzed, and the microbial diversity was assessed using high-throughput sequencing. Our findings indicated that the organic matter (OM), TN, and cation exchange capacity (CEC) of mangrove sediments were significantly higher than those of seagrass beds and bare beaches. The microbial community in mangroves was positively correlated with OM content and was more complex and stable than that in seagrass beds and bare beaches. MG potentially improved the abundance of k00059 and enzyme 1.1.1.100 in sediment bacteria and further increased sediment TN, OM, and CEC. This study indicates the importance of microbial diversity as a potential indicator of sediment and plant nutrient status, emphasizing the need for conservation efforts to preserve mangrove ecosystems.