海南岛老爷海人工红树林湿地固碳细菌群落特征研究OA

To investigate the community structure of carbon-fixing bacteria and their environmental driving mechanisms in the artificial mangrove wetlands of Laoyehai Lagoon,Wanning City,Hainan Province,we systematically analyzed the soils from bare tidal flats and mangrove areas using high-throughput sequencing and quantitative real-time PCR(qPCR).The results showed that the gene abundance of carbon-fixing bacteria in mangrove soil was generally higher than that in bare tidal flats,except for individual bare tidal flat sampling sites(e.g.,GT2).The Chao1 species richness index indicated the superior microbial species richness in mangrove areas,while the Simpson diversity index,Shannon-Wiener diversity index and Pielou evenness index all exhibited spatial heterogeneity.The bare tidal flats far from the ocean are higher than the mangrove areas,whereas mangrove areas close to the ocean had higher values than bare tidal flats.The dominant carbon-fixing phyla were mainly Pseudomonadota and Cyanobacteriota,and the proportions of dominant genera were Cupriavidus(16.11%～24.66%),Thiobacillus(10.39%～12.77%)and Sulfuricaulis(9.13%～10.54%).Additionally,there were 29 marker differential species between the two habitats,which belonged to α-Proteobacteria,β-Proteobacteria and γ-Proteobacteria.Principal Coordinate Analysis(PCoA)combined with Analysis of Similarities(ANOSIM)and Permutational Multivariate Analysis of Variance(PERMANOVA)tests revealed significant differences in the community structure of wetland carbon-fixing bacteria.The differences between groups were greater than those within groups.Redundancy analysis(RDA)demonstrated that the community structure of carbon-fixing bacteria the bare tidal flat habitat was mainly driven by factors such as organic carbon,easily oxidizable organic carbon,silt,fine sand,organic matter,total nitrogen,total phosphorus,clay,water content and pH,while the mangrove areas was mainly driven by organic carbon,clay,easily oxidizable organic carbon,organic matter,total phosphorus,silt,fine sand and water content,among them soil particle size and organic carbon were the common dominant factors in the two habitats.The results of this study confirmed that artificial planting of mangroves can reshape the community structure and diversity of carbon-fixing bacteria by improving soil physicochemical properties,thus demonstrating the important application potential and practical value in coastal wetland ecological restoration and carbon sink function enhancement.