Catabolic Activity and Structural Diversity of Bacterial Community in Soil Covered by Halophytic Vegetation

The catabolic activity and structural diversity of soil bacteria covered by five different halophytic vegetation types in the Yellow River Delta affected by long-term salinization were studied using Biolog-Eco technology. The result showed that soil quality, the diversity, and catabolic activity of the bacterial community of mildly salt-tolerant vegetation (Imperata cylindrical (L.) Beauv. and Apocynum venetum L.) were significantly higher than those of the bacterial community of highly salt-tolerant vegetation (Suaeda salsa (L.) Pall., Aeluropus sinensis (D.) Tzvel.), while these values were lowest for bacterial communities in bare land. The operational taxonomic units (OTUs) and diversity indexes of soil bacteria covered by Aeluropus sinensis were higher than those of soil bacteria covered by other types of vegetation, while those of soil bacteria covered by bare land were lowest. Principal component analysis (PCA) of the carbon source utilization capacity of the soil bacterial communities showed that organic acids, polymers, and amino acids were sensitive carbon sources that enabled study of the diversity of carbon metabolic functions in soil bacterial communities. And redundancy analysis (RDA) showed that D-galacturonic was significantly positively correlated with Verrucomicrobia, which further demonstrated the effect of organic acid carbon sources on metabolic functional diversity of soil bacterial communities in the Yellow River Delta.