Seasonal Dynamics of Rhizosphere Soil Microbial Abundances and Enzyme Activities under Different Vegetation Types in the Coastal Zone, Shandong, China

Microbial community responses to alternative management may be indicative of soil quality change. In this study, soils were collected from research plots over one year. The rhizosphere soils were studied by measuring microbial abundance (bacteria, fungi, actinomycetes, and ammonifiers), enzyme activities (invertase, catalase, urease, and phosphatase), and their relationship. Rhizosphere microbial abundance of different plant species varied greatly across seasons. The rhizosphere environment generated by Phragmites australis and Echinochloa crus-galli is suitable for microbial growth. In addition, the significant differences in rhizosphere enzyme activities of different plant species across seasons were also observed. There was a significant linear correlation between rhizosphere soil enzyme activities and microbial abundances except for between bacteria and catalase and between fungi and urease, but no such significant relationship was found between all rhizosphere soil microbial abundance and phosphatase except between fungi and acid phosphatase. We concluded that different plant species in coastal areas have different rhizosphere soils, due to the impact of the different root exudates and plant residues of the microbial properties