AMarkov-basedmodel for predicting the development trend of soil microbial communities in saline-alkali land in Wudi County

摘要

In October 2015, different salinity soils were collected in the coastal area of Wudi, Shandong,China. The soil microbial community composition, soil catalase, urease activity, and soil physicochemicalproperties were studied. The results showed that Nitrospira was dominant in thebacterial community, and it was the most related to total potassium. Cladosporium and Fusariumaccounted for thedominant fungal community, andurease, totalnitrogen,andCladosporiumwerethemost relevant. At the same time, urease and Fusarium are the most relevant. The species compositionof bacterial and fungal communities in the top soil of each saline-alkali soil is the mostabundant, and the degree of homogeneity is high. The activities of catalase in soils with heavy,moderate, and light salinity were 3.52 to 4.56, 3.08 to 4.61, and 5.81 to 6.91mL•g-1, respectively.Catalase activity all of them are characterized by gradual increase with soil depth; soil total potassiumis directly related to catalase, pH, organic matter, total nitrogen, and total phosphorus areindirectly related to catalase by total potassium. The urease activities of the saline-alkalinity soilswere 0.04-0.52, 0.08-1.07, and 0.27-8.21 mg•g-1, respectively, and the urease activity graduallydecreased as the soil depth increased. Small trend; soil total nitrogen is directly related to urease,pH, organic matter and total potassium are indirectly related to urease through total nitrogen.TheCCAranking showedthat totalphosphorushadthegreatest impactonbacterial communities,while urease had the greatest impact on the fungal community.