Abstract:[Objective] By studying the effect of conversion of forest to arable land on the abundance, diversity and structure of soil alkaline phosphatase gene encoding bacterial community, to provide basic data of soil microbial diversity, for sustainable land use. [Methods] The abundance, diversity and structure of soil alkaline phosphatase gene encoding bacterial community were investigated using real-time fluorescence quantitative PCR (qPCR) and high-throughput sequencing. Combining the determination and statistical analysis of soil chemical properties, relationships among the soil alkaline phosphatase gene encoding bacterial community abundance, Shannon diversity and soil chemical properties were also evaluated, as well as the key driving factors affecting community structure. [Results] After the forest land was reclaimed as arable land, long-term fertilization led to acidification of the soil, the pH dropped from 5.58 to 4.72, and the soil available phosphorus increased from 2.49 mg/kg to 49.3 mg/kg. Correspondingly, the soil alkaline phosphatase gene encoding bacterial community abundance and diversity significantly decreased with the conversion of forest to arable land. Based on species classification of alkaline phosphatase-encoding gene sequence, Proteobacteria, Cyanobacteria, Planctomycetes, Actinobacteria, Firmicutes and Verrucomicrobia were the dominant phyla, and the relative abundance of Cyanobacteria in forest significantly higher than that in arable land. The relative abundance of Bradyrhizobium and Bacillus in arable land were significantly higher than that in forest, while significantly higher relative abundance of Mesorhizobium, Pseudomonas, Chlorogloea, Gemmata, Phormidesmis and Pseudolabrys was found in forest. The structure of soil alkaline phosphatase gene encoding bacterial community was significantly affected by the land-use change. The abundance and Shannon diversity of soil alkaline phosphatase gene encoding bacterial community were significantly positively correlated with pH, but significantly negatively correlated with the soil available phosphorus, total phosphorus, nitrate nitrogen (NO3-) and ammonium nitrogen (NH4+), the soil available phosphorus is the most affected among these factors. The application of inorganic phosphate fertilizer caused the degradation of organophosphorus decomposition ability of soil bacterial community containing alkaline phosphatase. [Conclusion] The soil available phosphorus and pH changed by land-use change and long-term fertilization cause the alteration of the abundance, diversity and structure of the soil alkaline phosphatase gene encoding bacterial community under the coordinated driving of other physical and chemical factors.
