Effect of Different Land Use Types on the Diversity of Soil Bacterial Community in the Coastal Zone of Jialing River

Abstract

The purpose of this study was to clarify the differences in soil bacterial community diversity in different land uses in the coastal zone of the Jialing River and to provide theoretical reference for reasonable land development and resource protection of the Jialing River basin. Based on second generation high-throughput sequencing technology, the diversity, structural composition, functional types, and influencing factors of soil bacterial communities in different land use types were analyzed. The results showed that:① there were some differences in soil physical and chemical properties among different land uses. The nutritional indexes of agricultural land and soil wetland were significantly higher than those of natural forest land and sandy soil wetland (P<0.05). ②The Ace, Shannon, and Chao indexes of sandy soil wetland and soil wetland were significantly higher than those of natural forest land and agricultural land (P<0.05). The Simpson index of soil bacteria in different land use types was significantly different (P<0.05). ③ The dominant phyla of soil bacteria in the coastal zone of the Jialing River were Proteobacteria, Actinobacteriata, Acidobacteriata, and Chloroflexi, and the relative abundance accounted for more than 65%. The community structure of sandy soil wetland was similar to that of soil wetland and was significantly different from that of other land use types (P<0.05). ④ Primary functional metabolism was the core function of the bacterial community, accounting for more than 75%. Agricultural activities had the greatest impact on the community function, which significantly improved the metabolism of amino acids and carbohydrates, enhanced the utilization of nitrogen and phosphorus, reduced the metabolism of energy and coenzyme vitamins, and weakened the resistance of bacterial community to environmental impact (P<0.05). ⑤ Total phosphorus (TP) was the key influencing factor of the soil bacterial community. In conclusion, the construction of the wetland habitat in the Jialing River coastal zone is most conducive to the development of underground ecological diversity and the stability of the soil ecosystem.