Soil microbial succession with soil development since costal reclamation

Abstract

Large area of tidal flats in Chinese coast has been reclaimed to support agriculture and urban development because of rapid population and economic growth. Knowledge of soil development mechanisms is essential for efficient management of land resources in coastal zone. So far, most studies have focused on consequences of soil physico-chemical properties on soil quality evolution after tideland reclamation for cultivation. However, a large part of soil bioprocess drives many soil processes and the effect of organism composition on the performance of soil development remains unclear. In this study, temporal dynamics of microbial communities were investigated by DNA metabarcoding to delineate the patterns and drivers of soil microbial succession along a chronosequence since reclamation from tidal flat in the Yangtze River Delta of China. Soil physicochemical properties and soil microbial structure shifted significantly, indicating the development of soil fertility. Both soil bacterial and eukaryotic diversities significantly increased after about 60 years of agricultural reclamation. Succession of bacterial structure was linked with significant decrease in the relative abundance of Proteobacteria and increase in the relative abundance of Acidobacteria. Succession of eukaryote structure exhibited significant decrease in the relative abundance of Metazoa and Ochrophyta and increase in the relative abundance of Fungi. Further analysis indicated that temporal and environmental filters act together to structure soil microbial communities across long-term cultivation. An orderly growth of soil microbial community and diversity with respect to soil fertility development has been verified. The succession of soil microbial community and diversity towards higher soil quality after the tidal flat reclamation, which was mainly correlated with soil physicochemical changes with time.