Effects of Plants on Metacommunities and Correlation Networks of Soil Microbial Groups in an Ecologically Restored Wetland.

Abstract

Plants may influence different aspects of the belowground microorganisms, including abundance, distribution, and interaction, in wetlands. Microbial communities were scrutinized in a 4-year-old restored wetland ecosystem with 5 distinct sites: a bare-soil site (10 local patches) and sites dominated by Miscanthus, Phragmites, Typha, and Zizania (20 patches per site). Ordination analysis revealed that plant-induced attributes (e.g., organic matter and total carbon and nitrogen) could explain the total environmental variance. Community comparisons showed that all groups (Bacteria, Fungi, Protista, and Metazoa) differed in community structure among the 5 sites (P < 0.05). Comparisons between the community and environmental ordination plots revealed that community structural variation among the sites correlated with the environmental change across all groups (R2 ≥ 0.61). This indicates that all groups were primarily influenced by plant detritus. In addition, correlation networks markedly varied in topology and composition among the sites across all groups. There was a strong coupling between the metacommunity and correlation network for both Bacteria and Fungi (R2 ≥ 0.58), indicating that the plants determined the spatial covariation patterns of microbial populations. Multi-group networks and group synchrony results revealed that Bacteria, Fungi, and Protista were synchronized with each other (R2 ≥ 0.52) as the key founders of the microbial systems, while Metazoa participated in the system only under Miscanthus. Our findings concluded that the plants shaped the communities by controlling the abundance and interaction of their populations.