Effects of Atmospheric Particulate Matter on Microbial Communities in Wetland Ecosystems

As an important component of urban ecosystems, changes in microbial communities in urban wetland ecosystems have a profound impact on human beings. In this paper, we studied the changes in microbial communities in urban wetland ecosystems (three major interfaces: atmosphere, foliage and water) under the background of atmospheric pollution by high-throughput techniques. The α-diversity of microorganisms at each interface showed that the species richness of the sample communities did not differ significantly at different levels of contamination and it was all at a high level. And the β-diversity showed a significantly larger between-group gap than within-group gap between the samples. The functions predicted a higher metabolic function in water samples and atmospheric samples, and a higher function of microorganisms harmful to humans in the microbial community on the leaf surface. Further analysis of the correlation between atmospheric particulate matter and environmental microorganisms revealed that the atmospheric microbial communities that were strongly negatively correlated with TSP, PM10, PM2.5, and PM1 were Actinobacteriota, Cyanobacteria, and Verrucomicrobiota. Among the microbial communities on the leaf surface, only Bacteroidota was strongly positively correlated with total suspended particle (TSP), particles with a diameter of 10 micrometers or less (PM10), particles with a diameter of 2.5 micrometers or less (PM2.5) and particles with a diameter of 1 micrometers or less (PM1). As for the microbial communities in the water column, Firmicutes, Bacteroidota, Campilobacterota, and Deferribacteres were strongly and positively correlated with the different particle sizes. There was no significant correlation between the functions of the three interfacial microorganisms and the particle size of the atmospheric particles. This paper studies the structure and function of microbial communities within three interfaces at three pollution levels and explores the resulting changes with the aim of providing directions for monitoring urban wetland ecosystems and for species diversity conservation.