Spatial and Temporal Variation in Microbial Diversity and Community Structure in a Contaminated Mangrove Wetland

Abstract

Field and laboratory investigations were conducted to characterize bacterial diversity and community structure in a badly contaminated mangrove wetland adjacent to the metropolitan area of a megacity in subtropical China. Next-generation sequencing technique was used for sequencing the V4-V5 region of the 16s rRNA gene on the Illumina system. Collectively, Proteobacteria, Chloroflexi, Planctomycetes, Actinobacteria and Bacteroidetes were the predominant phyla identified in the investigated soils. A significant spatial variation in bacterial diversity and community structure was observed for the investigated mangrove soils. Heavy metal pollution played a key role in reducing the bacterial diversity. The spatial variation in soil-borne heavy metals shaped the spatial variation in bacterial diversity and community structure in the study area. Other environmental factors such as total carbon and total nitrogen in the soils that are affected by seasonal change in temperature could also influence the bacterial abundance, diversity and community structure though the temporal variation was relatively weaker, as compared to spatial variation. The bacterial diversity index was lower in the investigated site than in the comparable reference site with less contaminated status. The community structure in mangrove soils at the current study site was, to a remarkable extent, different from those in the tropical mangrove wetlands around the world.

Microbial Community Changes across Time and Space in a Constructed Wetland

“…This discrepancy may be due to the Chao1 index's greater sensitivity to rare species, which could lead to an underestimation of diversity in the WC1 inflow sample. Ma et al, 2020, 40 showed that, in soil samples, the warmer months significantly increased the α diversity indices compared to the cooler months, possibly due to environmental variables such as pH, temperature, and trace metal content. Likewise, it was found that pollution and pH negatively affected the diversity of microbial communities in acid mine drainage contaminated natural wetlands.…”

The Right Place at the Right Time: Seasonal Variation of Bacterial Communities in Arid Avicennia marina Soils in the Red Sea Is Specific to Its Position in the Intertidal

“…diversity indices in summer likely due to cooler winter temperatures inhibiting microbial activity (Ma et al, 2020). In the Red Sea tidal amplitudes are small because of the constricted connection to the Gulf of Aden and the Indian Ocean (Pugh et al, 2019).…”

“…Despite their role in the delivery of this ecosystem service microbial communities in mangrove soils have received little attention in comparison to other marine and terrestrial environments (Thompson et al, 2017;Bahram et al, 2018). Notably, there is still limited research into spatial and temporal variation patterns of bacterial community assemblages in mangrove soils (Ma et al, 2020;Zhang et al, 2021). A few studies have assessed the role of biotic and abiotic factors to better understand the ecological drivers that influence spatial patterns of microbial communities in mangrove soils (Alongi, 2005;Reef et al, 2010;Thomson et al, 2022).…”