Damming river shapes distinct patterns and processes of planktonic bacterial and microeukaryotic communities

Abstract

Planktonic bacterial and microeukaryotic communities play important roles in biogeochemical cycles, but their biogeographic patterns and community assembly processes in large damming rivers still remain unclear. In this study, 16S rRNA and 18S rRNA coding genes were used for sample sequencing analysis of planktonic bacterial and microeukaryotic communities in the upper Yangtze River. The upper Yangtze River was divided into damaffected zones and river zones based on the influence of dams. The results showed that there were significant differences in the bacterial and microeukaryotic communities between the two zones and that dams significantly reduced the α-diversity of the bacterial communities. Co-occurrence network analysis indicated that networks in the river zone were denser than those in the dam-affected zone. The relationships among species in bacterial networks were more complex than those in microeukaryotic networks. Dispersal limitation and ecological drift were the main processes influencing planktonic bacterial and microeukaryotic communities in the dam-affected zone respectively, whereas the role of deterministic processes increased in the river zone. Anthropogenic activities and hydraulic conditions affected suspended sediment and controlled microbial diversity in the river zone. These results suggest that dams impact planktonic bacteria more strongly than planktonic microeukaryotes, indicating that the distribution patterns and processes of the bacterial and microeukaryotic communities in large rivers are significantly different.

Planktonic archaea reveal stronger dispersal limitation and more network connectivity than planktonic bacteria in the Jinsha River of southwestern China

“…Dams, especially cascade hydropower dams, are serious anthropogenic disturbances in rivers that may affect the biogeographical patterns of the planktonic microbial communities (Grantham et al, 2014; Han et al, 2018). A previous study suggested that operation of dams had a considerable impact on the biogeographical patterns of bacteria and microeukaryote in the upper Yangtze River (Lu et al, 2022). This is likely to be because cascade hydropower dams impact connectivity among river regions, resulting in spatial segregation of microbial communities in different reservoir areas (Chen et al, 2021).…”

Multidecadal assessment of environmental variables in the river Ganga for pollution monitoring and sustainable management

“…The impact of various anthropogenic factors on natural habitats is well documented. With the amplified impact of anthropogenic activities, various naturally occurring ecological niches have been destroyed (Lu et al, 2022). The deterioration of water quality and its impact on deterioration in the river Ganga ecology is noteworthy (Das et al, 2022).…”

Metabarcoding reveals the differential sensitivity of planktonic microbiome to environmental filtering and biointeraction in Sansha Yongle blue hole

“…The difference of assembly mechanism between prokaryotic and microeukaryotic community in SYBH is consistent with previous research on protist and bacteria in global surface waters (Logares et al, 2020) and upwelling system (Sun et al, 2022), but contradict with that in East China Sea's euphotic zone where protist community is mainly structured by selection processes (Wu et al, 2018). Such inconsistency has been discussed in several studies on microbiomes across different ecosystems (Xue et al, 2018;Xiong et al, 2021;Lu et al, 2022;Sun et al, 2022), supporting that the combined effect of species, straits, habitat type, spatiotemporal scale and environmental gradient determine the relative contribution of determinism and stochasticity in shaping the microbial landscape (Chase and Myers, 2011;Hanson et al, 2012;Morrison-Whittle and Goddard, 2015).…”

“…Although amplicon libraries for metabarcoding of prokaryotes and eukaryotes have to be prepared separately due to the distinct nucleotide characters, they form microbial assemblage in natural waters and play roles together in ecological processes such a microbial food web. Recently, increasing attention has been paid to joint analysis of microbial prokaryotic and eukaryotic plankton in aquatic ecosystems (Jiang et al, 2018;Wu et al, 2020;Lu et al, 2022;Sun et al, 2022), revealing that the distribution patterns and assembly mechanisms are distinct between domains, and cross-domain interaction plays an important role in shaping the plankton community, even overriding abiotic factor in some cases. Which process contributes more to the community assembly?…”