Terrestrial connectivity, upstream aquatic history and seasonality shape bacterial community assembly within a large boreal aquatic network 🦠🏞️
Authored by: Masumi Stadler and Paul A. del Giorgio
Affiliation: Groupe de Recherche Interuniversitaire en Limnologie (GRIL), Département des Sciences Biologiques, Université du Québec à Montréal, Montréal, QC, Canada
This work has been published
Raw sequences are available on the public NCBI Sequence Read Archive (SRA) as part of the BioProject PRJNA69302. The intermediate data files are too big to be stored on Github and are hence published separetely on Zenodo (see separate repository locations below).
- Publication: Stadler M, del Giorgio PA. Terrestrial connectivity, upstream aquatic history and seasonality shape bacterial community assembly within a large boreal aquatic network. ISME J 2022; 16: 937–947.
- Code: Masumi Stadler. (2021). CarBBAS/Paper_Stadler-delGiorgio_ISMEJ_2021: v1.0-beta. In The ISME Journal (beta). Zenodo. https://doi.org/10.5281/zenodo.5567270
- Processed microbial data: Stadler, Masumi, Ruiz-González, Clara, Vick-Majors, Trista J, & del Giorgio, Paul A. (2021). Microbial 16S rRNA gene (DNA) and transcripts (cDNA) along a boreal soil-freshwater-estuary continuum (v1.0) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.4611420
During transit from soils to the ocean, microbial communities are modified and re-assembled, generating complex patterns of ecological succession. The potential effect of upstream assembly on downstream microbial community composition is seldom considered within aquatic networks. Here, we reconstructed the microbial succession along a land-freshwater-estuary continuum within La Romaine river watershed in Northeastern Canada. We captured hydrological seasonality and differentiated the total and reactive community by sequencing both 16S rRNA genes and transcripts. By examining how DNA- and RNA-based assemblages diverge and converge along the continuum, we inferred temporal shifts in the relative importance of assembly processes, with mass effects dominant in spring, and species selection becoming stronger in summer. The location of strongest selection within the network differed between seasons, suggesting that selection hotspots shift depending on hydrological conditions. The unreactive fraction (no/minor RNA contribution) was composed of taxa with diverse potential origins along the whole aquatic network, while the majority of the reactive pool (major RNA contribution) could be traced to soil/soilwater taxa, which were distributed along the entire rank-abundance curve. Overall, our findings highlight the importance of considering upstream history, hydrological seasonality and the reactive microbial fraction to fully understand microbial community assembly on a network scale.
This study is part of the program of the Carbon Biogeochemistry in Boreal Aquatic Systems (CarBBAS) Industrial Research Chair, co-funded by the Natural Science and Engineering Research Council of Canada (NSERC) and Hydro-Québec.
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
