Climate warming has direct and indirect effects on microbes associated with carbon cycling in northern lakes ...

• Main Authors: Winder, Johanna, Braga, Lucas, Kuhn, McKenzie, Thompson, Lauren, Olefeldt, David, Tanentzap, Andrew
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2023
• Subjects: aquatic carbon cycling; community composition; functional gene analysis; groundwater connectivity; metagenomics; methanogenesis; methanotrophy; permafrost thaw; Canada; permafrost
• Online Access: https://dx.doi.org/10.17863/cam.94410; https://www.repository.cam.ac.uk/handle/1810/346988

Northern lakes disproportionately influence the global carbon cycle, and may do so more in the future depending on how their microbial communities respond to climate warming. Microbial communities can change because of the direct effects of climate warming on their metabolism and the indirect effects of climate warming on groundwater connectivity from thawing of surrounding permafrost, especially at lower landscape positions. Here we used shotgun metagenomics to compare the taxonomic and functional gene composition of sediment microbes in 19 peatland lakes across a 1600-km permafrost transect in boreal western Canada. We found microbes responded differently to the loss of regional permafrost cover than to increases in local groundwater connectivity. These results suggest that both the direct and indirect effects of climate warming, which were respectively associated with loss of permafrost thaw and subsequent changes in groundwater connectivity interact to change microbial composition and function. Archaeal ...