Microbial carbon use and associated changes in microbial community structure in high-Arctic tundra soils under elevated temperature

https://doi.org/10.1016/j.soilbio.2021.108419Get rights and content
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Highlights

  • OM input of distinct chemical structures drives microbial diversity and function of Arctic soils.

  • Positive priming of SOM was greater with the addition of glycine, under elevated temperature.

  • Most of the responsive taxa utilized cellulose.

  • Responsive prokaryotic and fungal taxa were mainly fast growers with a putatively copiotrophic lifestyle.

  • Upslope and downslope soils had distinct communities, but moisture did not affect CO2 fluxes.

Abstract

In the high-Arctic, increased temperature results in permafrost thawing and increased primary production. This fresh plant-derived material is predicted to prime microbial consortia for degradation of the organic matter stored in tundra soils. However, the effects of warming and plant input on the microbial community structure is hardly known. We assessed the use of glycine, a readily available C and N source, and cellulose, a long C-biopolymer, by prokaryotic and fungal communities using DNA-SIP in tundra soils incubated at 8 °C or 16 °C. Glycine addition contributed mainly to instantaneous microbial carbon use and priming of soil organic matter decomposition, particularly under elevated temperature. By contrast, cellulose was linked to the dominant and active microbial communities, with potential carbon stabilization in soils. Our findings stress the importance of the type of plant-derived material in relation to microbial metabolism in high-Arctic soils and their consequences for the carbon cycle in response to global warming.

Keywords

Greenhouse gas
CO2
High-arctic
Soil
Prokaryotes
Fungi
Temperature
Carbon
Priming
DNA-SIP

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