Labile carbon limits late winter microbial activity near Arctic treeline

Abstract Soil microbial communities remain active during much of the Arctic winter, despite deeply frozen soils. Overwinter microbial activity affects the global carbon (C) budget, nutrient cycling, and vegetation composition. Microbial respiration is highly temperature sensitive in frozen soils, as...

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Bibliographic Details
Published in:Nature Communications
Main Authors: Sullivan, Patrick F., Stokes, Madeline C., McMillan, Cameron K., Weintraub, Michael N.
Format: Article in Journal/Newspaper
Language:English
Published: Springer Science and Business Media LLC 2020
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Online Access:http://dx.doi.org/10.1038/s41467-020-17790-5
https://www.nature.com/articles/s41467-020-17790-5.pdf
https://www.nature.com/articles/s41467-020-17790-5
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Summary:Abstract Soil microbial communities remain active during much of the Arctic winter, despite deeply frozen soils. Overwinter microbial activity affects the global carbon (C) budget, nutrient cycling, and vegetation composition. Microbial respiration is highly temperature sensitive in frozen soils, as liquid water and solute availability decrease rapidly with declining temperature. Climate warming and changes in snowpack are leading to warmer Arctic winter soils. Warmer winter soils are thought to yield greater microbial respiration of available C, greater overwinter CO 2 efflux and greater nutrient availability to plants at thaw. Using field and laboratory observations and experiments, we demonstrate that persistently warm winter soils can lead to labile C starvation and reduced microbial respiration, despite the high C content of most Arctic soils. If winter soils continue to warm, microbial C limitation will reduce expected CO 2 emissions and alter soil nutrient cycling, if not countered by greater labile C inputs.