Active layer microbial inocula restore missing functions across thawed permafrost soils
Abstract
Microbial dynamics in thawing permafrost induce a climate feedback of uncertain magnitude. Upon thaw, active layer microorganisms may establish in formerly frozen layers and introduce missing functions. Here we test the prevalence of functional limitations and how active layer microorganisms can mitigate these across four widespread permafrost types over 389 days. By restoring functions with a multifunctional microbial community, we demonstrate widespread functional limitations, as increased CO 2 emissions across four permafrost types, and onset N 2 O emissions in two of those. However, realistic active layer inocula increased CO 2 or N 2 O production less than the multifunctional community, due to unsuccessful coalescence or limitations in the inocula. Under anoxia, active layer inocula quintupled CH 4 while decreasing CO 2 production, resulting in a 35% increase in CO 2 -eq over six months. Understanding the functional limitations of permafrost microbial communities will be key to predicting their substantial, yet unaccounted, consequences on the biogeochemistry of the permafrost region.
Arctic permafrost soils store large amounts of carbon (C) that can fuel greenhouse gas (GHG) emissions when these soils thaw due to climate change 1,2 . Understanding the feedback between global warming and GHG emissions from these soils is important for climate change mitigation strategies 2-4 . Research efforts have been dedicated to sampling both the perennially frozen permafrost and the seasonally thawing active layer of soil profiles across the Arctic, to relate soil physical and chemical composition to long-term GHG production through in vitro incubation studies 1,2,5,6 . Incubations provide valuable data and insights into remote sites not easily captured by ecosystem-level measurements, which have allowed model estimates of the permafrost carbonclimate feedback 2,7,8 . However, most incubation studies neglect the role of biotic interactions, notably microbial community assembly and its effects on soil functioning, which appear increasingly important in determining post-thaw permafrost functioning in nature 9-12 . Upon permafrost thaw, microbial community composition often changes substantially 12-14 . This can occur through endogenous changes in the microbial community present in the permafrost under the new
Related
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- Thermal-state transition pathways and spatial differentiation of permafrost in Northeast China
- Abrupt stream acidification and metal mobilization from permafrost degradation
BibTeX
@article{monteux2026active,
title = {{Active layer microbial inocula restore missing functions across thawed permafrost soils}},
author = {Sylvain Monteux and Ellen Dorrepaal and Sébastien Fontaine and Konstantin Gavazov and Sara Hallin and Jaanis Juhanson and Frida Keuper and Alexander T Tveit and Josefine Walz and Rica Wegner and Birgit Wild and Eveline J Krab},
journal = {Nature Communications},
year = {2026},
month = sep,
doi = {10.1038/s41467-026-78060-4},
url = {https://hal.inrae.fr/hal-05840986v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Active layer microbial inocula restore missing functions across thawed permafrost soils
AU - Sylvain Monteux
AU - Ellen Dorrepaal
AU - Sébastien Fontaine
AU - Konstantin Gavazov
AU - Sara Hallin
AU - Jaanis Juhanson
AU - Frida Keuper
AU - Alexander T Tveit
AU - Josefine Walz
AU - Rica Wegner
AU - Birgit Wild
AU - Eveline J Krab
PY - 2026
DA - 2026/09/25
JO - Nature Communications
DO - 10.1038/s41467-026-78060-4
UR - https://hal.inrae.fr/hal-05840986v1
AB - Microbial dynamics in thawing permafrost induce a climate feedback of uncertain magnitude. Upon thaw, active layer microorganisms may establish in formerly frozen layers and introduce missing functions. Here we test the prevalence of functional limitations and how active layer microorganisms can mitigate these across four widespread permafrost types over 389 days. By restoring functions with a multifunctional microbial community, we demonstrate widespread functional limitations, as increased CO 2 emissions across four permafrost types, and onset N 2 O emissions in two of those. However, realistic active layer inocula increased CO 2 or N 2 O production less than the multifunctional community, due to unsuccessful coalescence or limitations in the inocula. Under anoxia, active layer inocula quintupled CH 4 while decreasing CO 2 production, resulting in a 35% increase in CO 2 -eq over six months. Understanding the functional limitations of permafrost microbial communities will be key to predicting their substantial, yet unaccounted, consequences on the biogeochemistry of the permafrost region. Arctic permafrost soils store large amounts of carbon (C) that can fuel greenhouse gas (GHG) emissions when these soils thaw due to climate change 1,2 . Understanding the feedback between global warming and GHG emissions from these soils is important for climate change mitigation strategies 2-4 . Research efforts have been dedicated to sampling both the perennially frozen permafrost and the seasonally thawing active layer of soil profiles across the Arctic, to relate soil physical and chemical composition to long-term GHG production through in vitro incubation studies 1,2,5,6 . Incubations provide valuable data and insights into remote sites not easily captured by ecosystem-level measurements, which have allowed model estimates of the permafrost carbonclimate feedback 2,7,8 . However, most incubation studies neglect the role of biotic interactions, notably microbial community assembly and its effects on soil functioning, which appear increasingly important in determining post-thaw permafrost functioning in nature 9-12 . Upon permafrost thaw, microbial community composition often changes substantially 12-14 . This can occur through endogenous changes in the microbial community present in the permafrost under the new
SN - 2041-1723
SN - 2041-1723
ER -