NITROKARST | Effects of permafrost thaw on the global nitrogen cycle: the role of thermokarst systems

Summary
Global change leads modifications in climate on Arctic regions, where temperatures have risen faster than in any other region on Earth. Those regions store vast amounts of soil organic matter (SOM) in permafrost soils, covering ~25% of terrestrial surface. When they thaw, it leads to rapid release of nutrients and greenhouse gases (GHG). So far, many studies have addressed the importance of permafrost thaw in the carbon cycle. However, little attention has been paid to the nitrogen (N) cycle, despite nitrous oxide (N2O) is a powerful GHG, an ozone-depleting agent and may create an unaccounted permafrost-climate feedback.

Permafrost with low ice content suffers a gradual top-down thawing process during seasonal freeze-thaw period. However, thaw of ice-rich permafrost results in thermokarst processes, which occur abruptly and lead to ground surface collapse. Its widespread occurrence affects large areas (~40% of the northern permafrost region) contributing to develop ecosystems like ponds and lakes. In such ecosystems, the presence of anaerobic environments enhances microbial activity. As Arctic warms, permafrost thaw and thermokarst processes will increase, releasing soluble N into the environment and enhancing microbial decomposition of SOM.

Hence, mineralization, nitrification and denitrification rates are expected to increase, and thus, N2O emissions to the atmosphere. Unfortunately, the impact of permafrost thaw on N cycling remains understudied, and almost unknown in thermokarst systems.
NITROKARST will explore the underlying mechanisms of the N cycle in thermokarst systems, looking at how microbial pathways promote N transformation and how thawing controls the operation of these processes. N cycling will be studied along a thermokarst transect by combining isotope tracing, metagenomics and microcosm incubations. This multidisciplinary approach will increase our knowledge about the importance of thermokarst-affected permafrost soils in the global N cycle.
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More information & hyperlinks
Web resources: https://cordis.europa.eu/project/id/101024321
Start date: 01-02-2022
End date: 31-01-2024
Total budget - Public funding: 174 167,04 Euro - 174 167,00 Euro
Cordis data

Original description

Global change leads modifications in climate on Arctic regions, where temperatures have risen faster than in any other region on Earth. Those regions store vast amounts of soil organic matter (SOM) in permafrost soils, covering ~25% of terrestrial surface. When they thaw, it leads to rapid release of nutrients and greenhouse gases (GHG). So far, many studies have addressed the importance of permafrost thaw in the carbon cycle. However, little attention has been paid to the nitrogen (N) cycle, despite nitrous oxide (N2O) is a powerful GHG, an ozone-depleting agent and may create an unaccounted permafrost-climate feedback.

Permafrost with low ice content suffers a gradual top-down thawing process during seasonal freeze-thaw period. However, thaw of ice-rich permafrost results in thermokarst processes, which occur abruptly and lead to ground surface collapse. Its widespread occurrence affects large areas (~40% of the northern permafrost region) contributing to develop ecosystems like ponds and lakes. In such ecosystems, the presence of anaerobic environments enhances microbial activity. As Arctic warms, permafrost thaw and thermokarst processes will increase, releasing soluble N into the environment and enhancing microbial decomposition of SOM.

Hence, mineralization, nitrification and denitrification rates are expected to increase, and thus, N2O emissions to the atmosphere. Unfortunately, the impact of permafrost thaw on N cycling remains understudied, and almost unknown in thermokarst systems.
NITROKARST will explore the underlying mechanisms of the N cycle in thermokarst systems, looking at how microbial pathways promote N transformation and how thawing controls the operation of these processes. N cycling will be studied along a thermokarst transect by combining isotope tracing, metagenomics and microcosm incubations. This multidisciplinary approach will increase our knowledge about the importance of thermokarst-affected permafrost soils in the global N cycle.

Status

TERMINATED

Call topic

MSCA-IF-2020

Update Date

28-04-2024
Geographical location(s)
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EU-Programme-Call
Horizon 2020
H2020-EU.1. EXCELLENT SCIENCE
H2020-EU.1.3. EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions (MSCA)
H2020-EU.1.3.2. Nurturing excellence by means of cross-border and cross-sector mobility
H2020-MSCA-IF-2020
MSCA-IF-2020 Individual Fellowships