Flow-path changes in permafrost soils affect Fe-organic carbon interactions: evidence from silicon isotopes

Silicon isotope fractionation upon amorphous silica precipitation is sensitive to freeze-thaw cycles in arctic soils that are composed of carbon-rich permafrost (i.e. soil layer that remains frozen for at least two consecutive years) covered by an active layer (i.e. soil layer that thaws in summer i...

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Main Authors: Villani, Maëlle, Hirst, Catherine, Thomas, Maxime, du Bois d'Aische, Eléonore, Vanderelst, Sarah, Lundin, Erik, Giesler, Reiner, Mörth, Magnus, Opfergelt, Sophie, 2024 Belgian Polar Community Day
Other Authors: UCL - SST/ELI/ELIE - Environmental Sciences
Format: Conference Object
Language:English
Published: 2024
Subjects:
Online Access:http://hdl.handle.net/2078.1/287448
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record_format openpolar
spelling ftunivlouvain:oai:dial.uclouvain.be:boreal:287448 2024-06-23T07:50:38+00:00 Flow-path changes in permafrost soils affect Fe-organic carbon interactions: evidence from silicon isotopes Villani, Maëlle Hirst, Catherine Thomas, Maxime du Bois d'Aische, Eléonore Vanderelst, Sarah Lundin, Erik Giesler, Reiner Mörth, Magnus Opfergelt, Sophie 2024 Belgian Polar Community Day UCL - SST/ELI/ELIE - Environmental Sciences 2024 http://hdl.handle.net/2078.1/287448 eng eng info:eu-repo/grantAgreement/FNRS/ASPIRANT/FC 49507 boreal:287448 http://hdl.handle.net/2078.1/287448 Permafrost silicon isotopes sweden info:eu-repo/semantics/conferenceObject 2024 ftunivlouvain 2024-05-29T06:18:54Z Silicon isotope fractionation upon amorphous silica precipitation is sensitive to freeze-thaw cycles in arctic soils that are composed of carbon-rich permafrost (i.e. soil layer that remains frozen for at least two consecutive years) covered by an active layer (i.e. soil layer that thaws in summer in freezes in winter). The consequences of permafrost thaw for organic carbon decomposition are mainly studied during the growing season in summer, considering the soil as inert in winter. Here we show that biogeochemical processes involving organic carbon are present in early winter. We couple silicon isotopes with iron and dissolved organic carbon concentration measurements in soil pore water along a natural gradient of permafrost degradation (intact, intermediate, and thawed sites) and on a downstream river in Stordalen (Sweden) collected over two months during late summer and early winter. The data support that: (i) annual freeze-thaw cycles drive soil-water interaction and biogeochemical processes mostly at the intact site; (ii) early winter snowmelt results in soil water infiltration, water table increase and the dissolution of Fe-oxides at the intermediate site; (iii) early winter snow water infiltration increases lateral flow and export of dissolved organic carbon, especially between the thawed site and the downstream river. Combined, we show an extended period of soil-water interaction in early winter that destabilizes iron-organic carbon associations in permafrost soils and increases dissolved organic carbon transport to rivers. Conference Object Arctic permafrost DIAL@UCLouvain (Université catholique de Louvain) Arctic Stordalen ENVELOPE(7.337,7.337,62.510,62.510)
institution Open Polar
collection DIAL@UCLouvain (Université catholique de Louvain)
op_collection_id ftunivlouvain
language English
topic Permafrost
silicon
isotopes
sweden
spellingShingle Permafrost
silicon
isotopes
sweden
Villani, Maëlle
Hirst, Catherine
Thomas, Maxime
du Bois d'Aische, Eléonore
Vanderelst, Sarah
Lundin, Erik
Giesler, Reiner
Mörth, Magnus
Opfergelt, Sophie
2024 Belgian Polar Community Day
Flow-path changes in permafrost soils affect Fe-organic carbon interactions: evidence from silicon isotopes
topic_facet Permafrost
silicon
isotopes
sweden
description Silicon isotope fractionation upon amorphous silica precipitation is sensitive to freeze-thaw cycles in arctic soils that are composed of carbon-rich permafrost (i.e. soil layer that remains frozen for at least two consecutive years) covered by an active layer (i.e. soil layer that thaws in summer in freezes in winter). The consequences of permafrost thaw for organic carbon decomposition are mainly studied during the growing season in summer, considering the soil as inert in winter. Here we show that biogeochemical processes involving organic carbon are present in early winter. We couple silicon isotopes with iron and dissolved organic carbon concentration measurements in soil pore water along a natural gradient of permafrost degradation (intact, intermediate, and thawed sites) and on a downstream river in Stordalen (Sweden) collected over two months during late summer and early winter. The data support that: (i) annual freeze-thaw cycles drive soil-water interaction and biogeochemical processes mostly at the intact site; (ii) early winter snowmelt results in soil water infiltration, water table increase and the dissolution of Fe-oxides at the intermediate site; (iii) early winter snow water infiltration increases lateral flow and export of dissolved organic carbon, especially between the thawed site and the downstream river. Combined, we show an extended period of soil-water interaction in early winter that destabilizes iron-organic carbon associations in permafrost soils and increases dissolved organic carbon transport to rivers.
author2 UCL - SST/ELI/ELIE - Environmental Sciences
format Conference Object
author Villani, Maëlle
Hirst, Catherine
Thomas, Maxime
du Bois d'Aische, Eléonore
Vanderelst, Sarah
Lundin, Erik
Giesler, Reiner
Mörth, Magnus
Opfergelt, Sophie
2024 Belgian Polar Community Day
author_facet Villani, Maëlle
Hirst, Catherine
Thomas, Maxime
du Bois d'Aische, Eléonore
Vanderelst, Sarah
Lundin, Erik
Giesler, Reiner
Mörth, Magnus
Opfergelt, Sophie
2024 Belgian Polar Community Day
author_sort Villani, Maëlle
title Flow-path changes in permafrost soils affect Fe-organic carbon interactions: evidence from silicon isotopes
title_short Flow-path changes in permafrost soils affect Fe-organic carbon interactions: evidence from silicon isotopes
title_full Flow-path changes in permafrost soils affect Fe-organic carbon interactions: evidence from silicon isotopes
title_fullStr Flow-path changes in permafrost soils affect Fe-organic carbon interactions: evidence from silicon isotopes
title_full_unstemmed Flow-path changes in permafrost soils affect Fe-organic carbon interactions: evidence from silicon isotopes
title_sort flow-path changes in permafrost soils affect fe-organic carbon interactions: evidence from silicon isotopes
publishDate 2024
url http://hdl.handle.net/2078.1/287448
long_lat ENVELOPE(7.337,7.337,62.510,62.510)
geographic Arctic
Stordalen
geographic_facet Arctic
Stordalen
genre Arctic
permafrost
genre_facet Arctic
permafrost
op_relation info:eu-repo/grantAgreement/FNRS/ASPIRANT/FC 49507
boreal:287448
http://hdl.handle.net/2078.1/287448
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