Silicon isotopes as a tool to capture winter biogeochemical processes in permafrost soils

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, du Bois d'Aische, Eléonore, Thomas, Maxime, Lundin, Erik, Giesler, Reiner, Mörth, Magnus, Opfergelt, Sophie, Isotopes in Biogenic Silica (IBiS) 2024
Other Authors: UCL - SST/ELI/ELIE - Environmental Sciences
Format: Conference Object
Language:English
Published: 2024
Subjects:
Online Access:http://hdl.handle.net/2078.1/287449
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spelling ftunistlouisbrus:oai:dial.uclouvain.be:boreal:287449 2024-06-23T07:50:36+00:00 Silicon isotopes as a tool to capture winter biogeochemical processes in permafrost soils Villani, Maëlle Hirst, Catherine du Bois d'Aische, Eléonore Thomas, Maxime Lundin, Erik Giesler, Reiner Mörth, Magnus Opfergelt, Sophie Isotopes in Biogenic Silica (IBiS) 2024 UCL - SST/ELI/ELIE - Environmental Sciences 2024 http://hdl.handle.net/2078.1/287449 eng eng info:eu-repo/grantAgreement/FNRS/ASPIRANT/FC 49507 boreal:287449 http://hdl.handle.net/2078.1/287449 Permafrost silicon isotopes info:eu-repo/semantics/conferenceObject 2024 ftunistlouisbrus 2024-05-27T23:50:22Z 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@USL-B (Université Saint-Louis, Bruxelles) Arctic Stordalen ENVELOPE(7.337,7.337,62.510,62.510)
institution Open Polar
collection DIAL@USL-B (Université Saint-Louis, Bruxelles)
op_collection_id ftunistlouisbrus
language English
topic Permafrost
silicon
isotopes
spellingShingle Permafrost
silicon
isotopes
Villani, Maëlle
Hirst, Catherine
du Bois d'Aische, Eléonore
Thomas, Maxime
Lundin, Erik
Giesler, Reiner
Mörth, Magnus
Opfergelt, Sophie
Isotopes in Biogenic Silica (IBiS) 2024
Silicon isotopes as a tool to capture winter biogeochemical processes in permafrost soils
topic_facet Permafrost
silicon
isotopes
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
du Bois d'Aische, Eléonore
Thomas, Maxime
Lundin, Erik
Giesler, Reiner
Mörth, Magnus
Opfergelt, Sophie
Isotopes in Biogenic Silica (IBiS) 2024
author_facet Villani, Maëlle
Hirst, Catherine
du Bois d'Aische, Eléonore
Thomas, Maxime
Lundin, Erik
Giesler, Reiner
Mörth, Magnus
Opfergelt, Sophie
Isotopes in Biogenic Silica (IBiS) 2024
author_sort Villani, Maëlle
title Silicon isotopes as a tool to capture winter biogeochemical processes in permafrost soils
title_short Silicon isotopes as a tool to capture winter biogeochemical processes in permafrost soils
title_full Silicon isotopes as a tool to capture winter biogeochemical processes in permafrost soils
title_fullStr Silicon isotopes as a tool to capture winter biogeochemical processes in permafrost soils
title_full_unstemmed Silicon isotopes as a tool to capture winter biogeochemical processes in permafrost soils
title_sort silicon isotopes as a tool to capture winter biogeochemical processes in permafrost soils
publishDate 2024
url http://hdl.handle.net/2078.1/287449
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:287449
http://hdl.handle.net/2078.1/287449
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