Geochemical drivers of organic matter decomposition in arctic tundra soils
International audience Climate change is warming tundra ecosystems in the Arctic, resulting in the decomposition of previously-frozen soil organic matter (SOM) and release of carbon (C) to the atmosphere; however, the processes that control SOM decomposition and C emissions remain highly uncertain....
Published in: | Biogeochemistry |
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ftinsu:oai:HAL:hal-01254228v1 2023-12-03T10:17:32+01:00 Geochemical drivers of organic matter decomposition in arctic tundra soils Herndon, Elizabeth M. Yang, Ziming Bargar, John Janot, Noemie Regier, Tom Z. Graham, David E. Wullschleger, Stan D. Gu, Baohua Liang, Liyuan Environmental Sciences Division Oak Ridge Oak Ridge National Laboratory Oak Ridge (ORNL) UT-Battelle, LLC-UT-Battelle, LLC SLAC National Accelerator Laboratory (SLAC) Stanford University Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC) Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS) Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo) Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS) Canadian Light Source University of Saskatchewan Saskatoon (U of S) BioSciences Division Oak Ridge 2015-12 https://hal.science/hal-01254228 https://doi.org/10.1007/s10533-015-0165-5 en eng HAL CCSD Springer Verlag info:eu-repo/semantics/altIdentifier/doi/10.1007/s10533-015-0165-5 hal-01254228 https://hal.science/hal-01254228 doi:10.1007/s10533-015-0165-5 ISSN: 0168-2563 EISSN: 1573-515X Biogeochemistry https://hal.science/hal-01254228 Biogeochemistry, 2015, 126 (3), pp.397-414. ⟨10.1007/s10533-015-0165-5⟩ Iron biogeochemistry Tundra soil Active layer Soil organic matter Methane [SDE]Environmental Sciences [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry info:eu-repo/semantics/article Journal articles 2015 ftinsu https://doi.org/10.1007/s10533-015-0165-5 2023-11-08T17:32:49Z International audience Climate change is warming tundra ecosystems in the Arctic, resulting in the decomposition of previously-frozen soil organic matter (SOM) and release of carbon (C) to the atmosphere; however, the processes that control SOM decomposition and C emissions remain highly uncertain. In this study, we evaluate geochemical factors that influence microbial production of carbon dioxide (CO2) and methane (CH4) in the seasonally-thawed active layer of interstitial polygonal tundra near Barrow, Alaska. We report spatial and seasonal patterns of dissolved gases in relation to the geochemical properties of Fe and organic C in soil and soil solution, as determined using spectroscopic and chromatographic techniques. The chemical composition of soil water collected during the annual thaw season varied significantly with depth. Soil water in the middle of the active layer contained abundant Fe(III), and aromatic-C and low-molecular-weight organic acids derived from SOM decomposition. At these depths, CH4 was positively correlated with the ratio of Fe(III) to total Fe in waterlogged transitional and low-centered polygons but negatively correlated in the drier flat- and high-centered polygons. These observations contradict the expectation that CH4 would be uniformly low where Fe(III) was high due to inhibition of methanogenesis by Fe(III)-reduction reactions. Our results suggest that vertically-stratified Fe redox reactions influence respiration/fermentation of SOM and production of substrates (e.g., low-molecular-weight organic acids) for methanogenesis, but that these effects vary with soil moisture. We infer that geochemical differences induced by water saturation dictate microbial products of SOM decomposition, and Fe geochemistry is an important factor regulating methanogenesis in anoxic tundra soils. Article in Journal/Newspaper Arctic Barrow Climate change Tundra Alaska Institut national des sciences de l'Univers: HAL-INSU Arctic Biogeochemistry 126 3 397 414 |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
Iron biogeochemistry Tundra soil Active layer Soil organic matter Methane [SDE]Environmental Sciences [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry |
spellingShingle |
Iron biogeochemistry Tundra soil Active layer Soil organic matter Methane [SDE]Environmental Sciences [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry Herndon, Elizabeth M. Yang, Ziming Bargar, John Janot, Noemie Regier, Tom Z. Graham, David E. Wullschleger, Stan D. Gu, Baohua Liang, Liyuan Geochemical drivers of organic matter decomposition in arctic tundra soils |
topic_facet |
Iron biogeochemistry Tundra soil Active layer Soil organic matter Methane [SDE]Environmental Sciences [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry |
description |
International audience Climate change is warming tundra ecosystems in the Arctic, resulting in the decomposition of previously-frozen soil organic matter (SOM) and release of carbon (C) to the atmosphere; however, the processes that control SOM decomposition and C emissions remain highly uncertain. In this study, we evaluate geochemical factors that influence microbial production of carbon dioxide (CO2) and methane (CH4) in the seasonally-thawed active layer of interstitial polygonal tundra near Barrow, Alaska. We report spatial and seasonal patterns of dissolved gases in relation to the geochemical properties of Fe and organic C in soil and soil solution, as determined using spectroscopic and chromatographic techniques. The chemical composition of soil water collected during the annual thaw season varied significantly with depth. Soil water in the middle of the active layer contained abundant Fe(III), and aromatic-C and low-molecular-weight organic acids derived from SOM decomposition. At these depths, CH4 was positively correlated with the ratio of Fe(III) to total Fe in waterlogged transitional and low-centered polygons but negatively correlated in the drier flat- and high-centered polygons. These observations contradict the expectation that CH4 would be uniformly low where Fe(III) was high due to inhibition of methanogenesis by Fe(III)-reduction reactions. Our results suggest that vertically-stratified Fe redox reactions influence respiration/fermentation of SOM and production of substrates (e.g., low-molecular-weight organic acids) for methanogenesis, but that these effects vary with soil moisture. We infer that geochemical differences induced by water saturation dictate microbial products of SOM decomposition, and Fe geochemistry is an important factor regulating methanogenesis in anoxic tundra soils. |
author2 |
Environmental Sciences Division Oak Ridge Oak Ridge National Laboratory Oak Ridge (ORNL) UT-Battelle, LLC-UT-Battelle, LLC SLAC National Accelerator Laboratory (SLAC) Stanford University Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC) Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS) Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo) Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS) Canadian Light Source University of Saskatchewan Saskatoon (U of S) BioSciences Division Oak Ridge |
format |
Article in Journal/Newspaper |
author |
Herndon, Elizabeth M. Yang, Ziming Bargar, John Janot, Noemie Regier, Tom Z. Graham, David E. Wullschleger, Stan D. Gu, Baohua Liang, Liyuan |
author_facet |
Herndon, Elizabeth M. Yang, Ziming Bargar, John Janot, Noemie Regier, Tom Z. Graham, David E. Wullschleger, Stan D. Gu, Baohua Liang, Liyuan |
author_sort |
Herndon, Elizabeth M. |
title |
Geochemical drivers of organic matter decomposition in arctic tundra soils |
title_short |
Geochemical drivers of organic matter decomposition in arctic tundra soils |
title_full |
Geochemical drivers of organic matter decomposition in arctic tundra soils |
title_fullStr |
Geochemical drivers of organic matter decomposition in arctic tundra soils |
title_full_unstemmed |
Geochemical drivers of organic matter decomposition in arctic tundra soils |
title_sort |
geochemical drivers of organic matter decomposition in arctic tundra soils |
publisher |
HAL CCSD |
publishDate |
2015 |
url |
https://hal.science/hal-01254228 https://doi.org/10.1007/s10533-015-0165-5 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Barrow Climate change Tundra Alaska |
genre_facet |
Arctic Barrow Climate change Tundra Alaska |
op_source |
ISSN: 0168-2563 EISSN: 1573-515X Biogeochemistry https://hal.science/hal-01254228 Biogeochemistry, 2015, 126 (3), pp.397-414. ⟨10.1007/s10533-015-0165-5⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1007/s10533-015-0165-5 hal-01254228 https://hal.science/hal-01254228 doi:10.1007/s10533-015-0165-5 |
op_doi |
https://doi.org/10.1007/s10533-015-0165-5 |
container_title |
Biogeochemistry |
container_volume |
126 |
container_issue |
3 |
container_start_page |
397 |
op_container_end_page |
414 |
_version_ |
1784264484368416768 |