From fibrous plant residues to mineral-associated organic carbon – the fate of organic matter in Arctic permafrost soils
Permafrost-affected soils of the Arctic account for 70 % or 727 Pg of the soil organic carbon (C) stored in the northern circumpolar permafrost region and therefore play a major role in the global C cycle. Most studies on the budgeting of C storage and the quality of soil organic matter (OM; SOM) in...
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ftdoajarticles:oai:doaj.org/article:3c6c0e75b86a4e60a01636cb3b604b2a 2023-05-15T14:54:28+02:00 From fibrous plant residues to mineral-associated organic carbon – the fate of organic matter in Arctic permafrost soils I. Prater S. Zubrzycki F. Buegger L. C. Zoor-Füllgraff G. Angst M. Dannenmann C. W. Mueller 2020-07-01T00:00:00Z https://doi.org/10.5194/bg-17-3367-2020 https://doaj.org/article/3c6c0e75b86a4e60a01636cb3b604b2a EN eng Copernicus Publications https://www.biogeosciences.net/17/3367/2020/bg-17-3367-2020.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-17-3367-2020 1726-4170 1726-4189 https://doaj.org/article/3c6c0e75b86a4e60a01636cb3b604b2a Biogeosciences, Vol 17, Pp 3367-3383 (2020) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2020 ftdoajarticles https://doi.org/10.5194/bg-17-3367-2020 2022-12-31T14:20:51Z Permafrost-affected soils of the Arctic account for 70 % or 727 Pg of the soil organic carbon (C) stored in the northern circumpolar permafrost region and therefore play a major role in the global C cycle. Most studies on the budgeting of C storage and the quality of soil organic matter (OM; SOM) in the northern circumpolar region focus on bulk soils. Thus, although there is a plethora of assumptions regarding differences in terms of C turnover or stability, little knowledge is available on the mechanisms stabilizing organic C in Arctic soils besides impaired decomposition due to low temperatures. To gain such knowledge, we investigated soils from Samoylov Island in the Lena River delta with respect to the composition and distribution of organic C among differently stabilized SOM fractions. The soils were fractionated according to density and particle size to obtain differently stabilized SOM fractions differing in chemical composition and thus bioavailability. To better understand the chemical alterations from plant-derived organic particles in these soils rich in fibrous plant residues to mineral-associated SOM, we analyzed the elemental, isotopic and chemical composition of particulate OM (POM) and clay-sized mineral-associated OM (MAOM). We demonstrate that the SOM fractions that contribute with about 17 kg C m −3 for more than 60 % of the C stock are highly bioavailable and that most of this labile C can be assumed to be prone to mineralization under warming conditions. Thus, the amount of relatively stable, small occluded POM and clay-sized MAOM that currently accounts with about 10 kg C m −3 for about 40 % of the C stock will most probably be crucial for the quantity of C protected from mineralization in these Arctic soils in a warmer future. Using δ 15 N as a proxy for nitrogen (N) balances indicated an important role of N inputs by biological N fixation, while gaseous N losses appeared less important. However, this could change, as with about 0.4 kg N m −3 one third of the N is present in bioavailable ... Article in Journal/Newspaper Arctic lena river permafrost Directory of Open Access Journals: DOAJ Articles Arctic Biogeosciences 17 13 3367 3383 |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 I. Prater S. Zubrzycki F. Buegger L. C. Zoor-Füllgraff G. Angst M. Dannenmann C. W. Mueller From fibrous plant residues to mineral-associated organic carbon – the fate of organic matter in Arctic permafrost soils |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
Permafrost-affected soils of the Arctic account for 70 % or 727 Pg of the soil organic carbon (C) stored in the northern circumpolar permafrost region and therefore play a major role in the global C cycle. Most studies on the budgeting of C storage and the quality of soil organic matter (OM; SOM) in the northern circumpolar region focus on bulk soils. Thus, although there is a plethora of assumptions regarding differences in terms of C turnover or stability, little knowledge is available on the mechanisms stabilizing organic C in Arctic soils besides impaired decomposition due to low temperatures. To gain such knowledge, we investigated soils from Samoylov Island in the Lena River delta with respect to the composition and distribution of organic C among differently stabilized SOM fractions. The soils were fractionated according to density and particle size to obtain differently stabilized SOM fractions differing in chemical composition and thus bioavailability. To better understand the chemical alterations from plant-derived organic particles in these soils rich in fibrous plant residues to mineral-associated SOM, we analyzed the elemental, isotopic and chemical composition of particulate OM (POM) and clay-sized mineral-associated OM (MAOM). We demonstrate that the SOM fractions that contribute with about 17 kg C m −3 for more than 60 % of the C stock are highly bioavailable and that most of this labile C can be assumed to be prone to mineralization under warming conditions. Thus, the amount of relatively stable, small occluded POM and clay-sized MAOM that currently accounts with about 10 kg C m −3 for about 40 % of the C stock will most probably be crucial for the quantity of C protected from mineralization in these Arctic soils in a warmer future. Using δ 15 N as a proxy for nitrogen (N) balances indicated an important role of N inputs by biological N fixation, while gaseous N losses appeared less important. However, this could change, as with about 0.4 kg N m −3 one third of the N is present in bioavailable ... |
format |
Article in Journal/Newspaper |
author |
I. Prater S. Zubrzycki F. Buegger L. C. Zoor-Füllgraff G. Angst M. Dannenmann C. W. Mueller |
author_facet |
I. Prater S. Zubrzycki F. Buegger L. C. Zoor-Füllgraff G. Angst M. Dannenmann C. W. Mueller |
author_sort |
I. Prater |
title |
From fibrous plant residues to mineral-associated organic carbon – the fate of organic matter in Arctic permafrost soils |
title_short |
From fibrous plant residues to mineral-associated organic carbon – the fate of organic matter in Arctic permafrost soils |
title_full |
From fibrous plant residues to mineral-associated organic carbon – the fate of organic matter in Arctic permafrost soils |
title_fullStr |
From fibrous plant residues to mineral-associated organic carbon – the fate of organic matter in Arctic permafrost soils |
title_full_unstemmed |
From fibrous plant residues to mineral-associated organic carbon – the fate of organic matter in Arctic permafrost soils |
title_sort |
from fibrous plant residues to mineral-associated organic carbon – the fate of organic matter in arctic permafrost soils |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/bg-17-3367-2020 https://doaj.org/article/3c6c0e75b86a4e60a01636cb3b604b2a |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic lena river permafrost |
genre_facet |
Arctic lena river permafrost |
op_source |
Biogeosciences, Vol 17, Pp 3367-3383 (2020) |
op_relation |
https://www.biogeosciences.net/17/3367/2020/bg-17-3367-2020.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-17-3367-2020 1726-4170 1726-4189 https://doaj.org/article/3c6c0e75b86a4e60a01636cb3b604b2a |
op_doi |
https://doi.org/10.5194/bg-17-3367-2020 |
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Biogeosciences |
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17 |
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13 |
container_start_page |
3367 |
op_container_end_page |
3383 |
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1766326198314467328 |