Water-table height and microtopography control biogeochemical cycling in an Arctic coastal tundra ecosystem
Drained thaw lake basins (DTLB's) are the dominant land form of the Arctic Coastal Plain in northern Alaska. The presence of continuous permafrost prevents drainage and so water tables generally remain close to the soil surface, creating saturated, suboxic soil conditions. However, ice wedge po...
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ftdoajarticles:oai:doaj.org/article:7d56cc2c124145c18988740e27cc2916 2023-05-15T14:56:42+02:00 Water-table height and microtopography control biogeochemical cycling in an Arctic coastal tundra ecosystem D. A. Lipson D. Zona T. K. Raab F. Bozzolo M. Mauritz W. C. Oechel 2012-01-01T00:00:00Z https://doi.org/10.5194/bg-9-577-2012 https://doaj.org/article/7d56cc2c124145c18988740e27cc2916 EN eng Copernicus Publications http://www.biogeosciences.net/9/577/2012/bg-9-577-2012.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-9-577-2012 https://doaj.org/article/7d56cc2c124145c18988740e27cc2916 Biogeosciences, Vol 9, Iss 1, Pp 577-591 (2012) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2012 ftdoajarticles https://doi.org/10.5194/bg-9-577-2012 2022-12-31T14:07:26Z Drained thaw lake basins (DTLB's) are the dominant land form of the Arctic Coastal Plain in northern Alaska. The presence of continuous permafrost prevents drainage and so water tables generally remain close to the soil surface, creating saturated, suboxic soil conditions. However, ice wedge polygons produce microtopographic variation in these landscapes, with raised areas such as polygon rims creating more oxic microenvironments. The peat soils in this ecosystem store large amounts of organic carbon which is vulnerable to loss as arctic regions continue to rapidly warm, and so there is great motivation to understand the controls over microbial activity in these complex landscapes. Here we report the effects of experimental flooding, along with seasonal and spatial variation in soil chemistry and microbial activity in a DTLB. The flooding treatment generally mirrored the effects of natural landscape variation in water-table height due to microtopography. The flooded portion of the basin had lower dissolved oxygen, lower oxidation-reduction potential (ORP) and higher pH, as did lower elevation areas throughout the entire basin. Similarly, soil pore water concentrations of organic carbon and aromatic compounds were higher in flooded and low elevation areas. Dissolved ferric iron (Fe(III)) concentrations were higher in low elevation areas and responded to the flooding treatment in low areas, only. The high concentrations of soluble Fe(III) in soil pore water were explained by the presence of siderophores, which were much more concentrated in low elevation areas. All the aforementioned variables were correlated, showing that Fe(III) is solubilized in response to anoxic conditions. Dissolved carbon dioxide (CO 2 ) and methane (CH 4 ) concentrations were higher in low elevation areas, but showed only subtle and/or seasonally dependent effects of flooding. In anaerobic laboratory incubations, more CH 4 was produced by soils from low and flooded areas, whereas anaerobic CO 2 production only responded to flooding in high ... Article in Journal/Newspaper Arctic Ice permafrost Tundra wedge* Alaska Directory of Open Access Journals: DOAJ Articles Arctic Biogeosciences 9 1 577 591 |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
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Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 D. A. Lipson D. Zona T. K. Raab F. Bozzolo M. Mauritz W. C. Oechel Water-table height and microtopography control biogeochemical cycling in an Arctic coastal tundra ecosystem |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
Drained thaw lake basins (DTLB's) are the dominant land form of the Arctic Coastal Plain in northern Alaska. The presence of continuous permafrost prevents drainage and so water tables generally remain close to the soil surface, creating saturated, suboxic soil conditions. However, ice wedge polygons produce microtopographic variation in these landscapes, with raised areas such as polygon rims creating more oxic microenvironments. The peat soils in this ecosystem store large amounts of organic carbon which is vulnerable to loss as arctic regions continue to rapidly warm, and so there is great motivation to understand the controls over microbial activity in these complex landscapes. Here we report the effects of experimental flooding, along with seasonal and spatial variation in soil chemistry and microbial activity in a DTLB. The flooding treatment generally mirrored the effects of natural landscape variation in water-table height due to microtopography. The flooded portion of the basin had lower dissolved oxygen, lower oxidation-reduction potential (ORP) and higher pH, as did lower elevation areas throughout the entire basin. Similarly, soil pore water concentrations of organic carbon and aromatic compounds were higher in flooded and low elevation areas. Dissolved ferric iron (Fe(III)) concentrations were higher in low elevation areas and responded to the flooding treatment in low areas, only. The high concentrations of soluble Fe(III) in soil pore water were explained by the presence of siderophores, which were much more concentrated in low elevation areas. All the aforementioned variables were correlated, showing that Fe(III) is solubilized in response to anoxic conditions. Dissolved carbon dioxide (CO 2 ) and methane (CH 4 ) concentrations were higher in low elevation areas, but showed only subtle and/or seasonally dependent effects of flooding. In anaerobic laboratory incubations, more CH 4 was produced by soils from low and flooded areas, whereas anaerobic CO 2 production only responded to flooding in high ... |
format |
Article in Journal/Newspaper |
author |
D. A. Lipson D. Zona T. K. Raab F. Bozzolo M. Mauritz W. C. Oechel |
author_facet |
D. A. Lipson D. Zona T. K. Raab F. Bozzolo M. Mauritz W. C. Oechel |
author_sort |
D. A. Lipson |
title |
Water-table height and microtopography control biogeochemical cycling in an Arctic coastal tundra ecosystem |
title_short |
Water-table height and microtopography control biogeochemical cycling in an Arctic coastal tundra ecosystem |
title_full |
Water-table height and microtopography control biogeochemical cycling in an Arctic coastal tundra ecosystem |
title_fullStr |
Water-table height and microtopography control biogeochemical cycling in an Arctic coastal tundra ecosystem |
title_full_unstemmed |
Water-table height and microtopography control biogeochemical cycling in an Arctic coastal tundra ecosystem |
title_sort |
water-table height and microtopography control biogeochemical cycling in an arctic coastal tundra ecosystem |
publisher |
Copernicus Publications |
publishDate |
2012 |
url |
https://doi.org/10.5194/bg-9-577-2012 https://doaj.org/article/7d56cc2c124145c18988740e27cc2916 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Ice permafrost Tundra wedge* Alaska |
genre_facet |
Arctic Ice permafrost Tundra wedge* Alaska |
op_source |
Biogeosciences, Vol 9, Iss 1, Pp 577-591 (2012) |
op_relation |
http://www.biogeosciences.net/9/577/2012/bg-9-577-2012.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-9-577-2012 https://doaj.org/article/7d56cc2c124145c18988740e27cc2916 |
op_doi |
https://doi.org/10.5194/bg-9-577-2012 |
container_title |
Biogeosciences |
container_volume |
9 |
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1 |
container_start_page |
577 |
op_container_end_page |
591 |
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1766328787540115456 |