Influences of Hillslope Biogeochemistry on Anaerobic Soil Organic Matter Decomposition in a Tundra Watershed
We investigated rates and controls on greenhouse gas (CO2 and CH4) production in two contrasting water‐saturated tundra soils within a permafrost‐affected watershed near Nome, Alaska, United States. Three years of field sample analysis have shown that soil from a fen‐like area in the toeslope of the...
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ftolddominionuni:oai:digitalcommons.odu.edu:chemistry_fac_pubs-1192 2023-05-15T15:13:21+02:00 Influences of Hillslope Biogeochemistry on Anaerobic Soil Organic Matter Decomposition in a Tundra Watershed Philben, Michael Taş, Neslihan Chen, Hongmei Wullschleger, Stan D. Kholodov, Alexander Graham, David E. Gu, Baohua 2020-01-01T08:00:00Z application/pdf https://digitalcommons.odu.edu/chemistry_fac_pubs/188 https://digitalcommons.odu.edu/cgi/viewcontent.cgi?article=1192&context=chemistry_fac_pubs unknown ODU Digital Commons https://digitalcommons.odu.edu/chemistry_fac_pubs/188 https://digitalcommons.odu.edu/cgi/viewcontent.cgi?article=1192&context=chemistry_fac_pubs Chemistry & Biochemistry Faculty Publications Greenhouse gas mitigation Humus Watersheds Alkalinity Biogeochemistry Arctic Hillslope biogeochemistry Methane Microbial nitrogen limitation Permafrost Chemistry Organic Chemistry article 2020 ftolddominionuni 2021-08-30T17:41:00Z We investigated rates and controls on greenhouse gas (CO2 and CH4) production in two contrasting water‐saturated tundra soils within a permafrost‐affected watershed near Nome, Alaska, United States. Three years of field sample analysis have shown that soil from a fen‐like area in the toeslope of the watershed had higher pH and higher porewater ion concentrations than soil collected from a bog‐like peat plateau at the top of the hillslope. The influence of these contrasting geochemical and topographic environments on CO2 and CH4 production was tested in soil microcosms by incubating both the organic‐ and mineral‐layer soils anaerobically for 55 days. Nitrogen (as NH4Cl) was added to half of the microcosms to test potential effects of N limitation on microbial greenhouse gas production. We found that the organic toeslope soils produced more CO2 and CH4, fueled by higher pH and higher concentrations of water‐extractable organic C (WEOC). Our results also indicate N limitation on CO2 production in the peat plateau soils but not the toeslope soils. Together these results suggest that the weathering and leaching of ions and nutrients from tundra hillslopes can increase the rate of anaerobic soil organic matter decomposition in downslope soils by (1) increasing the pH of soil porewater; (2) providing bioavailable WEOC and fermentation products such as acetate; and (3) relieving microbial N limitation through nutrient runoff. We conclude that the soil geochemistry as mediated by landscape position is an important factor influencing the rate and magnitude of greenhouse gas production in tundra soils. Article in Journal/Newspaper Arctic Nome Peat Peat plateau permafrost Tundra Alaska Old Dominion University: ODU Digital Commons Arctic |
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Open Polar |
collection |
Old Dominion University: ODU Digital Commons |
op_collection_id |
ftolddominionuni |
language |
unknown |
topic |
Greenhouse gas mitigation Humus Watersheds Alkalinity Biogeochemistry Arctic Hillslope biogeochemistry Methane Microbial nitrogen limitation Permafrost Chemistry Organic Chemistry |
spellingShingle |
Greenhouse gas mitigation Humus Watersheds Alkalinity Biogeochemistry Arctic Hillslope biogeochemistry Methane Microbial nitrogen limitation Permafrost Chemistry Organic Chemistry Philben, Michael Taş, Neslihan Chen, Hongmei Wullschleger, Stan D. Kholodov, Alexander Graham, David E. Gu, Baohua Influences of Hillslope Biogeochemistry on Anaerobic Soil Organic Matter Decomposition in a Tundra Watershed |
topic_facet |
Greenhouse gas mitigation Humus Watersheds Alkalinity Biogeochemistry Arctic Hillslope biogeochemistry Methane Microbial nitrogen limitation Permafrost Chemistry Organic Chemistry |
description |
We investigated rates and controls on greenhouse gas (CO2 and CH4) production in two contrasting water‐saturated tundra soils within a permafrost‐affected watershed near Nome, Alaska, United States. Three years of field sample analysis have shown that soil from a fen‐like area in the toeslope of the watershed had higher pH and higher porewater ion concentrations than soil collected from a bog‐like peat plateau at the top of the hillslope. The influence of these contrasting geochemical and topographic environments on CO2 and CH4 production was tested in soil microcosms by incubating both the organic‐ and mineral‐layer soils anaerobically for 55 days. Nitrogen (as NH4Cl) was added to half of the microcosms to test potential effects of N limitation on microbial greenhouse gas production. We found that the organic toeslope soils produced more CO2 and CH4, fueled by higher pH and higher concentrations of water‐extractable organic C (WEOC). Our results also indicate N limitation on CO2 production in the peat plateau soils but not the toeslope soils. Together these results suggest that the weathering and leaching of ions and nutrients from tundra hillslopes can increase the rate of anaerobic soil organic matter decomposition in downslope soils by (1) increasing the pH of soil porewater; (2) providing bioavailable WEOC and fermentation products such as acetate; and (3) relieving microbial N limitation through nutrient runoff. We conclude that the soil geochemistry as mediated by landscape position is an important factor influencing the rate and magnitude of greenhouse gas production in tundra soils. |
format |
Article in Journal/Newspaper |
author |
Philben, Michael Taş, Neslihan Chen, Hongmei Wullschleger, Stan D. Kholodov, Alexander Graham, David E. Gu, Baohua |
author_facet |
Philben, Michael Taş, Neslihan Chen, Hongmei Wullschleger, Stan D. Kholodov, Alexander Graham, David E. Gu, Baohua |
author_sort |
Philben, Michael |
title |
Influences of Hillslope Biogeochemistry on Anaerobic Soil Organic Matter Decomposition in a Tundra Watershed |
title_short |
Influences of Hillslope Biogeochemistry on Anaerobic Soil Organic Matter Decomposition in a Tundra Watershed |
title_full |
Influences of Hillslope Biogeochemistry on Anaerobic Soil Organic Matter Decomposition in a Tundra Watershed |
title_fullStr |
Influences of Hillslope Biogeochemistry on Anaerobic Soil Organic Matter Decomposition in a Tundra Watershed |
title_full_unstemmed |
Influences of Hillslope Biogeochemistry on Anaerobic Soil Organic Matter Decomposition in a Tundra Watershed |
title_sort |
influences of hillslope biogeochemistry on anaerobic soil organic matter decomposition in a tundra watershed |
publisher |
ODU Digital Commons |
publishDate |
2020 |
url |
https://digitalcommons.odu.edu/chemistry_fac_pubs/188 https://digitalcommons.odu.edu/cgi/viewcontent.cgi?article=1192&context=chemistry_fac_pubs |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Nome Peat Peat plateau permafrost Tundra Alaska |
genre_facet |
Arctic Nome Peat Peat plateau permafrost Tundra Alaska |
op_source |
Chemistry & Biochemistry Faculty Publications |
op_relation |
https://digitalcommons.odu.edu/chemistry_fac_pubs/188 https://digitalcommons.odu.edu/cgi/viewcontent.cgi?article=1192&context=chemistry_fac_pubs |
_version_ |
1766343917904592896 |