Influences of Hillslope Biogeochemistry on Anaerobic Soil Organic Matter Decomposition in a Tundra Watershed
In this work, we investigated rates and controls on greenhouse gas (CO 2 and CH 4 ) 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 th...
Published in: | Journal of Geophysical Research: Biogeosciences |
---|---|
Main Authors: | , , , , , , |
Language: | unknown |
Published: |
2021
|
Subjects: | |
Online Access: | http://www.osti.gov/servlets/purl/1649477 https://www.osti.gov/biblio/1649477 https://doi.org/10.1029/2019jg005512 |
id |
ftosti:oai:osti.gov:1649477 |
---|---|
record_format |
openpolar |
spelling |
ftosti:oai:osti.gov:1649477 2023-07-30T04:05:04+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 2021-07-12 application/pdf http://www.osti.gov/servlets/purl/1649477 https://www.osti.gov/biblio/1649477 https://doi.org/10.1029/2019jg005512 unknown http://www.osti.gov/servlets/purl/1649477 https://www.osti.gov/biblio/1649477 https://doi.org/10.1029/2019jg005512 doi:10.1029/2019jg005512 58 GEOSCIENCES 2021 ftosti https://doi.org/10.1029/2019jg005512 2023-07-11T09:45:20Z In this work, we investigated rates and controls on greenhouse gas (CO 2 and CH 4 ) 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 CO 2 and CH 4 production was tested in soil microcosms by incubating both the organic- and mineral-layer soils anaerobically for 55days. Additionally, nitrogen (as NH 4 Cl) 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 CO 2 and CH 4 , fueled by higher pH and higher concentrations of water-extractable organic C (WEOC). Our results also indicate N limitation on CO 2 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. Other/Unknown Material Nome Peat Peat plateau permafrost Tundra Alaska SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Journal of Geophysical Research: Biogeosciences 125 7 |
institution |
Open Polar |
collection |
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
topic |
58 GEOSCIENCES |
spellingShingle |
58 GEOSCIENCES 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 |
58 GEOSCIENCES |
description |
In this work, we investigated rates and controls on greenhouse gas (CO 2 and CH 4 ) 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 CO 2 and CH 4 production was tested in soil microcosms by incubating both the organic- and mineral-layer soils anaerobically for 55days. Additionally, nitrogen (as NH 4 Cl) 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 CO 2 and CH 4 , fueled by higher pH and higher concentrations of water-extractable organic C (WEOC). Our results also indicate N limitation on CO 2 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. |
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 |
publishDate |
2021 |
url |
http://www.osti.gov/servlets/purl/1649477 https://www.osti.gov/biblio/1649477 https://doi.org/10.1029/2019jg005512 |
genre |
Nome Peat Peat plateau permafrost Tundra Alaska |
genre_facet |
Nome Peat Peat plateau permafrost Tundra Alaska |
op_relation |
http://www.osti.gov/servlets/purl/1649477 https://www.osti.gov/biblio/1649477 https://doi.org/10.1029/2019jg005512 doi:10.1029/2019jg005512 |
op_doi |
https://doi.org/10.1029/2019jg005512 |
container_title |
Journal of Geophysical Research: Biogeosciences |
container_volume |
125 |
container_issue |
7 |
_version_ |
1772816774990921728 |