Metabolism overrides photo-oxidation in CO2 dynamics of Arctic permafrost streams
Global warming is enhancing the mobilization of organic carbon (C) from Arctic soils into streams, where it can be mineralized to CO2 and released to the atmosphere. Abiotic photo‐oxidation might drive C mineralization, but this process has not been quantitatively integrated with biological processe...
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Umeå universitet, Institutionen för ekologi, miljö och geovetenskap
2021
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Online Access: | http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-158881 https://doi.org/10.1002/lno.11564 |
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ftumeauniv:oai:DiVA.org:umu-158881 2023-10-09T21:48:16+02:00 Metabolism overrides photo-oxidation in CO2 dynamics of Arctic permafrost streams Rocher-Ros, Gerard Harms, Tamara K. Sponseller, Ryan A. Väisänen, Maria Mörth, Carl-Magnus Giesler, Reiner 2021 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-158881 https://doi.org/10.1002/lno.11564 eng eng Umeå universitet, Institutionen för ekologi, miljö och geovetenskap Limnology and Oceanography, 0024-3590, 2021, 66:S1, s. S169-S181 orcid:0000-0001-7853-2531 orcid:0000-0002-5758-2705 orcid:0000-0002-6381-4509 http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-158881 doi:10.1002/lno.11564 ISI:000551565700001 Scopus 2-s2.0-85088381437 info:eu-repo/semantics/openAccess Environmental Sciences Miljövetenskap Geosciences Multidisciplinary Multidisciplinär geovetenskap Article in journal info:eu-repo/semantics/article text 2021 ftumeauniv https://doi.org/10.1002/lno.11564 2023-09-22T13:54:16Z Global warming is enhancing the mobilization of organic carbon (C) from Arctic soils into streams, where it can be mineralized to CO2 and released to the atmosphere. Abiotic photo‐oxidation might drive C mineralization, but this process has not been quantitatively integrated with biological processes that also influence CO2 dynamics in aquatic ecosystems. We measured CO2 concentrations and the isotopic composition of dissolved inorganic C (δ13CDIC) at diel resolution in two Arctic streams, and coupled this with whole‐system metabolism estimates to assess the effect of biotic and abiotic processes on stream C dynamics. CO2 concentrations consistently decreased from night to day, a pattern counter to the hypothesis that photo‐oxidation is the dominant source of CO2. Instead, the observed decrease in CO2 during daytime was explained by photosynthetic rates, which were strongly correlated with diurnal changes in δ13CDIC values. However, on days when modeled photosynthetic rates were near zero, there was still a significant diel change in δ13CDIC values, suggesting that metabolic estimates are partly masked by O2 consumption from photo‐oxidation. Our results suggest that 6–12 mmol CO2‐C m−2 d−1 may be generated from photo‐oxidation, a range that corresponds well to previous laboratory measurements. Moreover, ecosystem respiration rates were 10 times greater than published photo‐oxidation rates for these Arctic streams, and accounted for 33–80% of total CO2 evasion. Our results suggest that metabolic activity is the dominant process for CO2 production in Arctic streams. Thus, future aquatic CO2 emissions may depend on how biotic processes respond to the ongoing environmental change. Originally included in thesis in manuscript form with title: "Photosynthesis overrides photo-oxidation in CO 2 dynamics of Arctic permafrost streams" Article in Journal/Newspaper Arctic Global warming permafrost Umeå University: Publications (DiVA) Arctic Limnology and Oceanography 66 S1 |
institution |
Open Polar |
collection |
Umeå University: Publications (DiVA) |
op_collection_id |
ftumeauniv |
language |
English |
topic |
Environmental Sciences Miljövetenskap Geosciences Multidisciplinary Multidisciplinär geovetenskap |
spellingShingle |
Environmental Sciences Miljövetenskap Geosciences Multidisciplinary Multidisciplinär geovetenskap Rocher-Ros, Gerard Harms, Tamara K. Sponseller, Ryan A. Väisänen, Maria Mörth, Carl-Magnus Giesler, Reiner Metabolism overrides photo-oxidation in CO2 dynamics of Arctic permafrost streams |
topic_facet |
Environmental Sciences Miljövetenskap Geosciences Multidisciplinary Multidisciplinär geovetenskap |
description |
Global warming is enhancing the mobilization of organic carbon (C) from Arctic soils into streams, where it can be mineralized to CO2 and released to the atmosphere. Abiotic photo‐oxidation might drive C mineralization, but this process has not been quantitatively integrated with biological processes that also influence CO2 dynamics in aquatic ecosystems. We measured CO2 concentrations and the isotopic composition of dissolved inorganic C (δ13CDIC) at diel resolution in two Arctic streams, and coupled this with whole‐system metabolism estimates to assess the effect of biotic and abiotic processes on stream C dynamics. CO2 concentrations consistently decreased from night to day, a pattern counter to the hypothesis that photo‐oxidation is the dominant source of CO2. Instead, the observed decrease in CO2 during daytime was explained by photosynthetic rates, which were strongly correlated with diurnal changes in δ13CDIC values. However, on days when modeled photosynthetic rates were near zero, there was still a significant diel change in δ13CDIC values, suggesting that metabolic estimates are partly masked by O2 consumption from photo‐oxidation. Our results suggest that 6–12 mmol CO2‐C m−2 d−1 may be generated from photo‐oxidation, a range that corresponds well to previous laboratory measurements. Moreover, ecosystem respiration rates were 10 times greater than published photo‐oxidation rates for these Arctic streams, and accounted for 33–80% of total CO2 evasion. Our results suggest that metabolic activity is the dominant process for CO2 production in Arctic streams. Thus, future aquatic CO2 emissions may depend on how biotic processes respond to the ongoing environmental change. Originally included in thesis in manuscript form with title: "Photosynthesis overrides photo-oxidation in CO 2 dynamics of Arctic permafrost streams" |
format |
Article in Journal/Newspaper |
author |
Rocher-Ros, Gerard Harms, Tamara K. Sponseller, Ryan A. Väisänen, Maria Mörth, Carl-Magnus Giesler, Reiner |
author_facet |
Rocher-Ros, Gerard Harms, Tamara K. Sponseller, Ryan A. Väisänen, Maria Mörth, Carl-Magnus Giesler, Reiner |
author_sort |
Rocher-Ros, Gerard |
title |
Metabolism overrides photo-oxidation in CO2 dynamics of Arctic permafrost streams |
title_short |
Metabolism overrides photo-oxidation in CO2 dynamics of Arctic permafrost streams |
title_full |
Metabolism overrides photo-oxidation in CO2 dynamics of Arctic permafrost streams |
title_fullStr |
Metabolism overrides photo-oxidation in CO2 dynamics of Arctic permafrost streams |
title_full_unstemmed |
Metabolism overrides photo-oxidation in CO2 dynamics of Arctic permafrost streams |
title_sort |
metabolism overrides photo-oxidation in co2 dynamics of arctic permafrost streams |
publisher |
Umeå universitet, Institutionen för ekologi, miljö och geovetenskap |
publishDate |
2021 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-158881 https://doi.org/10.1002/lno.11564 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Global warming permafrost |
genre_facet |
Arctic Global warming permafrost |
op_relation |
Limnology and Oceanography, 0024-3590, 2021, 66:S1, s. S169-S181 orcid:0000-0001-7853-2531 orcid:0000-0002-5758-2705 orcid:0000-0002-6381-4509 http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-158881 doi:10.1002/lno.11564 ISI:000551565700001 Scopus 2-s2.0-85088381437 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1002/lno.11564 |
container_title |
Limnology and Oceanography |
container_volume |
66 |
container_issue |
S1 |
_version_ |
1779311317290582016 |