Digitala Vetenskapliga Arkivet

Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Metabolism overrides photo-oxidation in CO2 dynamics of Arctic permafrost streams
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. (Arcum)ORCID iD: 0000-0001-7853-2531
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. (Arcum)ORCID iD: 0000-0002-5758-2705
Show others and affiliations
2021 (English)In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 66, no S1, p. S169-S181Article in journal (Refereed) Published
Abstract [en]

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.

Place, publisher, year, edition, pages
John Wiley & Sons, 2021. Vol. 66, no S1, p. S169-S181
National Category
Environmental Sciences Geosciences, Multidisciplinary
Identifiers
URN: urn:nbn:se:umu:diva-158881DOI: 10.1002/lno.11564ISI: 000551565700001Scopus ID: 2-s2.0-85088381437OAI: oai:DiVA.org:umu-158881DiVA, id: diva2:1315363
Funder
Swedish Research Council Formas, 2014‐00970, 730938Swedish Research Council, 2013‐5001
Note

Originally included in thesis in manuscript form with title: "Photosynthesis overrides photo-oxidation in CO2 dynamics of Arctic permafrost streams"

Available from: 2019-05-13 Created: 2019-05-13 Last updated: 2021-07-07Bibliographically approved
In thesis
1. Biophysical controls on CO2 evasion from Arctic inland waters
Open this publication in new window or tab >>Biophysical controls on CO2 evasion from Arctic inland waters
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

CO2 evasion to the atmosphere from inland waters is a major component of the global carbon (C) cycle. Yet spatial patterns of CO2 evasion and the sources of C that fuel evasion remain poorly understood. In this thesis, I use detailed measurements of biological and physical drivers of CO2 evasion to assess how C is transformed and evaded from inland waters in the Arctic (Northern Scandinavia and Alaska). I found that lake size was a master variable controlling lake CO2 evasion in an Arctic catchment and that large lakes play a major role at the landscape scale. In stream networks, I found that catchment topography shapes patterns of CO2 evasion by dictating unique domains with high lateral inputs of C, other domains where biological processes were dominant, and domains where physical forces promoted degassing to the atmosphere. Together, these topographically driven domains created a strong spatial heterogeneity that biases regional and global estimates of CO2 evasion. Further, I found that photosynthetic activity in Arctic streams can produce a large change in CO2 concentrations from night to day, and as a result CO2 evasion is up to 45% higher during night than day. The magnitude of the diel change in CO2 was also affected by the turbulence of the stream and photo-chemical production of CO2. Overall, this thesis offers important insights to better understand landscape patterns of CO2 evasion from inland waters, and suggests that stream metabolic processes largely determine the fate of the C delivered from Arctic soils.

Place, publisher, year, edition, pages
Umeå: Umeå University, 2019. p. 32
Keywords
Inland waters, carbon dioxide, organic carbon, inorganic carbon, arctic, CO2 evasion, DOC, DIC, streams, metabolism, oxygen
National Category
Physical Geography Geosciences, Multidisciplinary Environmental Sciences
Research subject
Limnology
Identifiers
urn:nbn:se:umu:diva-158882 (URN)978-91-7855-075-3 (ISBN)
Public defence
2019-06-14, Carl Kempe Salen, KBC, Umeå University, Umeå, 09:30 (English)
Opponent
Supervisors
Available from: 2019-05-24 Created: 2019-05-13 Last updated: 2021-08-17Bibliographically approved

Open Access in DiVA

fulltext(1050 kB)155 downloads
File information
File name FULLTEXT02.pdfFile size 1050 kBChecksum SHA-512
7636a579c452b140e24ff4cc4d6ab8cceac1e36c1c82dab7deb52901968cd390ca2e6753c044da28dd0a22d936e8343d022f632c6e85f5ec68d0721e99fe3d72
Type fulltextMimetype application/pdf

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Rocher-Ros, GerardSponseller, Ryan A.Giesler, Reiner
By organisation
Department of Ecology and Environmental Sciences
In the same journal
Limnology and Oceanography
Environmental SciencesGeosciences, Multidisciplinary

Search outside of DiVA

GoogleGoogle Scholar
Total: 235 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 594 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf