Methane dynamics in the subarctic tundra: combining stable isotope analyses, plot- and ecosystem-scale flux measurements

Methane (CH 4 ) fluxes were investigated in a subarctic Russian tundra site in a multi-approach study combining plot-scale data, ecosystem-scale eddy covariance (EC) measurements, and a fine-resolution land cover classification scheme for regional upscaling. The flux data as measured by the two inde...

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Published in:Biogeosciences
Main Authors: M. E. Marushchak, T. Friborg, C. Biasi, M. Herbst, T. Johansson, I. Kiepe, M. Liimatainen, S. E. Lind, P. J. Martikainen, T. Virtanen, H. Soegaard, N. J. Shurpali
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2016
Subjects:
Online Access:https://doi.org/10.5194/bg-13-597-2016
https://doaj.org/article/cd4d032cace54290a51451efcc096569
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spelling ftdoajarticles:oai:doaj.org/article:cd4d032cace54290a51451efcc096569 2023-05-15T18:28:21+02:00 Methane dynamics in the subarctic tundra: combining stable isotope analyses, plot- and ecosystem-scale flux measurements M. E. Marushchak T. Friborg C. Biasi M. Herbst T. Johansson I. Kiepe M. Liimatainen S. E. Lind P. J. Martikainen T. Virtanen H. Soegaard N. J. Shurpali 2016-02-01T00:00:00Z https://doi.org/10.5194/bg-13-597-2016 https://doaj.org/article/cd4d032cace54290a51451efcc096569 EN eng Copernicus Publications http://www.biogeosciences.net/13/597/2016/bg-13-597-2016.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-13-597-2016 https://doaj.org/article/cd4d032cace54290a51451efcc096569 Biogeosciences, Vol 13, Iss 2, Pp 597-608 (2016) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2016 ftdoajarticles https://doi.org/10.5194/bg-13-597-2016 2022-12-31T13:35:08Z Methane (CH 4 ) fluxes were investigated in a subarctic Russian tundra site in a multi-approach study combining plot-scale data, ecosystem-scale eddy covariance (EC) measurements, and a fine-resolution land cover classification scheme for regional upscaling. The flux data as measured by the two independent techniques resulted in a seasonal (May–October 2008) cumulative CH 4 emission of 2.4 (EC) and 3.7 g CH 4 m −2 (manual chambers) for the source area representative of the footprint of the EC instruments. Upon upscaling for the entire study region of 98.6 km 2 , the chamber measured flux data yielded a regional flux estimate of 6.7 g CH 4 m −2 yr −1 . Our upscaling efforts accounted for the large spatial variability in the distribution of the various land cover types (LCTs) predominant at our study site. Wetlands with emissions ranging from 34 to 53 g CH 4 m −2 yr −1 were the most dominant CH 4 -emitting surfaces. Emissions from thermokarst lakes were an order of magnitude lower, while the rest of the landscape (mineral tundra) was a weak sink for atmospheric methane. Vascular plant cover was a key factor in explaining the spatial variability of CH 4 emissions among wetland types, as indicated by the positive correlation of emissions with the leaf area index (LAI). As elucidated through a stable isotope analysis, the dominant CH 4 release pathway from wetlands to the atmosphere was plant-mediated diffusion through aerenchyma, a process that discriminates against 13 C-CH 4 . The CH 4 released to the atmosphere was lighter than that in the surface porewater, and δ 13 C in the emitted CH 4 correlated negatively with the vascular plant cover (LAI). The mean value of δ 13 C obtained here for the emitted CH 4 , −68.2 ± 2.0 ‰, is within the range of values from other wetlands, thus reinforcing the use of inverse modelling tools to better constrain the CH 4 budget. Based on the IPCC A1B emission scenario, a temperature increase of 6.1 °C relative to the present day has been predicted for the European Russian tundra by ... Article in Journal/Newspaper Subarctic Thermokarst Tundra Directory of Open Access Journals: DOAJ Articles Biogeosciences 13 2 597 608
institution Open Polar
collection 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
spellingShingle Ecology
QH540-549.5
Life
QH501-531
Geology
QE1-996.5
M. E. Marushchak
T. Friborg
C. Biasi
M. Herbst
T. Johansson
I. Kiepe
M. Liimatainen
S. E. Lind
P. J. Martikainen
T. Virtanen
H. Soegaard
N. J. Shurpali
Methane dynamics in the subarctic tundra: combining stable isotope analyses, plot- and ecosystem-scale flux measurements
topic_facet Ecology
QH540-549.5
Life
QH501-531
Geology
QE1-996.5
description Methane (CH 4 ) fluxes were investigated in a subarctic Russian tundra site in a multi-approach study combining plot-scale data, ecosystem-scale eddy covariance (EC) measurements, and a fine-resolution land cover classification scheme for regional upscaling. The flux data as measured by the two independent techniques resulted in a seasonal (May–October 2008) cumulative CH 4 emission of 2.4 (EC) and 3.7 g CH 4 m −2 (manual chambers) for the source area representative of the footprint of the EC instruments. Upon upscaling for the entire study region of 98.6 km 2 , the chamber measured flux data yielded a regional flux estimate of 6.7 g CH 4 m −2 yr −1 . Our upscaling efforts accounted for the large spatial variability in the distribution of the various land cover types (LCTs) predominant at our study site. Wetlands with emissions ranging from 34 to 53 g CH 4 m −2 yr −1 were the most dominant CH 4 -emitting surfaces. Emissions from thermokarst lakes were an order of magnitude lower, while the rest of the landscape (mineral tundra) was a weak sink for atmospheric methane. Vascular plant cover was a key factor in explaining the spatial variability of CH 4 emissions among wetland types, as indicated by the positive correlation of emissions with the leaf area index (LAI). As elucidated through a stable isotope analysis, the dominant CH 4 release pathway from wetlands to the atmosphere was plant-mediated diffusion through aerenchyma, a process that discriminates against 13 C-CH 4 . The CH 4 released to the atmosphere was lighter than that in the surface porewater, and δ 13 C in the emitted CH 4 correlated negatively with the vascular plant cover (LAI). The mean value of δ 13 C obtained here for the emitted CH 4 , −68.2 ± 2.0 ‰, is within the range of values from other wetlands, thus reinforcing the use of inverse modelling tools to better constrain the CH 4 budget. Based on the IPCC A1B emission scenario, a temperature increase of 6.1 °C relative to the present day has been predicted for the European Russian tundra by ...
format Article in Journal/Newspaper
author M. E. Marushchak
T. Friborg
C. Biasi
M. Herbst
T. Johansson
I. Kiepe
M. Liimatainen
S. E. Lind
P. J. Martikainen
T. Virtanen
H. Soegaard
N. J. Shurpali
author_facet M. E. Marushchak
T. Friborg
C. Biasi
M. Herbst
T. Johansson
I. Kiepe
M. Liimatainen
S. E. Lind
P. J. Martikainen
T. Virtanen
H. Soegaard
N. J. Shurpali
author_sort M. E. Marushchak
title Methane dynamics in the subarctic tundra: combining stable isotope analyses, plot- and ecosystem-scale flux measurements
title_short Methane dynamics in the subarctic tundra: combining stable isotope analyses, plot- and ecosystem-scale flux measurements
title_full Methane dynamics in the subarctic tundra: combining stable isotope analyses, plot- and ecosystem-scale flux measurements
title_fullStr Methane dynamics in the subarctic tundra: combining stable isotope analyses, plot- and ecosystem-scale flux measurements
title_full_unstemmed Methane dynamics in the subarctic tundra: combining stable isotope analyses, plot- and ecosystem-scale flux measurements
title_sort methane dynamics in the subarctic tundra: combining stable isotope analyses, plot- and ecosystem-scale flux measurements
publisher Copernicus Publications
publishDate 2016
url https://doi.org/10.5194/bg-13-597-2016
https://doaj.org/article/cd4d032cace54290a51451efcc096569
genre Subarctic
Thermokarst
Tundra
genre_facet Subarctic
Thermokarst
Tundra
op_source Biogeosciences, Vol 13, Iss 2, Pp 597-608 (2016)
op_relation http://www.biogeosciences.net/13/597/2016/bg-13-597-2016.pdf
https://doaj.org/toc/1726-4170
https://doaj.org/toc/1726-4189
1726-4170
1726-4189
doi:10.5194/bg-13-597-2016
https://doaj.org/article/cd4d032cace54290a51451efcc096569
op_doi https://doi.org/10.5194/bg-13-597-2016
container_title Biogeosciences
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