In-situ Studies of Microbial CH4 Oxidation Efficiency in Arctic Wetland Soils – Application of Stable Carbon Isotopes
Arctic wetland soils are significant sources of the climate-relevant trace gas methane (CH4). The observed accelerated warming of the Arctic is expected to cause deeper permafrost thawing followed by increased carbon mineralization and CH4 formation in water-saturated permafrost-affected tundra soil...
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Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky
2013
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ftsubhamburg:oai:ediss.sub.uni-hamburg.de:ediss/5044 2023-05-15T14:54:27+02:00 In-situ Studies of Microbial CH4 Oxidation Efficiency in Arctic Wetland Soils – Application of Stable Carbon Isotopes In-situ Studien zur mikrobiellen CH4 -Oxidationseffizienz in arktischen Feuchtgebieten - Anwendung von stabilen Kohlenstoffisotopen Preuss, Inken-Marie Pfeiffer, Eva-Maria (Prof. Dr.) 2013-01-01 http://nbn-resolving.de/urn:nbn:de:gbv:18-63312 https://ediss.sub.uni-hamburg.de/handle/ediss/5044 eng eng Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky http://nbn-resolving.de/urn:nbn:de:gbv:18-63312 https://ediss.sub.uni-hamburg.de/handle/ediss/5044 http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess No license Methanumsatz Methanoxidation Stabile Isotopen Diffusion Fraktionierungsfaktor methane turnover polygonal tundra fractionation factor permafrost 550 Geowissenschaften 38.69 Bodenkunde: Sonstiges ddc:550 doctoralThesis doc-type:doctoralThesis 2013 ftsubhamburg 2022-11-09T07:10:56Z Arctic wetland soils are significant sources of the climate-relevant trace gas methane (CH4). The observed accelerated warming of the Arctic is expected to cause deeper permafrost thawing followed by increased carbon mineralization and CH4 formation in water-saturated permafrost-affected tundra soils thus creating a positive feedback to climate change. Aerobic CH4 oxidation is regarded as the key process reducing CH4 emissions from wetlands, but quantification of turnover rates has remained difficult so far. This study improved the in-situ quantification of microbial CH4 oxidation efficiency in arctic wetland soils in Russia’s Lena River Delta based on stable isotope signatures of CH4. In addition to the common practice of determining the stable isotope fractionation during oxidation, additionally the fractionation effect of diffusion, an important gas transport mechanism in tundra soils, was investigated for both saturated and unsaturated conditions. The isotopic fractionation factors αox and αdiff were used to calculate the CH4 oxidation efficiency from the CH4 stable isotope signatures of wet polygonal tundra soils of different hydrology. Further, the method was used to study the short-term effects of temperature increase with a climate manipulation experiment. For the first time, the stable isotope fractionation of CH4 diffusion through water-saturated soils was determined with αdiff = 1.001 ± 0.0002 (n = 3). CH4 stable isotope fractionation during diffusion through air-filled pores of the investigated polygonal tundra soils was αdiff = 1.013 ± 0.003 (n = 18). For the studied sites the fractionation factor for diffusion under saturated conditions αdiff = 1.001 seems to be of utmost importance for the quantification of the CH4 oxidation efficiency, since most of the CH4 is oxidized in the saturated part at the aerobic-anaerobic interface. Furthermore, it was found that αox differs widely between sites and horizons (mean αox = 1.018 ± 0.009) and needs to be determined on a case by case basis. The impact of ... Doctoral or Postdoctoral Thesis Arctic Arktis* Climate change lena river permafrost Tundra ediss.sub.hamburg (Staats- und Universitätsbibliothek Hamburg, Carl von Ossietzky) Arctic |
institution |
Open Polar |
collection |
ediss.sub.hamburg (Staats- und Universitätsbibliothek Hamburg, Carl von Ossietzky) |
op_collection_id |
ftsubhamburg |
language |
English |
topic |
Methanumsatz Methanoxidation Stabile Isotopen Diffusion Fraktionierungsfaktor methane turnover polygonal tundra fractionation factor permafrost 550 Geowissenschaften 38.69 Bodenkunde: Sonstiges ddc:550 |
spellingShingle |
Methanumsatz Methanoxidation Stabile Isotopen Diffusion Fraktionierungsfaktor methane turnover polygonal tundra fractionation factor permafrost 550 Geowissenschaften 38.69 Bodenkunde: Sonstiges ddc:550 Preuss, Inken-Marie In-situ Studies of Microbial CH4 Oxidation Efficiency in Arctic Wetland Soils – Application of Stable Carbon Isotopes |
topic_facet |
Methanumsatz Methanoxidation Stabile Isotopen Diffusion Fraktionierungsfaktor methane turnover polygonal tundra fractionation factor permafrost 550 Geowissenschaften 38.69 Bodenkunde: Sonstiges ddc:550 |
description |
Arctic wetland soils are significant sources of the climate-relevant trace gas methane (CH4). The observed accelerated warming of the Arctic is expected to cause deeper permafrost thawing followed by increased carbon mineralization and CH4 formation in water-saturated permafrost-affected tundra soils thus creating a positive feedback to climate change. Aerobic CH4 oxidation is regarded as the key process reducing CH4 emissions from wetlands, but quantification of turnover rates has remained difficult so far. This study improved the in-situ quantification of microbial CH4 oxidation efficiency in arctic wetland soils in Russia’s Lena River Delta based on stable isotope signatures of CH4. In addition to the common practice of determining the stable isotope fractionation during oxidation, additionally the fractionation effect of diffusion, an important gas transport mechanism in tundra soils, was investigated for both saturated and unsaturated conditions. The isotopic fractionation factors αox and αdiff were used to calculate the CH4 oxidation efficiency from the CH4 stable isotope signatures of wet polygonal tundra soils of different hydrology. Further, the method was used to study the short-term effects of temperature increase with a climate manipulation experiment. For the first time, the stable isotope fractionation of CH4 diffusion through water-saturated soils was determined with αdiff = 1.001 ± 0.0002 (n = 3). CH4 stable isotope fractionation during diffusion through air-filled pores of the investigated polygonal tundra soils was αdiff = 1.013 ± 0.003 (n = 18). For the studied sites the fractionation factor for diffusion under saturated conditions αdiff = 1.001 seems to be of utmost importance for the quantification of the CH4 oxidation efficiency, since most of the CH4 is oxidized in the saturated part at the aerobic-anaerobic interface. Furthermore, it was found that αox differs widely between sites and horizons (mean αox = 1.018 ± 0.009) and needs to be determined on a case by case basis. The impact of ... |
author2 |
Pfeiffer, Eva-Maria (Prof. Dr.) |
format |
Doctoral or Postdoctoral Thesis |
author |
Preuss, Inken-Marie |
author_facet |
Preuss, Inken-Marie |
author_sort |
Preuss, Inken-Marie |
title |
In-situ Studies of Microbial CH4 Oxidation Efficiency in Arctic Wetland Soils – Application of Stable Carbon Isotopes |
title_short |
In-situ Studies of Microbial CH4 Oxidation Efficiency in Arctic Wetland Soils – Application of Stable Carbon Isotopes |
title_full |
In-situ Studies of Microbial CH4 Oxidation Efficiency in Arctic Wetland Soils – Application of Stable Carbon Isotopes |
title_fullStr |
In-situ Studies of Microbial CH4 Oxidation Efficiency in Arctic Wetland Soils – Application of Stable Carbon Isotopes |
title_full_unstemmed |
In-situ Studies of Microbial CH4 Oxidation Efficiency in Arctic Wetland Soils – Application of Stable Carbon Isotopes |
title_sort |
in-situ studies of microbial ch4 oxidation efficiency in arctic wetland soils – application of stable carbon isotopes |
publisher |
Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky |
publishDate |
2013 |
url |
http://nbn-resolving.de/urn:nbn:de:gbv:18-63312 https://ediss.sub.uni-hamburg.de/handle/ediss/5044 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Arktis* Climate change lena river permafrost Tundra |
genre_facet |
Arctic Arktis* Climate change lena river permafrost Tundra |
op_relation |
http://nbn-resolving.de/urn:nbn:de:gbv:18-63312 https://ediss.sub.uni-hamburg.de/handle/ediss/5044 |
op_rights |
http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess No license |
_version_ |
1766326175489064960 |