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Methane Exchange in a Coastal Fen in the First Year after Flooding - A Systems Shift

BACKGROUND: Peatland restoration can have several objectives, for example re-establishing the natural habitat, supporting unique biodiversity attributes or re-initiating key biogeochemical processes, which can ultimately lead to a reduction in greenhouse gas (GHG) emissions. Every restoration measur...

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Autores principales: Hahn, Juliane, Köhler, Stefan, Glatzel, Stephan, Jurasinski, Gerald
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4604153/
https://www.ncbi.nlm.nih.gov/pubmed/26461916
http://dx.doi.org/10.1371/journal.pone.0140657
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author Hahn, Juliane
Köhler, Stefan
Glatzel, Stephan
Jurasinski, Gerald
author_facet Hahn, Juliane
Köhler, Stefan
Glatzel, Stephan
Jurasinski, Gerald
author_sort Hahn, Juliane
collection PubMed
description BACKGROUND: Peatland restoration can have several objectives, for example re-establishing the natural habitat, supporting unique biodiversity attributes or re-initiating key biogeochemical processes, which can ultimately lead to a reduction in greenhouse gas (GHG) emissions. Every restoration measure, however, is itself a disturbance to the ecosystem. METHODS: Here, we examine an ecosystem shift in a coastal fen at the southern Baltic Sea which was rewetted by flooding. The analyses are based on one year of bi-weekly closed chamber measurements of methane fluxes gathered at spots located in different vegetation stands. During measurement campaigns, we recorded data on water levels, peat temperatures, and chemical properties of peat water. In addition we analyzed the first 20 cm of peat before and after flooding for dry bulk density (DBD), content of organic matter and total amounts of carbon (C), nitrogen (N), sulfur (S), and other nutrients. RESULTS: Rewetting turned the site from a summer dry fen into a shallow lake with water levels up to 0.60 m. We observed a substantial die-back of vegetation, especially in stands of sedges (Carex acutiformis Ehrh). Concentrations of total organic carbon and nitrogen in the peat water, as well as dry bulk density and concentrations of C, N and S in the peat increased. In the first year after rewetting, the average annual exchange of methane amounted to 0.26 ± 0.06 kg m(-2). This is equivalent to a 190-times increase in methane compared to pre-flooding conditions. Highest methane fluxes occurred in sedge stands which suffered from the heaviest die-back. None of the recorded environmental variables showed consistent relationships with the amounts of methane exchanged. CONCLUSIONS: Our results suggest that rewetting projects should be monitored not only with regard to vegetation development but also with respect to biogeochemical conditions. Further, high methane emissions that likely occur directly after rewetting by flooding should be considered when forecasting the overall effect of rewetting on GHG exchange.
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spelling pubmed-46041532015-10-20 Methane Exchange in a Coastal Fen in the First Year after Flooding - A Systems Shift Hahn, Juliane Köhler, Stefan Glatzel, Stephan Jurasinski, Gerald PLoS One Research Article BACKGROUND: Peatland restoration can have several objectives, for example re-establishing the natural habitat, supporting unique biodiversity attributes or re-initiating key biogeochemical processes, which can ultimately lead to a reduction in greenhouse gas (GHG) emissions. Every restoration measure, however, is itself a disturbance to the ecosystem. METHODS: Here, we examine an ecosystem shift in a coastal fen at the southern Baltic Sea which was rewetted by flooding. The analyses are based on one year of bi-weekly closed chamber measurements of methane fluxes gathered at spots located in different vegetation stands. During measurement campaigns, we recorded data on water levels, peat temperatures, and chemical properties of peat water. In addition we analyzed the first 20 cm of peat before and after flooding for dry bulk density (DBD), content of organic matter and total amounts of carbon (C), nitrogen (N), sulfur (S), and other nutrients. RESULTS: Rewetting turned the site from a summer dry fen into a shallow lake with water levels up to 0.60 m. We observed a substantial die-back of vegetation, especially in stands of sedges (Carex acutiformis Ehrh). Concentrations of total organic carbon and nitrogen in the peat water, as well as dry bulk density and concentrations of C, N and S in the peat increased. In the first year after rewetting, the average annual exchange of methane amounted to 0.26 ± 0.06 kg m(-2). This is equivalent to a 190-times increase in methane compared to pre-flooding conditions. Highest methane fluxes occurred in sedge stands which suffered from the heaviest die-back. None of the recorded environmental variables showed consistent relationships with the amounts of methane exchanged. CONCLUSIONS: Our results suggest that rewetting projects should be monitored not only with regard to vegetation development but also with respect to biogeochemical conditions. Further, high methane emissions that likely occur directly after rewetting by flooding should be considered when forecasting the overall effect of rewetting on GHG exchange. Public Library of Science 2015-10-13 /pmc/articles/PMC4604153/ /pubmed/26461916 http://dx.doi.org/10.1371/journal.pone.0140657 Text en © 2015 Hahn et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Hahn, Juliane
Köhler, Stefan
Glatzel, Stephan
Jurasinski, Gerald
Methane Exchange in a Coastal Fen in the First Year after Flooding - A Systems Shift
title Methane Exchange in a Coastal Fen in the First Year after Flooding - A Systems Shift
title_full Methane Exchange in a Coastal Fen in the First Year after Flooding - A Systems Shift
title_fullStr Methane Exchange in a Coastal Fen in the First Year after Flooding - A Systems Shift
title_full_unstemmed Methane Exchange in a Coastal Fen in the First Year after Flooding - A Systems Shift
title_short Methane Exchange in a Coastal Fen in the First Year after Flooding - A Systems Shift
title_sort methane exchange in a coastal fen in the first year after flooding - a systems shift
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4604153/
https://www.ncbi.nlm.nih.gov/pubmed/26461916
http://dx.doi.org/10.1371/journal.pone.0140657
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