Ecosystem respiration during snowmelt and soil thaw leads to a rare annual CO₂ net loss in a boreal fen
Rattachement africain : fi, dk, gl. Niveau de preuve : code pays fourni par la source.
Le résumé fourni par la source
Abstract. Although boreal peatlands play a critical role in the global carbon cycle, their year-round carbon dioxide (CO₂) dynamics — and particularly the contribution of the non-growing season (NGS) — remain poorly constrained in annual balance estimates. Using 17 years (2005–2021) of eddy covariance measurements from a fen in southern Finland, we first quantified the magnitude, timing, and interannual variability of CO₂ fluxes. We then examined in greater detail the NGS, with particular emphasis on soil temperature dynamics and the role of thermal legacy effects. On average, the NGS accounted for 60 % of the year (226 ± 27 days), ranging from mid-September to late April, and offset 57 % of the subsequent growing season’s (GS) CO₂ uptake. NGS emissions declined from autumn to spring, with the highest carbon emissions occurring across September–December and the lowest in January–February. Soil temperature—both concurrent and lagged up to four months—was the main control of CO₂ fluxes during November–December and spring thaw, while photosynthetically active radiation (PAR) dominated during the onset of the NGS. Variability in annual CO₂ balances was large, and in two years (2016 and 2018) the fen switched from a net CO₂ sink to a source. Finally, we focused on 2016 in detail: an exceptional six-week CO₂ release during April–May released 84 g C m⁻², offsetting 38 % of the following GS CO₂ uptake. This event was linked to unusually warm late-autumn soils, minimal snow insulation, and subsequent rapid surface freezing, which likely enhanced CO₂ accumulation and stimulated CO₂ release during thaw. Our results demonstrate that short-lived but intense NGS events can determine the annual peatland CO₂ balance and therefore significantly affect the annual carbon budget of boreal peatlands.
Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.
Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé ; titre concordant.
- Titre Crossref
- Ecosystem respiration during snowmelt and soil thaw leads to a rare annual CO₂ net loss in a boreal fen
- Date Crossref
- 11/12/2025
- Éditeur
- Copernicus GmbH
- Type
- posted-content
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
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University of Oulu Energy and Environmental Engineering Research Unit pays non établi dans la noticeUniversité ou école supérieure
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University of Helsinki Institute for Atmospheric and Earth System Research pays non établi dans la noticeUniversité ou école supérieure
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Aarhus University Department of Ecoscience and Arctic Research Centre pays non établi dans la noticeUniversité ou école supérieure
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Finnish Meteorological Institute pays non établi dans la noticeOrganisme public
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University of Eastern Finland pays non établi dans la noticeUniversité ou école supérieure
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Grønlands Naturinstitut pays non établi dans la noticeStructure de recherche
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School of Forest Sciences pays non établi dans la noticeUniversité ou école supérieure
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Department of Environment and Minerals pays non établi dans la noticeStructure de recherche
Energy and Environmental Engineering Research Unit — University of Oulu, Institute for Atmospheric and Earth System Research — University of Helsinki et Department of Ecoscience and Arctic Research Centre — Aarhus University, avec 5 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.