Freeze-thaw cycles simultaneously decrease peatland photosynthetic carbon uptake and ecosystem respiration - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Boreal Environment Research Année : 2017

Freeze-thaw cycles simultaneously decrease peatland photosynthetic carbon uptake and ecosystem respiration

Martin Küttim
Maaike L Hofsommer
  • Fonction : Auteur
Bjorn Robroek
Vincent Jassey
Anna M Laine
  • Fonction : Auteur
Mati Ilomets
  • Fonction : Auteur

Résumé

Decreasing snow cover in winter resulting from climate warming increases the incidence of freeze-thaw cycles (FTCs) in many ecosystems, including peatlands. As peatland ecosystems form a globally significant long-term carbon storage, understanding the effects of changing conditions in winter on carbon dynamics is essential. We studied how FTCs affect peatland carbon cycling by conducting mesocosm experiments with Sphagnum. Our results indicate an overall impeding effect of FTCs on Sphagnum photosynthesis, chlorophyll content, ecosystem respiration and enzymatic processes. A threefold reduction in photosynthesis in the FTC treatment was related to a decrease in chlorophyll content, showing that Sphagnum physiologically suffers from repeated FTCs. In the FTC treatment β-glucosidase and phosphatase enzymatic activities decreased by 50% and 30%, respectively , whilst alanine remained unaffected, indicating that in peat soils short-term FTCs affect the carbon and phosphorus cycles, but not the nitrogen cycle. Long-term effects of FTCs deserve further studies.
Fichier principal
Vignette du fichier
Kuttim2017_ber22-267-276.pdf (309.97 Ko) Télécharger le fichier
Origine Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

hal-02466188 , version 1 (04-02-2020)

Identifiants

  • HAL Id : hal-02466188 , version 1

Citer

Martin Küttim, Maaike L Hofsommer, Bjorn Robroek, Vincent Jassey, Anna M Laine, et al.. Freeze-thaw cycles simultaneously decrease peatland photosynthetic carbon uptake and ecosystem respiration. Boreal Environment Research, 2017. ⟨hal-02466188⟩
143 Consultations
73 Téléchargements

Partager

Gmail Mastodon Facebook X LinkedIn More