- Delarue, Frederic
- Buttler, Alexandre
- Bragazza, Luca
- Grasset, Laurent
- Jassey, Vincent E. J.
- Gogo, Sebastien
- Laggoun-Defarge, Fatima
Several studies on the impact of climate warming have indicated that peat decomposition/mineralization will be enhanced. Most of these studies deal with the impact of experimental warming during summer when prevalent abiotic conditions are favorable to decomposition. Here, we investigated the effect of experimental air warming by open-top chambers (OTCs) on water-extractable organic matter (WEOM), microbial biomasses and enzymatic activities in two contrasted moisture sites named Bog and Fen sites, the latter considered as the wetter ones. While no or few changes in peat temperature and water content appeared under the overall effect of OTCs, we observed that air warming smoothed water content differences and led to a decrease in mean peat temperature at the warmed Bog sites. This thermal discrepancy between the two sites led to contrasting changes in microbial structure and activities: a rise in hydrolytic activity at the warmed Bog sites and a relative enhancement of bacterial biomass at the warmed Fen sites. These features were not associated with any change in WEOM properties namely carbon and sugar contents and aromaticity, suggesting that air warming did not trigger any shift in OM decomposition. Using various tools, we show that the use of single indicators of OM decomposition can lead to fallacious conclusions. Lastly, these patterns may change seasonally as a consequence of complex interactions between groundwater level and air warming, suggesting the need to improve our knowledge using a high time-resolution approach. (C) 2015 Elsevier B.V. All rights reserved.
- OPEN-TOP CHAMBERS
- EXTRACTABLE ORGANIC-MATTER
- COMMUNITY STRUCTURE
- CARBON ACCUMULATION
- PHENOL OXIDASE
[Delarue, Frederic; Gogo, Sebastien; Laggoun-Defarge, Fatima] Univ Orleans, ISTO, UMR 7327, F-45071 Orleans, France; [Delarue, Frederic; Gogo, Sebastien; Laggoun-Defarge, Fatima] CNRS, ISTO, UMR 7327, F-45071 Orleans, France; [Delarue, Frederic; Gogo, Sebastien; Laggoun-Defarge, Fatima] Bur Rech Geol & Minieres, ISTO, UMR 7327, F-45060 Orleans, France; [Buttler, Alexandre] Univ Franche Comte, UFR Sci & Tech, Lab Chronoenvironm, UMR CNRS 6249, F-25030 Besancon, France; [Buttler, Alexandre; Bragazza, Luca; Jassey, Vincent E. J.] Ecole Polytech Fed Lausanne, Sch Architecture Civil & Environm Engn ENAC, Lab Ecol Syst ECOS, CH-1015 Lausanne, Switzerland; [Buttler, Alexandre; Bragazza, Luca; Jassey, Vincent E. J.] WSL Swiss Fed Inst Forest Snow & Landscape Res, CH-1015 Lausanne, Switzerland; [Bragazza, Luca] Univ Ferrara, Dept Life Sci & Biotechnol, I-44121 Ferrara, Italy; [Grasset, Laurent] Univ Poitiers, CNRS, Lab Synth & React Subst Nat, UMR 6514, F-86022 Poitiers, France
Delarue, F (reprint author), Univ Paris 06, Univ Paris 04, Inst Mineral Phys Mat & Cosmochim, Museum Natl Hist Nat,UMR CNRS 7590,IRD UMR 206, 61 Rue Buffon, F-75005 Paris, France.
- Chrono-environnement, UMR6249
- Institut de Chimie des Milieux et des Matériaux de Poitiers (IC2MP), UMR7285
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR7590
- Institut des Sciences de la Terre d'Orléans (ISTO), UMR7327