Effects of short-term ecosystem experimental warming on water-extractable organic matter in an ombrotrophic Sphagnum peatland (Le Forbonnet, France)

► Impact of experimental warming (using OTCs) on the dynamics of water-extractable organic matter (WEOM) was examined. ► In Le Forbonnet peatland, two sites (DRY and WET) were selected as a function of moisture conditions. ► At DRY site, the impact of OTCs was weak with respect to WEOM dynamics. ► At WET site, air warming induced greater evapotranspiration and OM decomposition at the peat surface. ► We concluded that the spatial variability of moisture is key for understanding the impact of warming on peatland functioning.