In situ and laboratory non-additive litter mixture effect on C dynamics of Sphagnum rubellum and Molinia caerulea litters

Purpose The accumulation of carbon in peatlands originates from the slow rate of Sphagnum litter decomposition. Vegetation shifts can alter the Sphagnum decomposition rate through a litter mixture effect. This is rarely studied in peatlands. In a site colonised by vascular plants, we examined the effect of mixing litters of Sphagnum species with those of Molinia caerulea and Betula spp. on litter carbon (C) dynamics. We tested that water content and pH may explain the potential non-additive litter mixing effect.