Growing peatlands are an important long-term carbon (C) sink and thus play a key role in the global C cycle. Vast surfaces of northern peatlands have been mined for peat and are currently abandoned. In these surfaces, secondary vegetation succession takes place, leading to Sphagnum- dominated communities. It is unclear if these regenerating cutover bogs accumulate C, and in particular if the successful re-establishment of Sphagnum mosses suffices to infer that the C sequestration function has been restored. We studied the vegetation and C dynamics in a cutover bog in the Swiss Jura Mountains at three stages of regeneration (A: 29 years of regeneration, B: 42 years, and C: 51 years - ages derived from tree rings counts) and estimated the Net Ecosystem Exchange