Abstract:

Peatlands are the most efficient terrestrial ecosystems in storing carbon，which contain approximately one third of the world’s soil carbon pool and play an important role in global carbon cycling. During the last two decades, increases in dissolved organic carbon (DOC) concentrations have been observed in freshwaters across large areas of Northern Hemisphere. It is generally considered to be related to large scale DOC releasing from Northern Peatlands. Several hypotheses have been put forward as potential driving mechanisms for the increase in DOC, including (1) changes in  temperature; (2) elevated CO2 concentrations; (3) changes in Hydrological processes; (4) Decrease in sulphur deposition. However, none of the proposed hypotheses is completely convincing. After reviewing previous studies, we proposed that the combining forces of temperature and hydrological processes under global change possibly  are the main dominant drivers of DOC change, though multiple mechanisms for rising DOC exist. 

Key words:  driving mechanism, dissolved organic carbon, peatland, global change