Hydrological carbon transport in the Abiskojokka catchment area : The relationship between soil organic carbon content and dissolved organic carbon concentrations in stream water

Soils in permafrost regions hold substantial amounts of carbon, much of which has accumulated due to processes that are related to cold temperatures. A warming climate will alter the dynamics governing the fluxes of carbon within a system and consequently the pools of carbon therein. Of particular concern is whether previously stored carbon will be released to the atmosphere contributing to the pool of greenhouse gases and creating a feedback effect. At the moment the International Panel of Climate Change (IPCC) does not include carbon dynamics of the Arctic in their forecast models due to a lack of adequate scientific understanding in the area. Understanding the controls which govern the fluxes of carbon between the land, the atmosphere and the aquatic systems is important in evaluating the transient state of the carbon cycle. This study investigates the potential relationship between terrestrial soil organic carbon (SOC) pools and the dissolved organic carbon (DOC) concentrations in streams observed at the beginning of August 2012 in the Abiskojokka catchment in the sub-arctic region of northern Sweden. The results show that soil organic carbon pools could tentatively explain between 24 % and 44 % of the variation in DOC concentrations in streams. This is only a fraction of the variation explained compared to regions where peatlands are the single most important indicator of DOC concentrations. In the absence of peatland, which covers less than 2 % of the Abiskojokka catchment area, heath vegetation and the associated soil forming processes were shown to be an important indicator of stream water DOC concentrations