Streams are sensitive sentinels for environmental change by their integration of processes in terrestrial and aquatic systems. We currently observe exceptionally high concentrations of invisible carbon (C), as stream CO2 and uncolored dissolved organic C (DOC), in tundra headwater streams. We suggest that current climate change mobilizes the stored C in upland tundra soils causing a substantial increase in headwater stream C emissions and water-borne C losses. This is a hitherto unknown effect of a changing tundra landscape that most likely will have a large positive feedback on the global climate warming because of the large quantities of C that is stored in tundra soils. The aim of this study is therefore to 1) disentangle the causes and consequences of this stream C for the tundra C balance, 2) propose methods for how we better can follow these changes in the arctic landscape and 3) establish a more permanent longterm monitoring program for headwater streams in the Swedish tundra.

Abisko, Sweden
Abisko, Sweden