Riverine particulate C and N generated at the permafrost thaw front: case study of western Siberian rivers across a 1700 km latitudinal transect

摘要: Abstract. In contrast to numerous studies on the dynamics of dissolved ( µ m) elements in permafrost-affected high-latitude rivers, very little is known behavior river suspended >0.45 m) matter (RSM) these regions. order test effect climate, permafrost and physio-geographical landscape parameters (bogs, forest and lake coverage watershed) RSM particulate C, N P concentrations water, we sampled 33 small medium-sized rivers (10–100 000 km 2 along a 1700 km N–S transect including both permafrost-free zones Western Siberian Lowland (WSL). The concentrations C decreased with the increase watershed size, illustrating (i) the importance of organic debris which drain peatlands (ii) the role of mineral matter from bank abrasion larger rivers. presence lakes in the increased but P RSM. The C:N ratio reflected source deep soil horizon rather than surface soil horizon, similar that other Arctic This suggests the export peat mineral particles through suprapermafrost flow occurring at base active layer. There was maximum C and export fluxes at beginning permafrost appearance, sporadic discontinuous zone (62–64 ∘  N). This presumably organic mobilization newly thawed organic horizons soils latitudinal thawing front. The results suggest northward shift permafrost boundaries an increase layer thickness may export by WSL Ocean by factor 2, while may remain unchanged. contrast, within long-term climate warming scenario, the disappearance north, drainage and transformation bogs decrease RSM by 3 times.