Presented by: Emily C. Geyman
Affiliation: TBA
Location: 3853 Slichter Hall
Abstract: The vast accumulation of carbon in Arctic soils—an estimated 1,700 Pg—has been referred to as a carbon bomb, a sleeping giant, and Pandora’s freezer. These terms all refer to the so-called ‘permafrost–carbon feedback,’ the cascading cycle in which warming temperatures destabilize permafrost soils, liberating large quantities of carbon to the atmosphere and driving further warming. But predicting whether Arctic landscapes will be a net source or sink of carbon requires tracking the transport and fate of the mobilized soil carbon and quantifying the strength of counteracting processes such as enhanced primary productivity of vegetation. I’ll show how the deposits of meandering rivers provide natural landscape-scale experiments that juxtapose frozen and thawed (permafrost and non-permafrost) terrain in the same environment, allowing us to track the changes to soil carbon and biomass reservoirs over timescales of years to millennia. These observations suggest that permafrost thaw may cause some Arctic landscapes to become a net carbon sink rather than a carbon source.