The Effect of Permafrost Thaw on Methane Emissions in a Western Alaska Peatland Chronosequence

摘要

Our results provide a 1000 year chronology of the relationship between CH_4 fluxes and seasonal temperature patterns as a function of time since thaw. Thaw of ice-rich peat leads to saturation, and lateral thaw propagation with time leads to warming of saturated soils and increasing CH_4 emissions. After ～1000 y, plant community succession stabilizes thaw boundaries through drying and cooling of thaw features, reducing CH_4 emissions. This long-term, slow-pulse response may occur with increasing areal frequency in vulnerable lowland locations as air temperatures continue to rise, potentially leading to dramatically increased CH_4 production from lowland settings in the future.