Assessing Landscape Vulnerability to Permafrost Thaw, Wildfires, and Hydrologic Changes on Boreal Alaska

Climate warming, altered precipitation and fire regimes are driving rapid permafrost degradation, especially in the discontinuous permafrost zone of boreal Alaska. Abrupt thaw of ice-rich permafrost can trigger ground subsidence and thermokarst disturbance resulting in landscape transition with dramatic consequences for infrastructure stability, wildlife habitat, local hydrology and the regional carbon budget. With the goal to assess historical and projected landscape vulnerability to climate change and altered disturbance regimes in the permafrost region, we developed a state and transition model that simulates land cover trajectories driven by thermokarst, wildfire, altered hydrology, climate change and succession. We synthesized field observation and remote sensing data documenting 60 years of land cover change in Interior Alaska, to inform this spatially and temporally explicit model and assess land cover dynamic from 2000 to 2050 at a 30 m resolution, and its impact on wetland distribution and wildlife habitat. Preliminary results of these simulations suggest that wildfire, paludification and abrupt permafrost thaw are the main drivers of land cover change in Interior Alaska, affecting a total of 32%, 16% and 15% of the landscape respectively between 2000 and 2050.