Tundra fire and vegetation dynamics: Simulating the effects of climate change on fire regimes in arctic ecosystems

Poster presented by Amy Breen and co-authors at the 2013 American Geophysical Union Fall Meeting.

Abstract: In Arctic Alaska, changes in climate are expected to increase the extent and frequency of wildres yet the implication and consequences are poorly understood. Predicting landscape flammability and vegetation dynamics in response to climate change is a challenge because of the complex interactions between climate, disturbance and recruitment across the landscape. We used a spatially explicit model, Alaska Frame-Based Ecosystem Code (ALFRESCO), to simulate the effect of climate change on regimes and tundra successional trajectories, specifically the conversion of tundra to shrubland and forest. Changes in re regime and vegetation response were simulated by ALFRESCO driven by downscaled General Circulation Model (GCM) outputs from the CCCMA-CGCM3.1 and MPI ECHAM5 models under the A1B emissions scenario at 1 x 1 km resolution for Arctic Alaska. In the simulations warming caused an increase in the total area burned per decade, which led to to conversion of graminoid tundra to shrub tundra and modest expansion of forest into previously treeless tundra through the 21st century. We present these results and discuss the potential impacts of a changing tundra re regime on terrestrial ecosystems in Arctic Alaska.