Fire in Northern Alaska: Effect of a Changing Disturbance Regime on a Regional Macrosystem

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Increased temperatures in Northern Alaska over the past 50 years have been accompanied by an increase in the frequency of wildfires, with over half of the fire activity on the North Slope in the past 60 years occurring since 2000. The effects of fire on carbon and energy balances in this region are poorly understood, as the fires have occurred in remote regions, been small in size, and are relatively infrequent. Arctic ecosystems store twice the amount of carbon currently in the atmosphere and affect the local and regional climate by exchanging carbon with the atmosphere and through their impacts on the reflectivity of the tundra surface and heat penetration into permafrost soils. Fires have potential to alter the balances by releasing carbon into the atmosphere through combustion, reducing carbon sequestration through vegetation and soil changes, and influencing climate by darkening the surface and allowing more solar energy to be absorbed. The goal of this research is to develop a better understanding of the short-term (daily to annual) and long-term (decadal to centennial) effects of fire on Arctic tundra. The goal will be met by combining field measurements made at burned sites of different age on the North Slope and Seward Peninsula of Alaska, along with recent and historical satellite and aircraft remotely sensed imagery, into predictive models of how fires influence carbon and energy cycling over time across the Arctic.The models developed in this project can be used to inform future management decisions by predicting the impacts of future changes in the frequency of fires on ecosystem services in the Arctic. It will reveal processes and interactions that are relevant not only to the global human population as related to climate change, but also to the local Native American populations that depend on the North Slope landscape to sustain their subsistence lifestyles. Several postdoctoral and undergraduate researchers will be trained and contributions made to outreach programs currently run by the Arctic Long-Term Ecological Research project and the Marine Biological Laboratory. These contributions include internet-based distribution of data collected and models created, as well as public lectures and classroom exercises in local Native Alaskan communities.