Changes in the Forest Fire Regime in Interior Alaska: An Example of Human-Climate Interactions
Henry Huntington, Hunting Consulting, Eagle River, Alaska, USA,
Scott Rupp, University of Alaska Fairbanks
Mark Olson, University of Alaska Fairbanks
David Natcher, Memorial University of Newfoundland
F. Stuart Chapin, University of Alaska Fairbanks

Forest fires are a major feature of the boreal ecosystem in Interior Alaska. The fire regime—the frequency of fires, the patterns of burning, and other characteristics of forest fire dynamics—has a major influence on landscape-scale vegetation patterns, ecosystem productivity, and human activities such as hunting, trapping, and fire fighting. Evidence from field studies indicates differences in fire regime in areas with different histories of human occupation. Analyzing these differences with a fire system model suggests that the fire regime is moderately sensitive to human activities. Field studies and modeling are also consistent in identifying climate as a major influence on fire regime. Using a hypothetical landscape, we explore scenarios for future human activity and climate change, comparing the effects of human activities alone, climate alone, and the two in combination. We conclude that the interactions of human activities and climate both produce the greatest effects and are the most likely scenario for the coming century. Our findings suggest that the Arctic is an indicator not only of climate change, but of the mechanisms and significance of interactions between human activity and climate.

ALFRESCO modeling runs:

  1. Ruby-Nowitna comparisons to establish that humans can have a significant impact at the landscape level
  2. Hypothetical landscape with steady climate & human activity, 2000-2100
  3. Hypothetical landscape with various levels of suppression/ignition (e.g., through land disposal (-> cabins -> more fire suppression; also -> people -> more fire starts) or overall fire policy), 2000-2100
  4. Hypothetical landscape with climate change, 2000-2100
  5. Hypothetical landscape with various levels of suppression/ignition plus changing climate, 2000-2100