Description

Wildland fire is the dominant disturbance agent of the boreal forest of Alaska. Currently, about 80% of the population of Alaska resides in communities potentially at risk from wildland fire. The wildland fire threat to these settlements is increasing because of increased suburban construction in or near forested areas.  The primary objective of this research was to assess the effectiveness of maturing treatment projects in terms of previously defined risk reduction and fire behavior objectives in order to better understand the contribution of fuel treatments to the broader economics of wildfire management in Alaska.  Along with contributing to our knowledge on the ecological maturation of existing fuel treatments we also examined what influence publicly funded fuel treatments had on wildland fire suppression costs in Alaska, whether suppression resource ordering is affected by the presence of a fuel treatment, and what role fuel treatments play in encouraging homeowners in WUI locations to reduce wildfire risk on their property.  We found that fuel treatments in boreal black spruce induced surface layer species composition changes due to moss die-off without exposure of mineral soil, and to destabilization of soils and melting of frozen layers. Modeled fire behavior at the selected sites (BEHAVE 6.0) mostly indicate that shaded fuelbreaks still retain most benefits of reduced fire behavior potential (due to the reduction of canopy density and ladder fuels) for at least 14 years.  This finding fits with limited experiential evidence from prescribed and natural burning of fuelbreaks. Findings from a discrete choice experiment (DCE) suggest that responding homeowners were more willing to incur the additional costs associated with private wildfire risk mitigation when a thinned/shaded fuel treatment was present on nearby public lands.  This outcome does not hold in the presence of a cleared fuel break.  Drawing on treatment site field data collected as part of this effort a set of four wildland fire scenarios were modelled and presented to Alaskan wildland management professionals as part of an elicitation exercise designed to examine suppression resource ordering behavior. As expected suppression resource ordering depended on both current fire weather conditions and whether a fuel treatment was present.  Smaller initial attack packages were ordered when a fuel treatment was present and winds were 10 MPH and less in the scenario. Finally, State of Alaska wildfire suppression cost data was collected from a review of accounting records from over 200 fires and matched against fuels treatment data.  The analysis identifies 14 wildfires of greater than 50 acres where a fuel treatment was found within 5km of the final reported fire perimeter. No statistically significant relationship between fuel treatments and wildfire suppression costs was identified. We argue that the geographic scale of the state and low population densities have an unobserved impact in the likelihood of a fuel treatment being present near or adjacent to a fire.