| Surface fires were simulated using the FARSITE fire spread simulation model for the Chequamegon National Forest (CNF) in northern Wisconsin, USA, to examine hypothetical fuel structures in various landscape scenarios. The objective was to determine if there were significant differences in mean burned area between scenarios when landscape structure was changed. Simulated harvesting and various levels of fuel loading in the area of edge influence (AEI) were used to create different landscape scenarios. Area of multiple edge influence (AMEI) was included to provide scenarios with three levels of edge fuel, to the fire simulations. AEI and AMEI were delineated using a geographic information system to create the edge structure. Daily differences in fire front vector direction and fuel loading among landscapes were also determined from modeled results. Rain and wind input scenarios were added to examine their effects on fire spread as well. Depth of edge influence (DEI) was assigned as 30 m or 60 m to give edges a width dimension. I found significant differences in mean burned area, using ANOVA tests, among landscape scenarios after fire simulation. Different landscape structure was able to increase or decrease the rate of fire spread. By ranking landscape fire size projections, this research provides lessons for forest managers on how to influencing fire spread by changing landscape characteristics, (i.e., fuel patch size, shape or loading). Fuels in AEI contributed to changes in the fire front vector direction and fuel loading, which influenced fire movement. Low and medium fuel loading edge scenarios slowed fire spread, which changed the direction of the fire front. In high fuel loading edge scenarios, edges acted as corridors for fire spread and dominated the fire front vector fuel loading overriding the role of the dominant ecosystem fuel in that location. I concluded that understanding and managing landscape level fuels, especially in edge, was important in controlling fire spread. Simulating landscapes with AEI led to more precise fire size projections. Forest managers can use these lessons, along with specific fuel treatments, to change the overall predisposition of the landscape in regards to its fire spread potential. |
