Evaluating ecological resilience across wildfire suppression levels under climate and fuel treatment scenarios using landscape simulation modelling

Continued suppression of wildfires may allow more biomass to accumulate to foster even more intense fires. Enlightened fire management involves explicitly determining concurrent levels of suppression, wildland fire use (allowing some fires to burn) and fuel treatments to manage landscapes for ecological resilience. This study used the mechanistic landscape model FireBGCv2 to simulate ecological dynamics on three landscapes in the US northern Rocky Mountains to determine responses of seven management-oriented variables over a gradient of 10 fire suppression levels under two climate and four fuel treatment scenarios. We used a historical range and variation (HRV) time series of the seven variables individually and merged together as a Principal Components factor (PC1) to define the envelope that represents ecological resiliency and compared all simulations with the HRV base case. We found that under today's climates, using the PC1 factor, ecological resilience was maintained while suppressing 30-90% of wildfires depending on the landscape. We also found fuel treatments might allow higher suppression levels to occur and still maintain resilience. Other findings indicate that each landscape must be individually evaluated to determine the right mix of wildfires, wildland fire use and fuel treatments depending on the response variables used to evaluate resilience.