Simulating landscape-scale effects of fuels treatments in the Sierra Nevada, California, USA

In many coniferous forests of the western United States, wildland fuel accumulation and projected climate conditions increase the likelihood that fires will become larger and more intense. Fuels treatments and prescribed fire are widely recommended, but there is uncertainty regarding their ability to reduce the severity of subsequent fires at a landscapescale.Ourobjectivewastoinvestigatetheinteractionsamonglandscape-scalefireregimes,fuelstreatmentsand fireweatherinthesouthernSierraNevada,California.Weusedaspatiallydynamicmodelofwildfire,successionandfuels management to simulate long-term (50 years), broad-scale (across 2.2 � 10 6 ha) effects of fuels treatments. We simulated thin-from-below treatments followed by prescribed fire under current weather conditions and under more severe weather. Simulated fuels management minimised the mortality of large, old trees, maintained total landscape plant biomass and extended fire rotation, but effects varied based on elevation, type of treatment and fire regime. The simulated area treated had a greater effect than treatment intensity, and effects were strongest where more fires intersected treatments and when simulatedweatherconditionswere moresevere. Inconclusion,fuelstreatmentsinconiferforestspotentiallyminimise the ecological effects of high-severity fire at a landscape scale provided that 8% of the landscape is treated every 5 years, especially if future fire weather conditions are more severe than those in recent years.