Interannual to decadal drought and wildfire in the western United States

Twentieth‐century wildfire suppression and land management policies have promoted biomass accumulations in some ecosystems in the western United States where wildfire is a natural and necessary element. These changes have fueled large, stand‐replacing crown fires in southwestern ponderosa pine forests, where they were rare under natural fire regimes [ Allen et al. , 2002]. Current policy contemplates massive ecosystem restoration involving prescribed fires and mechanical fuel reductions on millions of hectares and the subsequent re‐introduction of pre‐suppression fire regimes [ USDA and USDI , 2002]. Success critically depends on understanding past and present fire regimes. The current western drought and the potential for climatic change to increase the frequency and magnitude of the region's droughts [ Smith et al. , 2001] further emphasize the need to understand short‐ and long‐term climate‐fire relations.