Decades of fire exclusion have led to hazardous fuel accumulations and the
deterioration of fire-dependent ecosystems, particularly in the American We
st. Managers are striving to return the ecological role of fire to many eco
systems and would benefit from a much better understanding of how forest st
ructure and composition might change if fires were reintroduced. We used a
forest gap model, developed for forests in the Sierra Nevada, California, U
SA, that integrates climate, fire, and forest dynamics to investigate fores
t response to changes in the fire regime. The model simulates a spatially h
eterogeneous fuel bed that is responsive to changes in forest condition, ma
king it well suited for examining alternative management approaches for res
toring Sierra Nevada forests after a century of fire exclusion. Presuppress
ion forest basal area, species composition, and spatial autocorrelation str
ucture were restored quickly, if simulated disturbances that caused substan
tial tree mortality were reintroduced. Simulations of harvest induced the h
ighest levels of mortality and, thus, most effectively restored forest stru
cture and composition. However, prescribed fires were just as effective in
restoring forest structure and composition if they were sufficiently severe
.