Coast Redwood Stand Composition, Structure, and Fuel Load Following Prescribed Fire in Big Basin Redwoods State Park

Abstract

With the prevalence of catastrophic wildfires increasing as a response to a century of widespread fire suppression, shifts in weather patterns, and other external factors, land managers throughout the United States have sought methods to increase the resiliency of landscapes to fire. With a host of adaptations to periodic disturbance, S. sempervirens has a competitive advantage over other species when fire is present. Utilizing sixty 10-meter diameter plots from sites previously burned in 1999, 2007, and 2011, and 60 unburned control sites, data was collected on forest stand composition and structure as well as understory species composition and dominance. Line intercept transects were used to assess downed woody fuel accumulation and receptive fuel bed depth. Permutational multivariate analysis of variance (PERMANOVA) results indicated statistically significant differences in stand composition, fuel load, and receptive fuel bed depth metrics. Kruskal Wallis and Spearman’s rank order correlation indicated increased density of juvenile and mature hardwood tree and shrub species, increased duff and litter depths, and increased load of coarse woody fuels in plots that had not experienced prescribed fire, while dominant overstory canopy species and understory non-woody plant species remained equivalent between treatments. These results suggest that prescribed fire can provide beneficial reductions in fuel load and juvenile tree and shrub species density without impacting overstory canopy or shade tolerant understory species.