Post-wildfire salvage logging effects on snag structure and dead woody fuel loadings

Abstract

Salvage logging is a controversial tool for post-wildfire management that removes fire-killed trees. We use a generalized randomized experimental design to fulfill two main objectives: (1) quantify the immediate (1-year post-harvest) effects of salvage logging on stand structure, fine and coarse woody fuel loadings; and (2) use pre- and post-empirical field data and the Fire and Fuels Extension to the Forest Vegetation Simulator (Reinhardt and Crookston 2003) to simulate post-wildfire dead woody fuel succession and snag dynamics. We compared the effects on woody fuel loadings of two salvage logging prescriptions: (1) seed tree harvest, thin to 3.4 m2·ha−1; and (2) full salvage of all merchantable timber, relative to unlogged controls. There was substantial block-level variability in the implementation of the treatments and in their immediate effects on fine fuel loading, complicating comparison of the two prescriptions. Overall, salvage logging did reduce snag basal area and, relative to unlogged controls, significantly increased measured fine woody fuel loading (10 and 100 h). Simulated snag fall was rapid, with a mean predicted snag basal area loss of 61% within 10 years. Future long-term monitoring of permanent field plots will supplement model predictions and provide valuable data to inform post-wildfire management decisions.