Comment on Hanson, C.T. Cumulative Severity of Thinned and Unthinned Forests in a Large California Wildfire. Land 2022, 11, 373

Hanson (2022) evaluated thinning as a management tool to reduce wildfire tree mortality using thinning history and fire mortality data from the Goosenest Adaptive Management Area (GAMA) in California. The combination of on-the-ground measurements of thinning tree removal with remote sensing fire mortality data is questionable. Using his data, fire mortality in thinned stands was calculated and found to be less than mortality in unthinned (control) stands. Fire mortality in experimental plots does not properly represent the full benefits of density reduction because lower density provides a risk reduction that increases as more area is treated, due to the nature of fire spread. Thus, the conclusion that thinning is not beneficial is not supported by Hanson’s study and does not consider the importance of individual tree mortality vs. catastrophic forest loss and associated reductions in ecosystem services and loss of human infrastructure.