Cross-section of an Engelmann Spruce with Fire Scars

Figure 2.  A partial cross-section from a live Engelmann spruce with three fire scars (1801, 1847, and 1880), indicating repeated, low-severity, moderate frequency surface fire in a wet mixed-conifer forest. Human land use - intensive grazing followed by active fire suppression - has excluded fire from this site for the last 131 years, which is almost three times the historical maximum interval (46 years). (From Figure 4 in Margolis and Malevich, 2016)