I have been monitoring conifer mortality in Mendocino, Lake, Napa, and Sonoma Counties for the past year. Based on my observations and review of aerial detection surveys conducted by CAL FIRE Forest Health Specialists, the region is currently experiencing significant conifer mortality due to an outbreak of several native bark beetle species. Primary conifers impacted (and associated bark beetles) include ponderosa pine (western pine beetle), Douglas-fir (flatheaded fir borer and Douglas-fir engraver), Grey pine and knobcone pine (Ips species).

These outbreaks likely originated in areas...