A review of the social and ecological impacts of mountain pine beetle (Dendroctonus ponderosae) during and after an outbreak on forests in North America

Mountain pine beetle (Dendroctonus ponderosae; MPB) is a species of bark beetle historically located in western North America. It colonizes various pine tree species to feed and produce offspring, typically resulting in tree death. Under favourable conditions, populations can undergo eruptive outbreaks and induce extensive forest mortality. The last epidemic in North America spanned 1995 to 2015 and was magnitudes greater than any epidemic in recorded history. Despite its broad geographic scale, there has yet to be a synthesis of how MPB-affected ecosystems recover. This review integrates research from social, biological, and forest ecological literatures to provide an assessment of the impact of MPB epidemics on forest ecosystems and human communities across short (1-2 years) and long-time spans (5-10 years). We found that forest recovery can take many paths, but recovery is highly dependent on the severity of the epidemic and management within the affected area post-outbreak. We outline critical factors for forest managers in anticipating and mitigating the effects of insect disturbances for forest ecosystems and the communities which depend on them.