Extended abstract for: Summer Temperature Extremes as a Driver in MPB outbreaks

Mountain pine beetle (MPB) epidemics are emerging as a significant disturbance factor in western forests from British Columbia to the Southwest. Warmer winters attributed to climate change have been implicated in the massive MPB outbreaks in British Columbia and Alberta Canada. In more southerly environments, low winter temperatures have not historically played a role in controlling MPB epidemics. Research on the MPB epidemic in eastern Washington indicates that increasing summer temperature and its effect on vapor pressure deficit is the primary driver of host susceptibility to MPB. Linking climate variability to site, stand, and tree characteristics is necessary in order to develop a blueprint for management action that can reduce the incidence of widespread MPB attacks. While increasing insect activity under warmer climate conditions is certainly implicated in the increase in MPB attack levels in the recent past, actions that address increasing host susceptibility are necessary to control the magnitude of this disturbance vector under a changing climatic regime.