Collaborative Research: Wildfire and Mountain Pine Beetle Outbreaks in Subalpine Forests: Cross-Scale Interactions Under Varying Climate

Clark University, Worcester MA

Investigators

Abstract

Large outbreaks of native bark beetles (Dendroctonus spp.) are occurring throughout coniferous forests of western North America, from western Alaska to the U.S. Southwest and are believed to be related to climatic warming. In Colorado more than 270,000 ha of lodgepole pine forests have recently been infested by mountain pine beetle (MPB) (D. ponderosae), which has led to widespread public concern about increased fire hazard following beetle kill. This research addresses four key questions about interactions of wildfire, outbreaks and climate and their potential cross-scale feedbacks in subalpine forests in northern Colorado. 1) How does climatic variation at seasonal, annual, and multi-decadal time scales affect the initiation and spread of MPB outbreaks across complex landscapes? 2) How does the landscape heterogeneity created by prior disturbance by fire affect the risk and/or spread of subsequent disturbance by MPB outbreak across complex landscapes? 3) How does the landscape heterogeneity created by prior disturbance by MPB affect the fuel hazard and risk of wildfire across complex landscapes? 4) How do context-specific contingencies between climate and the landscape affect the initiation and spread of wildfire and MPB outbreaks? This project will examine possible feedbacks between wildfires and bark beetle outbreaks across different spatial scales and under varying climatic conditions. The research and associated outreach will improve understanding of the influence of beetle kill on future fire risk, which is of broad current interest to resource managers, the fire mitigation community and the public living in the bark-beetle affected areas.