A Conceptual and Mechanistic Approach to Understanding Interactions Among Multiple Disturbance Agents: Compound Effects of Fire on Resource Availabilty to Bark Beetles

The objective of our project has been to determine the effects of fire on bark beetle populations in the Greater Yellowstone Ecosystem. Our general hypothesis has been that fire damaged trees provide refugia for mountain pine beetles (D. ponderosae) that allow populations to persist during non-outbreak periods. Our work combines field testing of bark beetle populations within a range of forests from burned to unburned, as well as spatial analyses (remote sensing) to determine whether the forest more proximal to fires have greater incidences of beetle mass attack. New efforts have focused on determining whether lodgepole pine (P. contorta) and whitebark pine (P. albicaulis) have differing chemical defensive capacities to beetle attack.