Linking pattern and process is one of the major challenges confronting basic and applied ecology. This is largely a scaling issue, of interfacing mechanistic approaches from the molecular through population levels. Characterizing interfaces, feedback structures, and underlying thresholds helps us understand ecological interactions. We use bark-beetle-conifer microbial interactions as our primary model because of their complex associations with host plants, ability to generate positive feedback through flexible host selection and cooperative pheromone behaviors, important symbiotic associations, and eruptive population dynamics. We also apply multiple-scale approaches to issues such as risk assessment & deployment strategies of genetically modified trees. Current investigations include:

• Relative roles of internal positive feedback, external drivers, and dispersal in surpassing eruptive thresholds
• Disturbance interactions, such as fire and bark beetles
• Range expansions in naive hosts and habitats driven by climate change
• Role of constitutive & induced tree defense chemistry in restricting insect colonization success
• Role of microorganisms and flexible host selection behavior in colonization success
• Role of microorganisms, tree chemistry and pheromones in natural enemy behavior & impact

Collaborators: Allan Carroll (Can FS), Brian Aukema (Univ MN), Monica Turner (UW-Zoo), Joerg Bohlman (UBC), Kier Klepzig (USFS), Phil Townsend (UW-FWE), Nadir Erbilgin (Univ Alberta), Barbara Bentz (USFS)

Selected Publications and Presentations