Grant: Discovery Launch Supplement

Introduction: Tree-killing bark beetle outbreaks increasingly threaten forests. To ensure sustainable forest services, we must understand the drivers of outbreaks and their lasting impacts. Fungi can play key roles in forest disturbances by impacting beetle development, tree health, and post-disturbance regeneration. My research program explores the activities of fungal communities associated with beetles and present in forest soils, aiming to determine their function in outbreak processes for beetle species of concern. Program Overview: My interdisciplinary program studies fungal community functions throughout the disturbance process for spruce beetle (SB) and western balsam bark beetle (WBBB) outbreaks in western Canada. To do this, we focus on the nutritional and semiochemical qualities of fungal communities that promote beetle population growth. Furthermore, we explore how fungi help kill beetle-attacked trees and how soil fungi affect successful forest regeneration after outbreaks. Objective 1: Nutritional and Semiochemical Support Bark beetle-vectored fungi supply essential fatty acids for larval growth, which then use volatile cues to find host trees. The lipid content of SB and WBBB fungi and the impacts of their emitted volatiles on beetles and fungi are unknown. We will characterize beetle fungal communities and determine their nutritional content and volatile-mediated effects. Objective 2: Reciprocal Fungus-Tree Interactions Some beetle-vectored fungi infect trees during beetle attack, which stimulates tree defenses that may deplete carbon reserves over time. How this process is differentially affected by fungal communities and how such communities are impacted by tree defense chemicals is unknown. My program will investigate how SB and WBBB fungal communities affect tree defensive metabolites and their impact on fungi. Objective 3: Benefits to Forest Regeneration disturbances alter the communities of sensitive soil fungi that support healthy and vigorous forest regeneration. Whether such altered communities can support forest regeneration in SB- and WBBB-killed stands is unknown. My program will determine how the beetle outbreaks change soil fungal communities and their benefits to seedling productivity and health. Impact: My research program will clarify the role of fungal communities in beetle outbreaks, guiding comprehensive management strategies to ensure sustainable forest services. The outcomes will inform effective beetle control methods, uncover tree resistance markers, and set ecosystem restoration goals. This work will help manage beetle outbreaks in Canada and equips HQP with vital skills for addressing future forest health challenges. HQP and EDI: My five-year training plan involves 7 undergraduates, 3 MSc, and 2 PhD students. EDI is a keystone in my plan as diverse voices strengthen science. My program trains students in an interdisciplinary blend of fungal ecology, forest health, and analytical chemistry.