The effects of elevated CO2 and O3 on paper birch resistance to bronze birch borer

Changes in atmospheric composition affect host plant quality, which can influence herbivore population dynamics. We investigated the effects of ambient and elevated carbon dioxide (CO₂) and ozone (O₃), alone and in combination, on paper birch (Betula papyrifera) resistance to bronze birch borer (Agrilus anxius) at the Aspen Free Air CO₂ Enrichment (FACE) facility in Rhinelander, WI, as well as phloem defenses hypothesized to be important mechanisms of resistance of angiosperm trees to wood-borers. Specifically, we will report effects of atmospheric composition on degree of bronze birch borer colonization, rate of wound-periderm formation in the phloem, as well as induced and constitutive secondary chemistry.