XVI International Botanical Congess

Real and simulated herbivory of conifer needles triggered localized monoterpene synthesis, supporting the role monoterpenes play in conifer defense. Herbivory also eliminated tissue diffusive resistance to emissions and triggered an initial 60 fold increase in the monoterpene emission rate which decreased over time. A zero-dimensional photochemical model explored the potential impact of 10 and 25% tissue damage in a coniferous forest on tropospheric chemistry. Simulations suggest even 10% damage is enough to suppress OH concentrations and increase production of ozone and organic nitrates. The predicted magnitude of the perturbations increased linearly with the extent of damage and was dependent on local mixing ratios of nitrogen oxides and isoprene.