My main research interest is chemical ecology of boreal trees. I have worked extensively on how environmental changes, including elevated levels of temperature, CO2, ultraviolet- and ionizing radiation, light intensity, and nitrogen, affect tree growth and the levels of phenolic defenses. In addition to trees, I have also studied various species of higher plants and lichens from both forests and arctic-alpine ecosystems. I am also interested in how plant- and fungi derived compounds contribute to the carbon storage in soils, and how trees influence the belowground microbiome. I have also been involved in projects looking at the effects of light quality and temperature on tree Phenology.