Forests play a role in air quality by supplying the atmosphere with volatile organic compounds (VOCs), precursors to ozone and aerosols. Different tree types emit different VOCs, each with different capacity to form ozone and aerosols. Therefore, shifts in forest composition may impact ozone and aerosol yields. Climate change is one of the expected drivers of forest change. In particular, the current range boundaries of a variety of species are expected to shift northward.