Tropospheric ozone is considered as the most significant phytotoxic pollutant in the atmosphere and, globally, there is evidence that the background ozone concentrations are further increasing. While it has been shown that ozone concentrations have significant effects on crop yields, forest growth and species composition, the impacts of ozone on biodiversity are largely unknown. We study the impacts on biodiversity of terrestrial ecosystems (e.g. agro-ecosystems, semi-natural ecosystems) by means of experiments, database reviews and modelling approaches. Our aim is to improve and further develop methods to assess the risks of ozone for vegetation and biodiversity in Germany.