Bioindication of troposher ic ozone by native vegetation: the potential of Viburnum lantana for large-scale surveys

Introduction Because its oxidative power, tropospheric ozone is considered, on a large scale, the most harmful pollutant to vegetation (Ashmore, 2005). The exceedances of critical levels set to protect vegetation are quite high and widespread, so that large parts of crops and forests in Europe are exposed to potentially harmful levels of ozone (EEA, 2009). The impact of ozone on vegetation is the result of multiple factors such as the concentration in the atmosphere, the stomatal uptake which depends on environmental and physiological factors and the detoxification potential of plants. The complexity of these factors and their interactions can make it difficult to establish a clear relationship between ozone and plant response under field conditions, and therefore to evaluate whether an impact is actually occurring. The use of plants as bioindicators may be a solution because ozone-specific symptom expression reflects and summarizes all processes that occur between ozone exposure and the actual response of the plant (Sawidis et al., 2011).