VDI 3957 Blatt 21:2017-02

For decades lichens have been used for bioindication of the impact of air pollution as means of active and passive biomonitoring. Owing to their pronounced sensitivity to air pollution, lichens exhibit advantages with respect to biomonitoring compared to vascular plants and most animal species. In the case of a reduction of the number of lichen types in the area under investigation caused by massive air pollution or by a lack of suitable substrate (trees), the 'standardised exposure of lichens' has proved to be successful in the practice of biomonitoring of air pollution exposure with lichens. This method facilitates the temporal and spatial resolution of adverse effects of air pollution within the exposure period. Thereby the method aims at the determination of the current effects of air pollution. The foliose lichen Hypogymnia physodes has proven to be successful in exposures and is therefore used for the determination and assessment of phytotoxic effects of air pollution according to this standard.