Correction to: Recalibration and validation of the Swiss lichen bioindication methods for air quality assessment.

The correct fig. 2 is presented in this paper.

Recalibration and validation of the Swiss lichen bioindication methods for air quality assessment.

The aim of this study was to recalibrate the Swiss lichen bioindication methods, developed and calibrated with air pollution data 30 years ago. Since then, levels of air pollution have considerably decreased, and the mix of pollutants has changed due to successful emission control in Switzerland and neighboring countries. In particular, there has been a change from a sulfur- and acid-dominated to a more nitrogen-dominated pollution mix of NH/NO and ozone, resulting in increased pH levels.