Giordani, P., Calatayud, V., Stofer, S., Seidling, W., Granke, O., & Fischer, R. (2014). Detecting the nitrogen critical loads on European forests by means of epiphytic lichens. A signal-to-noise evaluation. Forest Ecology and Management, 311, 29-40. https://doi.org/10.1016/j.foreco.2013.05.048