Figure 4.

Box and whisker plots of lichen sensitivity ratings by functional group. Boxes enclose 25–75% quantiles, whiskers mark upper and lower outliers (1.5 times the interquartile range). The horizontal line indicates the overall median for the pollutant. Very few cyanolichens or pendant forage lichens were tolerant to S or N (sensitivity rating > 8 kg ha⁻¹ y⁻¹). Medium to large matrix lichens exhibited the broadest range of sensitivities. Abbreviations as in Figure 3.