1 on very acid substrata, such as lignum and conifer bark
2 on acid substrata, such on non-eutrophicated bark of Quercus
3 on subacid to subneutral substrata (e.g. on bark of Sambucus)
4 on slightly basic substrata, such as dust-covered bark
5 on basic substrata, e.g. pure limestone

1 in very shaded situations, e.g. deep gorges, closed evergreen forests
2 in shaded situations, such as on the northern side of boles in close-canopied deciduous forests
3 in sites with plenty of diffuse light but scarce direct solar irradiation, such as in rather open-canopied deciduous woodlands
4 in sun-exposed sites, but avoiding extreme solar irradiation
5 in sites with very high direct solar irradiation, e.g. on the southern side of isolated boles

1 hygrophytic, in sites with a very high frequency of fog
2 rather hygrophytic, intermediate between 1 and 2
3 mesophytic
4 xerophytic, but absent from extremely arid stands
5 very xerophytic

1 no eutrophication
2 very weak eutrophication
3 weak eutrophication
4 rather high eutrophication
5 very high eutrophication

This value points to the tendency of a lichen to occur in areas with different degrees of human disturbance. It is expressed on 4 classes, as follows:
0 species which exclusively occur on old trees in ancient, undisturbed forests. Contrary to the other values, this one has been assigned to epiphytic species only, since it is useful to point out indicators of long ecological continuity of forests.
1 species occurring in natural or semi-natural habitats
2 species occurring in moderately disturbed areas (agricultural areas, small settlements etc.)
3 species occurring in heavily disturbed areas, incl. large towns

1 eu-Mediterranean belt (potential vegetation: evergreen Quercus ilex forest)
2 submediterranean belt (deciduous Quercus-Carpinus forests)
3 montane belt (Fagus forests, marking treeline in the Apennines)
4 Oroboreal belt of the Alps (natural Picea abies, and Larix-Pinus cembra stands)
5 above treeline (both Alpine and oromediterranean)

1Extremely rare
2Very rare
3Rare
4Rather rare
5Rather common
6Common
7Very common
8Extremely common