Lichen communities in the cathedral of Leon

In the cathedral of León, 36.36% of the sampled surface is covered by up to 39 lichen taxa. Two different communities were found, either on carbonate rocks or on highly nitrified environments. The first is composed of species with crustaceous biotypes, mainly belonging to the generaCaloplaca, Aspicilia andRinodina. The other community is composed of species with foliaceous or lobed crustaceous biotypes of the generaPhyscia, Physconia andPhaeophysica, this latter community being the one producing the higher degree of physical biodeterioration, because of its higher rate of foliaceous species. The species distribution depends directly on nitrophytism, hygrophytism, photophytism and pH index, and to a lesser extent on the variation of the inclination angle, orientation and substratum type.