World distribution: The species has a Mediterranean-Atlantic distribution in Europe (Jørgensen 1978). Outside Europe it is known only from Tunisia. In the Mediterranean region it normally grows at altitudes between 400 and 800 m, but it has been found up to 1200 m in Spain. In northwest Europe it is a lowland species hardly reaching altitudes higher than 300-400 m. The species is strictly western in Fennoscandia. It has been found in two sites on the west coast of Sweden, from which it is now extinct (Aronsson et al. 1995). The nearest known extant occurrences outside Norway are in western Scotland
Ecology: Results. The substrate (indicated in 28 localities) included rock (10) and trees (18). When saxicolous, it occurred on naked or moss covered rock, including vertical rock (4), schistose overhang (2), and moss covered boulder (1). On one site the rock was inundated. When corticolous it occurred on Quercus spp. (7), Fraxinus excelsior (5), Populus tremula (4), Tilia cordata (2), and Alnus incana (1), Corylus avellana (1), and Sorbus aucuparia (1). Occurrences on F. excelsior mainly refer to on pollarded trunks. The habitat (indicated in 14 localities) included broad-leaved deciduous forests (5), sea-shore (3), cultural landscapes (2), Quercus forests (2), ravines (2), Betula forests (1), boulder fields (1), mixed deciduous forests (1), and Picea forests (1). In several localities both corticolous and saxicolous occurrences were noted. Pannaria sampaiana often occurred in habitats with many oceanic or moisture-demanding lichen species: Degelia plumbea, Lobaria amplissima, Lobaria virens, Nephroma laevigatum, Normandina pulchella, Pannaria conoplea, P. mediterranea, P. rubiginosa, Peltigera collina, Pseudocyphellaria crocata, and Sticta spp. Recorded aspects were northern (3), southern (3), western (2), eastern (2), northeastern, northwestern, southwestern, and southeastern (all 1). Radiation on the sites varied from well-lit to shaded. Discussion. In Norway, Pannaria sampaiana is a species of both rocks and tree trunks (mainly broad-leaved trees such as Quercus spp., Fraxinus excelsior, and Populus tremula). In the southern and westernmost parts of its world range, however, it rarely occurs on rock (Jørgensen 1978, Purvis 1992d)
Threats: Results. Recorded threats include forestry (137, 144, 872, 1463, 2614, 2699), building on the site (3574), collecting (1466), and lack of pollarding (3240)
Status: Nine of the old localities were investigated; the species was present in 4, recorded as uncertain in 4, and extinct in 1. Nine new localities were discovered, and the species is hence known to occur in 13 localities. One site (3529) is within a protected landscape area, two sites (2616, 2614) are within proposed nature reserves. At its northernmost known locality it appears to be extinct due to forestry (see also Holien & Hilmo 1991)