World distribution: The distribution is centered in Asia, but extends through more humid parts of Europe and to the Pacific Islands (Jørgensen 1972b, Brodo & Hawksworth 1977, Smith 1984). Bryoria smithii is considered to be an oceanic lichen (Schauer 1965). The European distribution is mapped by Hawksworth (1972), based upon Schauer (1965; for the mountains of Central Europe) and Jørgensen & Ryvarden (1970; for Scandinavia). Bryoria smithii is an exceptionally rare species in the British Isles (Hawksworth 1972), probably extinct from north Wales and Scotland (Purvis 1992a). It is also rare in Central Europe (Schauer 1965, Wirth 1987). In Scandinavia it is considered endangered in Sweden (Aronsson et al. 1995) and Finland (known from 3-4 localities in the south; Kuusinen et al. 1993), and is absent from Denmark (Alstrup & Søchting 1989)
Ecology: Results. The species was mainly collected on rock walls (21 records); corticolous records are from Betula pubescens (2), Salix sp(p). (2), Juniperus communis (1), Alnus glutinosa (1), and Sorbus aucuparia (1). The aspect, recorded in 11 localities, was northern to eastern, where it often occurred on steep, more or less vertical rocks or on boulders. The localities were situated within forests or in open heaths near lakes or waterfalls. Most localities were situated in the lowland. The highest locality (2352, 520 m) represented an old Picea forest with Usnea longissima and Bryoria bicolor in southeastern Norway. Associated species along the coast include Hypotrachyna laevigata, Parmelia omphalodes, P. saxatilis, Platismatia glauca, P. norvegica, Sphaerophorus globosus, and Usnea fragilescens agg. Cetrelia olivetorum, Flavoparmelia caperata and Parmotrema chinense were noted from neighbouring trees in one rock wall locality. Discussion. The ecology of Bryoria smithii resembles that of the more common B. bicolor (Räsänen 1939, Degelius 1948, Schauer 1965, Jørgensen & Ryvarden 1970, Kuusinen et al. 1993). Outside Scandinavia it is mainly an epiphytic species both in England (Hawksworth 1972) and Central Europe where it grows in microclimatically humid forests (Suza 1933), e.g. near waterfalls (Schauer 1965). In England the species is mentioned under the alliance 'Parmelion laevigatae' that typically grows on very acid substrates with pH 3.75-4.6 (James et al. 1977). Bryoria smithii is considered an indicator of long ecological continuity (Rose 1976, Kuusinen et al. 1993). The isolated locality in Vestfold (2352) indicates that the species is able to thrive in old Picea abies forests in eastern Norway. A similar extension of the distribution area of oceanic species from open habitats along the west coast to old spruce forests with a humid microclimate in eastern parts of Norway has previously been indicated for the ecologically similar species Platismatia norvegica (Ahlner 1948) and Usnea longissima (Gauslaa et al. 1992). The other locality in eastern Norway, a 135 year old record from Oslo (761) with no ecological data supplied, is probably from a similar type of habitat since the collector, T.M. Fries, made several collections of Usnea longissima with the same date and locality name
Threats: Results. Assumed threats were forestry (4), air pollution (1), closure of forest (1). Discussion. Reduced radiation due to closing of forests or plantation of Picea abies, threatens Bryoria smithii in the more open habitats near the southwestern coast. Since the species is often recorded near waterfalls, a change in waterflow is likely to affect the species. Air pollution is a possible threat, although not so far documented for this lichen
Status: Twelve old localities were visited, the species was found in 6, assumed to be extinct in 1 and considered uncertain in 5. Two new localities were found during search for other threatened species. All visited localities except one (2174) had few specimens, thus emphasizing the rarity of the species. Locality 1754 is within a nature reserve
Specimens in other herbaria, litterature, etc.