World distribution: Leptogium hibernicum is known from western Europe, Africa, and South America (Jørgensen 1973, Galloway & Jørgensen 1995). In northwestern Europe the species show a western British Isles - western Norway disjunct distribution. In Fennoscandia it is restricted to Norway
Ecology: Results. Leptogium hibernicum has only been found on old, moss covered, pollarded trunks of Fraxinus excelsior in the old agricultural landscape. It usually occurred on mosses on the north-facing side of the trunks. Within the cultural landscape the habitat (indicated in all localities) included boulder fields (3) and pastures (2). In Rogaland it grew in south-facing slopes (2307, 2308), whereas its aspect in Hordaland was western (3531), northeastern (3234), or northwestern (3236). Discussion. In Norway, the species is restricted to the old agricultural landscape. It always occurs in sites rich in oceanic lichens. Two particularly species-rich localities are 2308 (see list in Arvidsson 1986) and 3234 (with, e.g., Rinodina isidioides and Megalospora tuberculosa - both typical of old hardwood forests in lowland Britain, according to Rose 1976). In the British Isles L. hibernicum belongs to the Scottish-Hibernian distribution group of western species, and is dependant on a very humid climate with more than 200 rain days per year (Coppins 1976)
Threats: Results. Recorded threats were forestry (1), land development (1), and lack of pollarding (1). Discussion. Since the species is dependant on the old cultural landscape, it is highly threatened. Old pollards which are no longer naved may easily be felled by strong winds, and a number of such felled pollards were observed in Sævareidberget protected area (3531)
Status: Leptogium hibernicum was first found in Norway in 1947 (2307; Jørgensen 1973), and a second site was discovered in 1985 (2308). The two old localities were investigated, and the species was present in both. Three new localities were discovered, but the species is today known only from a total of 7 trees. One locality (3531) is within a protected landscape area, whereas one (2308) is a nature reserve
Notes: According to the management plan for the Sævareidberget protected landscape area (3531), naving will be carried out. Some recently naved pollards were observed in 1994, but most trees remained to be treated..
Specimens in other herbaria, litterature, etc.