Distribution and ecology of Trichocolea tomentella in Norway
Knut Rydgren, Odd E. Stabbetorp and Hans H. BlomK. Rydgren (email@example.com) Sogn og Fjordane Univ. College, Faculty of Science, PO Box 133, NO-6851 Sogndal, Norway. – O. E. Stabbetorp, Norwegian Inst. for Nature Research, PO Box 736 Sentrum, NO-0105 Oslo, Norway. – H. H. Blom, Norwegian Forest and Landscape Inst., Fanaflaten 4, NO-5244 Fana, Norway.
The liverwort Trichocolea tomentella is known from 65 localities in southern Norway. Almost half of these are in Hordaland county in Western Norway. T. tomentella has been observed at many localities (42%) in the last decade. On the other hand it has not been observed at 23% of the previously known localities after 1950, although a complete re-survey has not been performed. The species seems to be thriving in its main distribution centre in Western Norway, but in southeastern Norway urbanisation and modern forestry are major threats. In this part of Norway the species has probably gone extinct or is on its way to extinction at several of the localities. To preserve the species logging and draining close to springs, streams and gullies should be ceased. This will also preserve habitats that are species rich, in particular in bryophytes.