Conservation status and future perspectives of the forest communities of Tilio platyphyllis-Acerion pseudoplatani Klika 1955 alliance in the Sudetes and their foothills

Killarney Fern (Trichomanes speciosum Willd., Hymenophyllaceae) is one of the most endangered and interesting ferns in Europe which forms independent gametophyte colonies. In Poland it has been reported for the first time from two localities in the Westsudetian Highland, Lower Silesia. They are the most eastern outposts of this taxon in Europe, suffering the most severe climatic conditions in the extent of its occurrence. On both sites gametophytes occurred in horizontal rock fissures in Upper Cretaceous sandstone, surrounded by degraded eastern oak-hornbeam forests. Sixth year of its occurrence in Poland shows dynamic changes of its population state. Population occurred in the cave near Złotoryja has decreased between 2002 and 2006, to be almost extinct, but by the last two years it increased to half of its previous state. Gametophytes found in locality near the Lwówek Śląski (Panieńskie Skały) in years 2002-2004 has not been observed in 2008.