Polypodium vulgare L. in the communities of acidophilous and thermophilous oak forests in the Sudety Mts and their foreland

In the Sudety Mts and their foreland, Polypodium vulgare is the main component of the rocky plant communities classified within the class Asplenieta trichomanis. In the forest communities, this fern occurs most frequently in the patches of forests of the alliance Tilio platyphyllis-Acerion pseudoplatani. Phytosociological and floristic research, conducted from 2008 to 2011 in acidophilous and thermophilous oak forests of the Sudety Mts and their foreland, revealed that P. vulgare was an element of different importance in the herb layer in these communities. P. vulgare was mostly observed in the stands of oak forests at the altitude above 300 m a.s.l., in west, southwest or south-facing slopes. P. vulgare was recorded mainly in the herb layer of thermophilous oak forests (ass. Sorbo torminalis-Quercetum and oak forests with the occurrence of Silene vulgaris and Galium verum) and acidophilous oak forests with the occurrence of Festuca pallens and Cotoneaster integerrimus developed in extremely xerothermic sites. For the latter community, P. vulgare is a differential species.