EN
Clear−cutting impacts site conditions seriously. However, in nutrient−poor sites the effects of stand removal can be minor than in nutrient−rich sites. The aim of this work was to assess whether the clear−cut can improve species diversity of ground Cladonia species, which decline has been observed in forest communities. In stands of different age classes (10, 11−20, 21−40, 41−60, 61−80, 81 years) in the Przymuszewo Forest District (northern Poland) ground Cladonia species and their cover were recorded on research plots (10×15 m). A total of 24 species were identified in the study area. There were more Cladonia species and they were more abundant in young stands (<20 years old) than in stands older than 60 years. Nine species are significantly more frequent and demonstrated high fidelity in young stands and only one was characteristic for old stands. Composition of Cladonia species depended primarily on stand age and subsequently on canopy or bryophyte cover. In nutrient−poor sites clear−cutting is favourable for Cladonia species diversity.