We conducted a phytosociological analysis of submontane beech forests on calcareous-silicate bedrock at the upper course of the Nadiža River and its tributaries (the brooks of Beli Potok / Rio Bianco, Črni Potok / Rio Nero, Plazi Potok, Globotnik, Legrada / Lerada, Jamnik / Jamjak, Veliki Potok). Based on comparisons with similar beech communities in geographically closer areas we classified them into the new association Polysticho braunii-Fagetum sylvaticae. The new association was subdivided into five subassociations: luzuletosum luzuloidis, stellarietosum montanae, typicum, caricetosum albae and saxifragetosum cuneifolii. The beech stands at the village of Staro Selo and several beech stands at Podbela were classified into the association Ornithogalo pyrenaici-Fagetum.
 
 Izvleček
 Fitocenološko smo raziskali submontanske bukove gozdove na karbonatno-silikatni geološki podlagi ob zgornjem teku reke Nadiže in njenih pritokov (Beli potok / Rio Bianco, Črni potok / Rio Nero, Plazi potok, Globotnik, Legrada / Lerada, Jamnik / Jamjak, Veliki potok) in jih na podlagi primerjav s podobnimi bukovimi združbami v geografsko bližnjih območjih uvrstili v novo asociacijo Polysticho braunii-Fagetum sylvaticae. Členili smo jo v pet subasociacij: luzuletosum luzuloidis, stellarietosum montanae, typicum, caricetosum albae in saxifragetosum cuneifolii. V asociacijo Ornithogalo pyrenaici-Fagetum smo uvrstili bukove sestoje pri Starem selu in nekatere bukove sestoje pri Podbeli.