Riverside, lakeside and seaside alder, birch or pine galleries and cordons of the boreal, boreonemoral and boreosteppic zones, of the high mountains of the nemoral zone and of their piedmont influence region, dominated by Alnus incana along the montane and submontane rivers of the Alps, the Carpathians, the northern Apennines, the Dinarides, the Balkan Range, the Rhodope Mountains and neighbouring regions, by Alnus incana or Alnus glutinosa in boreal Fennoscandia and northeastern Europe, by Betula pendula or Pinus sylvestris in western Siberia. In the herb layer, nitrophilous and hygrophilous species dominate: Aegopodium podagraria, Chaerophyllum hirsutum, Petasites hybridus, Crepis paludosa and Caltha palustris ssp. laeta.