A formalized and supervised phytosociological classification of Alnion glutinosae and Alnion incanae in the Czech Republic is presented. Three associations of Alnion glutinosae (Thelypterido palustris-Alnetum glutinosae, Carici elongatae-Alnetum glutinosae and Carici acutiformis-Alnetum glutinosae) and seven of Alnion incanae (Alnetum incanae, Stellario nemorum-Alnetum glutinosae, Pruno-Fraxinetum, Carici remotae-Fraxinetum, Piceo-Alnetum, Ficario-Ulmetum campestris and Fraxino pannonicae-Ulmetum) were distinguished by the Cocktail method using sociological species groups. Information about their syntaxonomy, species composition, ecology and distribution is presented. Ellenberg’s indicator values were used to show the main ecological gradients responsible for the variation in the vegetation of these communities. The most important factors affecting this variation were temperature (for Alnion incanae) and soil reaction, nutrient availability and moisture (for Alnion glutinosae).
In the Czech Republic alluvial forests can be found in the floodplains of water courses from the lowlands up to the mountains (up to 1 000 m asl). Floodplain forests in-clude various vegetation types, such as alluvial forests with majestic oaks, stream floodplain forests and alder forests in spring areas, riparian willow forests and also wetland alder forests growing along river branches and in the vicinity of ponds. The flooding regime, the underground water level and the historical management determine the variability and species composition of alluvial forests. and Lužní lesy jsou v České republice rozšířeny v nivách vodních toků od nížin do hor; s výškovým limitem okolo 1 000 m n.m. Patří mezi ně rozmanité vegetační typy zahrnující tvrdé luhy s mohutnými duby, potoční luhy a prameništní olšiny, pobřežní vrbiny, ale také mokřadní olšiny, vázané vedle slepých ramen řek také na břehy a bezprostřední okolí rybníků. Proměnlivost a druhové složení lužních lesů v nivě určuje zejména záplavový režim, hladina podzemní vody a historický způsob obhospodařování.