The forests of occasionally flooded areas on river and stream floodplains, as well as on temporarily flooded lake shores, where the soil is enriched with the sediments of flood water. The species composition and structure of the forest depends on the part of the floodplain it grows on. Alluvial forests have formed on the lower parts of the floodplain, i.e. the parts that remain under the flood water for longer. The higher shore embankments are covered by riparian mixed forests (91F0).
Black alder, and occasionally ash, dominate the tree layer of an alluvial forest with a thinner peat layer; in the rather species-rich herb layer, species of fresh boreo-nemoral forests grow alongside marsh plants.
Alluvial forests can be seen mainly along the Pedja, Koiva, Mustjõgi, Pärnu, Halliste, Raudna, Lemmjõgi, Võhandu, Piusa, Poruni, and Jänijõgi rivers.
Includes the habitat type 1411 (minerotrophic stagnant water swamp forest site type) according to Paal.