The largest alluvial forest in the Czech Republic grows at the confluence of the Morava and Dyje rivers. Residual alluvial forests can be found in the area of the confluence of the Labe and Cidlina rivers (Libický Alluvial Forest Natural Reserve), and on the banks or in the headwater area of the Morava and Dyje rivers.
This year's PostEurop announced the annual theme is "Forests". Therefore the Czech Post issued the single stamp depicts the alluvial forest and its environment on May 4, 2011. This stamp was designed by Adolf Absolon.
The presence of a stream or river, or a high level of underground water leads to a lower amount of oxygen in the soil and subsequent reduction processes. The products of the processes contribute to the typical bluish colour and special smell of the so-called gley soil.
Primary trees found include poplar (Populus L.), oak (Quercus L.) , ash (Fraxinus L.) , elm (Ulmus L.) , alder (Alnus L.) , willow (Salix L.) , lime tree (Tilia L.) . Shrubs and small trees, such as cherry (Prunus serotina) , honeysuckle (Lonicera) , cornel (Cornel) , viburnum (Viburnum) , elder (Sambucus) , are present at places with more light.