Early stadiums of floodplain forest succession in a wide river beds upon an example of Bečva

In the years 1999-2001 early stadiums of succession development of a floodplain forest were monitored in the wide bed of the Bečva River formed during the floods in 1997. Changing site conditions were investigated and the vegetation of pebble beds was repeatedly mapped in detail. In dependence on the site conditions main types of biotopes were described. The vegetation data were evaluated in accordance with the life form and ecological claims of the identified species. The results indicated an increasing differentiation of the originally relatively homogeneous environment owing to fluvial processes and progress of vegetation. Generally hemicryptophytes and hemiheliophytes were thriving above all, the dominance of Phalaris arundinacea was still growing. As for the woody species, especially willows asserted themselves from the beginning, solitarily and weaker in vitality representatives of other genera were present at drier sites. The identified specimen of Myricaria germanica was probably planted artificially. As concerns neophytes, only Reynoutria japonica was spreading significantly but in a very uneven way. Generally, this development of similar communities only little documented in this region corresponds to STG Saliceta fragilis inf.