Vegetation dominated by Calamagrostis pseudophragmites occurs on gravel bars of submontane fast flowing rivers. The gravel bars are situated above or at the mean annual water level. The vegetation can be disturbed by strong but brief floods that cause erosion and translocation of accumulated sediments to elsewhere in the floodplain. This vegetation occurs on the Ostravice river in north-eastern Moravia and the Jizera river in eastern Bohemia. In the past it also occurred along other eastern Bohemian rivers.