This association includes tall, dense reed beds of Phragmites australis, a grass with a broad ecological range, occurring in oligotrophic to eutrophic, acidic to basic, and even brackish wetlands. It occurs in fishpond littoral zones, oxbows, alluvial pools, flooded pits, ditches, channels, on fluvial deposits, mire edges, abandoned wet meadows and flooded depressions on arable land. This kind of marshes is mostly found at a water depth of 10–50 cm, but it can also occur both in much deeper water or on sites that are not flooded at all. In the Czech Republic this is the most common vegetation type of marshes, occurring from the lowlands to montane areas.