Its name indicates its size. With a height of 30 - 80 cm, the dwarf bulrush(Typha minima) is significantly smaller than other bulrush species. Its occurrence is an indication of an intact river landscape. It colonizes riparian areas with sandy, silty substrates, such as in fresh tributaries, and is a typical pioneer species of large alpine floodplains.
Without rearrangements of the river branches and the soil, the dwarf bulrush, which is weak in competition, would quickly be overgrown by higher-growing species such as reeds or willows. Like other flagship species of alpine floodplains, it requires natural dynamics to survive, which repeatedly create unvegetated sites for its reestablishment. These are optimal conditions for the dwarf bulrush, as it is a light-loving plant and does not tolerate shading.
In its reproduction, the small bulrush relies on mass and speed. It forms many fine seeds that can be transported by wind and water. It can also reproduce rapidly vegetatively via thick stolons.
The dwarf bulrush formerly had a large occurrence along the large river systems in the Alps as well as in the Alpine foothills. Due to consistent river regulation, it has experienced dramatic declines over the last 100 years. Today it is acutely threatened with extinction in the Alpine countries.
On the Tyrolean Lech, isolated remnants can still be found. Along with the populations on the Rhine and the Dornbirner Ach, these are the largest populations in the Alpine region. Thus, Austria bears the main responsibility for the conservation of the dwarf bulrush in Europe.