The class Isoëto.Nano-Juncetea includes vegetation of low-growing annual wetland graminoids and dicot herbs. The life cycle of many of these species can last for as little as 4–6 weeks, but can be shortened or prolonged depending on water availability and temperature. Seeds of these plants are able to survive several decades in the seed bank on the bottom of water bodies. These life history characteristics enable these plants to survive in unpredictable wetland environments, which dry out in irregular intervals of a few or several years. Optimum conditions for the development of this vegetation are in places where water drops down to the level of the bottom, and then dries out slowly. After drying out, succession proceeds rapidly towards vegetation of taller annual or perennial herbs, which outcompete the low-growing annuals. This class has a broad range across Eurasia including the Mediterranean and North America. In the Czech Republic it is particularly common in fishponds.