Floating mat

A floating mat (German: Schwingrasen) is a layer of mosses and other, especially stoloniferous, plants that grows out from the shore across the surface of a lake or pond.

In bog ponds, floating mats of peat moss form as water levels fall and nutrients accumulate.

Reeds or rushes growing by the lakeshore can eventually cut these mats off, which results in a floating island.

Beneath the floating mats, peat is formed, which slowly sinks downwards and gradually fills the water body.

The edges of nutrient-rich waterbodies are colonised by reeds (Phragmites australis), bulrushes (Typha ssp.