A floating mat (german: Schwingrasen) is a layer of

moss Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hor ...

es and other, especially stoloniferous, plants that grows out from the shore across the surface of a lake or pond. This type of habitat is protected and is designated in the European

Habitats Directive The Habitats Directive (more formally known as Council Directive 92/43/EEC on the Conservation of natural habitats and of wild fauna and flora) is a directive adopted by the European Community in 1992 as a response to the Berne Convention. The E ...

as "LRT No. 7140 Transition and Floating Mat Bogs". Floating mats are not always capable of bearing weight. There is a risk of drowning when walking on them.

Formation

The formation of floating mats is a process of

sedimentation Sedimentation is the deposition of sediments. It takes place when particles in suspension settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to the ...

in water bodies. In

bog pond A bog pond (german: Moorauge) is a waterbody in the middle of a raised or kettle bog, formerly also in percolating mires (''Durchströmungsmooren''). It is also called a bog pool, bog eye, raised bog kolk, bog kolk or just kolk. Bog ponds owe th ...

s, floating mats of

peat moss ''Sphagnum'' is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, peat moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of ''Sphagnum'' can store wa ...

form as water levels fall and

nutrients A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excret ...

accumulate. In

eutrophic Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytoplank ...

waters, the formation of floating mats is caused by underwater peat that floats to the surface and is colonised by plants. The vegetative mats are held together by their root systems. Reeds or rushes growing by the lakeshore can eventually cut these mats off, which results in a

floating island A floating island is a mass of floating aquatic plants, mud, and peat ranging in thickness from several centimeters to a few meters. Floating islands are a common natural phenomenon that are found in many parts of the world. They exist less co ...

. If the floating mats are stable and large enough, even trees can grow on them, as at the Kleiner Arbersee. Beneath the floating mats,

peat Peat (), also known as turf (), is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem covers and is the most efficien ...

is formed, which slowly sinks downwards and gradually fills the water body.

Flora and fauna

In nutrient-poor to moderately nutrient-rich, acidic waterbodies, floating mats form out of

es, ( feathery bogmoss ''Sphagnum cuspidatum'', species of the complex ''Sphagnum recurvum'' s.l.) or brown mosses (''Scorpidium scorpioides''). Furthermore, floating mats are colonised by characteristic species of the small sedges such as the

bog sedge Bog sedge is a vernacular name for any of the following plants: *'' Carex limosa'' * ''Carex magellanica'' subsp. ''irrigua'' (formerly ''Carex paupercula'') *''Kobresia ''Kobresia'' is a genus of plants in the sedge family. They are sometimes ...

(''Carex limosa''), (''Carex rostrata''), beak sedge (''Rhynchospora'' ssp.), Rannoch-rush (''Scheuchzeria palustris'') and

marsh cinquefoil ''Comarum palustre'' ( syn. ''Potentilla palustris''), known by the common names purple marshlocks, swamp cinquefoil and marsh cinquefoil, is a common waterside shrub. It has a circumboreal distribution, occurring throughout North America, Europe ...

(''Potentilla palustris''). The edges of nutrient-rich waterbodies are colonised by reeds (''Phragmites australis''),

bulrush Bulrush is a vernacular name for several large wetland grass-like plants *Sedge family (Cyperaceae): **''Cyperus'' **''Scirpus'' **'' Blysmus'' **''Bolboschoenus'' **''Scirpoides'' **''Isolepis'' **''Schoenoplectus'' **''Trichophorum'' *Typhacea ...

es (''Typha'' ssp.),

hop sedge Hop sedge is a common name for several species of sedges: * ''Carex lupulina'' — native to eastern North America * '' Carex lupuliformis'' — usually called false hop sedge, also native to eastern North America * ''Carex pseudocyperus ...

(''Carex pseudocyperus'') and

cowbane Cowbane is a common name for several plants and may refer to: * ''Cicuta virosa'', a poisonous species of ''Cicuta'', native to northern and central Europe, northern Asia, and northwestern North America * ''Oxypolis ''Oxypolis'' is a small genus ...

(''Circuta virosa''). Floating mats are habitats for shelly

amoeba An amoeba (; less commonly spelled ameba or amœba; plural ''am(o)ebas'' or ''am(o)ebae'' ), often called an amoeboid, is a type of Cell (biology), cell or unicellular organism with the ability to alter its shape, primarily by extending and ret ...

such as ''Amphitrema'' sp. and

lake fly The Chironomidae (informally known as chironomids, nonbiting midges, or lake flies) comprise a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae. Many species ...

larvae.

Threats

* Drainage *

Peat cutting Peat (), also known as turf (), is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem covers and is the most efficien ...

* Use, especially by forestry and agriculture, but also for leisure pursuits * Nutrient introduction, fertilisation,

eutrophication Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytopla ...

References

Literature

* * Hutter, Claus-Peter (ed.); Alois Kapfer & Peter Poschlod (1997): ''Sümpfe und Moore - Biotope erkennen, bestimmen, schützen.'' Weitbrecht-Verlag, Stuttgart, Vienna, Berne. {{ISBN, 3-522-72060-1 Bogs

Formation

Flora and fauna

Threats

See also

References

Literature