Lowland wetlands
Marshes, fens, swamps, bogs... Our cool damp
climate has aided the widespread development of wetlands in
Wales.
The term Wetlands includes a wide range of habitats. Some
are only seasonally flooded or waterlogged, such as marshy
grassland. Others are wet all year round, for example
mires.
These are the main types of wetlands in Wales:
Grazing marshes
Grazing marshes are flat expanses of formerly ill-drained land
which occur next to rivers and estuaries. Many grazing marshes have
been drained and farmed to create fertile grasslands for dairy
farming; others are more natural with common reed and other swamp
plants. Ditches on many grazing marshes provide a home for a wide
range of invertebrates and plants, while even the most heavily
farmed grasslands can be important for wading birds like lapwing
and curlew.
Where to find them
In the main estuaries and in the valleys where the largest Welsh
rivers have flooded and left silt behind.
Fens
Fens are usually peat-forming habitats, kept wet
by surface runoff, groundwater or rain. Those with the
greatest variety of plants and animals are fed by
water derived from limestone rock or other calcareous
deposits. More common in Wales are fens where the
water is acid and has few nutrients.
Where to find them
Some of the richest fens for plants and animals are found in
Anglesey, the Llŷn Peninsula, the Brecon Beacons National Park and
Pembrokeshire.
Bogs
Bogs are a particular type of peatland habitat fed exclusively
by rain. This happens most often when a fen
has accumulated enough peat to rise above river or
groundwater level.
There are two main types of bogs:
- raised bogs, which occur as isolated domes of peat scattered
throughout Wales
- blanket bogs, which cover large areas of land,
particularly in the uplands.
Bogs can accumulate as much as 8 m of peat and grow upwards at
the rate of up to 1 mm of peat a year.
Bogs have their own range of plants and animals which have
adapted to a wet, acidic and nutrient poor environment. They
include plants such as bog mosses and insectivorous plants such as
sundew, which trap insects on the sticky hairs of their
leaves.
Where to find them
Two of the best known examples are Cors Caron near Tregaron and
Cors Fochno near Borth, both in Ceredigion.
Swamps
Swamps are usually subject to year-round flooding and occur most
often within lake and river margins. Tall grasses and sedges
are the most common plants, especially the common reed.
Reedbeds formed by this attractive grass are important for
birds such as the reed warbler and bearded tit.
Wetlands in history
Wetlands enjoy a special place in Welsh folklore. The earliest
people thought that wetlands were the link between the world of man
and the world of the spirits. Many gifts to the gods were left in
wet places – including the Llyn Cerrig Bach hoard on Anglesey,
the magnificent bronze shield of Rhos Rydd in Ceredigion, and the
enigmatic figurine of a man from Strata Florida in
Ceredigion. Bodies have also been found in Welsh bogs but
there is no definite evidence that people were sacrificed
there.