Raised bogs are found in lowland areas, generally below 150m,
such as river valleys, lake-basins, and between drumlins. They
are known as raised bogs because the bog surface is raised in
the middle, like a dome. The surface of a raised bog is a mixture
of pools, raised mossy hummocks and flatter lawns, and is colonised
by plants and animals adapted to the acidic conditions and low
levels of nutrients found there. This favours the growth of
plants such as Heather, Cottongrasses and, most importantly,
Sphagnum mosses. These plants die to form peat that is markedly
different from fen peat and often very deep - up to 12m.
Raised bogs began to form in Ireland around 10,000 years ago,
at the end of the last ice-age. They developed when the peat
accumulating in fens became isolated from the groundwater. When
the roots of plants lose contact with the groundwater, their
only source of nutrients is from rainwater and the atmosphere.
here to view Raised bog animation