Sphagnum Moss
 
Peatland
     

Formation

Raised bog
Raised bog. Click here to view detailed image

Raised Bogs

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.

Movie camera imageClick here to view Raised bog animation

 

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