Formation

Northern Ireland peatlands

The cool wet climate of Ireland is ideal for producing peat, so peatlands form a characteristic part of the Irish landscape. In Northern Ireland, peatlands cover 12% of the land area, almost twice that covered by woodlands. Peatlands were much more extensive in Ireland up to the beginning of the 19th century, but have declined dramatically since then, particularly during the last 100 years. In the 1980s there was increased concern about the decline of peatlands throughout the United Kingdom and Ireland, but many cases lacked detailed information about the extent of peatlands, so it was difficult to measure the losses.

In 1986 The Department of the Environment commissioned a survey to assess the extent of peatlands in Northern Ireland. This survey aimed to reveal sites of possible conservation interest and provide a framework for more detailed ground surveys. Using aerial photographs, the survey managed to differentiate between raised bog and blanket bog, although it was less successful at identifying areas of fen. These aerial photographs highlighted losses of peatland by cutting and erosion, but could not determine how much peatland was lost to agriculture and forestry.

The Northern Ireland Peatland Survey published in 1988 concluded that the total area of peatland in Northern Ireland, excluding fen, was approximately 167,580ha:

• 15% (25,196ha) were raised bogs
• 85% (142,384ha) were blanket bogs

Map of peatland areas in Northern Ireland

The largest areas of raised bog are in the lowland corridor extending from the Lough Neagh Basin north along the Bann Valley in the east. There are also small raised bogs in the valleys between drumlins in Counties Down, Armagh and Fermanagh.

The increase in altitude and rainfall towards the west of Northern Ireland results in large areas of blanket bog. In the east the largest proportion of blanket bog is found on the Antrim plateau.

The decline of peatlands in Northern Ireland

Raised bog

Peat milling

Only 8% of raised bog in Northern Ireland has not been cut or drained in some way. Since the felling of native Irish woodlands in the 17th and 18th centuries, peat has become the dominant local fuel. In the first half of the 20th century a large proportion of raised bogs were lost due to hand-cutting for fuel, and this has become increasingly mechanised during the second half of the century. The horticultural industry has also had an adverse effect on raised bog, largely as a result of agricultural drainage.

There is also evidence that areas of raised bog continue to decrease. The Northern Ireland Countryside Survey (NICS) monitored changes in land use and found a decrease of 8% in wet bog vegetation in the lowlands between 1992 and 1998, probably due to drainage and overgrazing as much as peat cutting.

Blanket bog

Peat cutting

Blanket bogs have declined in a similar way to raised bogs, with only 15% remaining intact. Blanket bogs have been used as a source of fuel and for rough grazing in Ireland for centuries, with organised reclamation of accessible areas of blanket bogs starting in the early 19th century. A large proportion (46%) of blanket bog in Northern Ireland has at some time been cut for fuel.

However, upland peatlands have declined further in the second half of the 20th century because of commercial tree planting, increased grazing and, most recently, mechanised cutting using tractor-drawn auger machines. NICS recorded a decrease of 25% in wet bog vegetation in the uplands between 1992 and 1998.

Fens

The area of fens in Northern Ireland is difficult to estimate as their small size and fragmented distribution make them difficult to survey in the same way as bogs. However, an extensive survey of fens in Counties Down and Armagh between 1993 and 1994 showed that this type of habitat is usually found in hollows between drumlins. Like bogs, fens are being damaged and destroyed at an alarming rate by in-filling, development, eutrophication and agricultural reclamation. NICS recorded a decrease of 18% in fen habitat between 1992 and 1998.

The future

At some point in the future, the Environment and Heritage Service plans to use recent advances in aerial photography and satellite imagery to undertake a further survey to reevaluate the current distribution of peatlands in Northern Ireland.