Cutting for domestic fuel has caused the greatest decline in Northern Ireland peatlands. With the demise of native woodlands, peat became the major source of fuel in Ireland during the 17th and 18th centuries. Rights to cut peat on small plots of land, known as turbary rights, were allocated to landowners. Traditionally peat was cut by hand using a special turf-spade known as a sleán or slane. Hand-cut turf production in Ireland reached its peak in 1926 when over six million tonnes of turf was cut.
Over the years the amount of turf cut declined steadily until World War II, when peat became a vital domestic fuel source again as the supplies of coal from Great Britain almost ceased. The deep peat in raised bogs and the extensive areas of blanket bogs were cut extensively.
The use of fen peat as a source of fuel, known as mud turf, was less common because the peat is very shallow and cannot be cut with a spade. Instead, mud turf is gathered by digging a hole and mixing water with the peat, then tramping or "puddling" it with bare feet, shovelling it onto the bank and finally moulding it into blocks by hand. This was a very labour intensive process and was only practised in a few areas, such as Brackagh Moss in County Armagh.
After the War the low price of coal and oil kept peat cutting to a minimum, and by the 1970s the annual production of peat was down to about a million tonnes, mostly from the blanket bogs in the west. However, the introduction of tractor-drawn auger machines during the 1980s increased the amount of peat cut again. Since then mechanised peat extraction has become the norm in Northern Ireland and the tradition of hand-cutting turf has almost disappeared.
In Northern Ireland 77.5% of raised bogs have been cut for fuel. The majority of peat cutting was for domestic purposes, but the relatively limited commercial extraction for fuel has had important local effects. Commercial extraction needs planning consent, but the complexity of land ownership and turbary rights sometimes makes the distinction between commercial and domestic cutting difficult to determine.
46% of Northern Ireland's blanket bog has been subjected to hand-cutting for fuel. In recent years there has been a trend towards the tractor-mounted method, which is one of the reasons that blanket bog continues to disappear. Most mechanised cutting happens on peatland that has been hand cut in the past but at least 14% takes places on previously intact peatland.
In addition to the actual damage caused by removing the peat, two key biological aspects of the peatland habitat are adversely affected – the water balance and surface vegetation. Archaeological sites are often damaged or removed. For example timber structures can be cut through and have their survival threatened as the peat cover dries out.
The effects of mechanised turf cutting, the most widespread method in Northern Ireland, are much greater than hand cutting. Nearly all types of turf cutting need some level of drainage, but the areas and extent of drainage required for machine cutting are obviously much greater. Drainage leads to changes outside of the area being cut, caused by drying out the peat and altering the vegetation it supports. The channels left by machine cutting also act as drains, further increasing water removal from the ecosystem.
An example of the problems that mechanised cutting can cause is very evident at the Marble Arch Caves in Fermanagh. In 1989 it was noted that the volume and speed of the rivers entering the cave system from the blanket bogland of Cuilcagh Mountain had increased significantly. The caves had to be closed to visitors for health and safety reasons when water levels were high, which adversely affected tourism in the region. There is also concern that an increase in sediments in the river water could affect the stalagmite and stalactite formations within the cave. Research has since shown that machine cutting of peat on Cuilcagh Mountain contributed to the increased water in these caves.
Removing water from any peatland has an impact on the archaeological value of the site. Organic materials are preserved in peat because the high water content inhibits the presence and actions of microorganisms. Removing water can result in increased microbial activity, causing the decay of preserved organic material such as wooden containers, clothing, timber structures such as trackways and houses and even human remains.
Repeated cuts and machine travel on peatlands destroy the surface vegetation, which can erode and destabilise the entire surface of the bog. Research in Northern Ireland has shown that machine cutting decreases the height and biomass of the vegetation and rapidly reduces the invertebrate populations. Animals further up the food chain such as birds and mammals are directly affected as there is less food and poor cover for nesting.
The Department of the Environment (DoE) and the Department of Agriculture and Rural Development (DARD) have a number of measures in place to prevent unsustainable turf cutting practices in Northern Ireland. The Government has produced Conserving Peatlands in Northern Ireland - A Statement of Policy (PDF, 340 KB), which outlines the measures it will take to regulate commercial peat extraction. This policy also proposed a code of good practice for domestic extraction, which is now available as a booklet from the Countryside Management Division of DARD, "Peat Cutting - reducing the damage".