Peat Landscapes

Raised Bog
Courtesy IPCC.ie

As well as mountainous peatlands (discussed in a previous section), Ireland has even more peat soils (see for yourself here. Around 25% of the area of Ireland (1.7 million hectares) are made up of peat soils. Peatlands in Ireland have been here since the last Ice Age ~10,000 years ago, and are therefore one of the oldest parts of our natural heritage. Peatlands are characterised as raised bogs, blanket bogs or fens and have accumulated over thousands of years providing the raw material turf for generations of Irish people, who used it as both a source of heat and a commodity. Peatlands are important for another, more topical reason also, as they store vast amounts of carbon which can be released to the atmosphere when turf is burned or bogs are drained/damaged. Peatlands take in carbon over centuries and store it, acting as a ‘carbon sink’. When the peat is burned as turf, it is a ‘carbon source’.

Peatlands are wetland ecosystems formed by thousands of years of decaying plant material under waterlogged conditions, as the saturated soil limits decay, plant material accumulation exceeds the rate of decay, over thousands of years, the peat bogs we see today are formed. Peat forms at around 0.5-1cm per year, or 5-10m over 10,000 years, which is why we have such developed peat bogs here in Ireland. The major types of peatlands in Ireland are raised bogs, blanket bogs and fens, bogs receive nutrients exclusively from rainfall and therefore lack nutrients, fens get nutrients from surface and groundwater along with precipitation meaning they tend to be more rich in nutrients. Raised bogs began forming 10,000 years ago, blanket bogs ~4000 years ago.

Peatlands are used for agriculture when they are drained and used for the grazing of cattle and sheep. They are also used for forestry as 43% of Ireland’s total forest is located on peat soils, mainly blanket bog. Peatlands are also used for the extraction of peat, which is used as a source of electricity generation in Moneypoint (although this is set to be phased out for greener fuel), turf used for domestic fuel, horticultural products such as compost, and raw material for chemical products. It is thought that 100,000 hectares of peatland is under active production, while half a million hectares may be being used for domestic turf consumption.

Modern peatlands have been used to plant trees on, cut away by domestic and commercial turf extraction, eroded by agricultural reclamation and grazing, damaged by roads and railways and invaded by non-native species, meaning they are under significant threat.  Peatlands also act as flood barriers as they absorb and store so much water, so when they are drained for agriculture or other uses, this function is lost meaning flooding is more likely.