Wicklow Mountains - Habitat

Habitat

See also: Flora of Ireland and Fauna of Ireland

The primary habitat of the uplands consists of heath and bog. The mountain blanket bogs formed around 4,000 years ago as a result of a combination of climate change and human activity. Prior to this, the mountains were cloaked with pine forest. A change in the climate to wetter and milder weather left the ground waterlogged and leached nutrients from the soil, leading to the formation of peat. Mountain blanket bog is found in areas above 200 metres (660 feet) in altitude and where there are more than 175 days rainfall a year. The most important builders of peat are the Sphagnum bog mosses. Carnivorous plants such as sundews and butterworts are specific to boglands and bog asphodel and bog cotton are also common. Bog water is important for the reproduction of dragonflies and damselflies and the Wicklow mountain bogs also support insects such as pond skaters, whirligig beetles, water boatmen and midges as well as the common frog and the viviparous lizard. Wading birds such as snipes, curlews and golden plover feed in the waterlogged bogland.

Due to drainage of water from the bogs as a result of human activity, most of Wicklow's peat has dried out too much for Sphagnum mosses to grow and moorland and heath vegetation has taken over. Active peat building is still occurring at some sites, most notably the Liffey Head Bog. Common heather (or ling) and bell heather are the most common moorland plants along with bilberry (or fraughan, as it is known in Ireland), bog cotton, deergrass and purple moor grass. Bird species found on the Wicklow moorland include red grouse, meadow pipit and skylark. Birds of prey found in the uplands include kestrels, hen harriers, merlins and peregrine falcons. The latter of these are protected species. The uplands are used for sheep grazing and so the moorland is periodically burned to keep the growth of heather in check and encourage growth of grasses.

Red deer, once native to Wicklow but hunted to extinction, were reintroduced on the Powerscourt Estate in the 18th century. Japanese sika deer were also imported by the Powerscourt Estate and have interbred with the red deer. All deer found in the Wicklow Mountains are descended from the Powerscourt herd and are either sika deer or hybrid red-sika deer. Other mammals occurring include feral goats, mountain hares, badgers, stoats, otters, red squirrels, grey squirrels and bats. The Irish Elk is an extinct species of deer that lived in the Wicklow Mountains c. 11,000 years ago, remains of which were discovered in great quantities in Ballybetagh Bog near Glencullen. Wolves were also once native to the mountains but hunted to extinction in Ireland: the last wolf in Wicklow was killed at Glendalough in 1710.

Widespread clearance of forest began in the Bronze Age and continued up until the early 20th century. Afforestation programmes began in the 1920s and accelerated in the 1950s with the widespread planting of conifer forest, especially in upland moorland areas previously considered unsuitable for planting. The dominant tree is the sitka spruce, accounting for 58% of forest plantations, with lodgepole pine, Norway spruce, Scots pine, larch and Douglas fir also planted. Biodiversity is low in the conifer plantations because they are not native tree species. Broadleaf plantations are rare, accounting for less than 10% of forest.

The young rivers in the upper glens are spawning grounds for salmon and brown trout. Arctic char, isolated in the Wicklow lakes following the end of the last ice age, have been recorded in Lough Dan and the lakes of Glendalough but are now believed extinct. A programme to reintroduce them into the Upper Lake at Glendalough commenced in 2009.