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Irish Heathlands

Heathlands are open areas of ground, generally on poor soils and with few trees. In Ireland heathlands form in a range of soil and weather conditions. They are found in upland or lowland areas, inland and on the coast. Heathland can form on shallow peaty soils, leached calcareous soils, sandy soils and shallow mineral soils. There are many different forms of heathland and they're not all heathery. Some are dominated by grasses, mosses or lichens. Others are dry or wet. The main habitats present in heathlands are dry open heath, bare sandy soil, wet heath, bogs and open water. Heathlands are a sanctuary for wild nature in urgent need of conservation.

IRISH HEATHLANDS
The broadest classification of heathlands divides them into two main types: wet heath and dry heath depending on the degree of wetness of the soil or the severity of the climate.

Up close there are five different types of heathland found in Ireland. These are:
1. Dry Siliceous Heath
2. Dry Calcareous Heath
3. Heaths on Sand Dunes
4. Wet Heath
5. Montane Heath

1. DRY SILICEOUS HEATH
Dry siliceous heath can be found on flat to steeply sloping ground in upland and lowland areas. The underlying soils are relatively dry or free-draining but are acid and poor in nutrients. The typical vegetation includes Ling Heather, Bell Heather, Bilberry, low-growing Western Gorse, prostrate Juniper, Crowberry, Bearberry and Cowberry. Example The Great Sugarloaf Mountain, Co. Wicklow.

2 DRY CALCAREOUS HEATH
Dry Calcareous Heath occurs mainly in limestone areas on rocky ground or on shallow soils that are well-drained and base-rich. Leaching of the surface layers of the soil is common and this results in the proliferation of plants that would normally be associated with acid soils. The vegetation includes Ling Heather, Purple Moor Grass and Tormentil, in addition to a range of grasses and broad-leaved herbs normally associated with grasslands. Example Black Head, Co. Clare.

3 HEATHS ON SAND DUNES
Fixed dunes are stabilised ridges or hills of sand with a more or less complete cover of vegetation, and where humus has accumulated in the soil. The vegetation in such areas can be dominated by heath communities. Fine leaved perennial grasses such as Red Fescue, and Bents can dominate with Ling Heather, Bell Heather, Creeping Willow and a variety of broad-leaved herbs including Eyebrights, Yarrow, Kidney Vetch, Ribwort Plantain, Hawkbits and Wild Thyme. Example Buckroney Dunes, Co. Wicklow

The distribution of heathlands in Ireland. (Adapted from Royal Irish Academy Atlas of Ireland published in 1979).

4 WET HEATH
Wet heath occurs on peaty soils and shallow wet peats that typically have an average depth of 15-50cm. Wet heath can occur in upland and lowland areas and is widespread on the lower slopes of hills and mountains that are either too dry or too steep for deep peat accumulation. It can form mosaics with blanket bog and dry siliceous heath. Wet heath is dominated by Ling Heather and Cross-leaved Heath or by Purple Moor Grass and sedges. Other common species include Bell Heather, Crowberry, Deer Sedge, Heath Rush and Green-ribbed Sedge. Moss and lichen cover is high and includes Hylocomnium splendens, Dicranum scoparium, Rhytidiadelphus loreus, Hairy Cap Moss and Sphagnum species such as S. papillosum, S. subnitens and S. capillifolium. Wet heath differs from dry siliceous heath in that Cross-leaved Heath, Purple Moor Grass and Deer Sedge are Abundant. Example: Slieve Beagh, Co's Monaghan, Tyrone and Fermanagh.

5 MONTANE HEATH
Montane heath has a substantial cover of dwarf shrubs and/or mosses and occurs at high altitude on mountains and in other very exposed locations in the uplands or on the coast. Montane heath is usually associated with shallow mineral soils or peats that are eroding and unstable. It can also be found on areas of loose rock and coarse sediment on mountain tops and ridges. High rainfall and humidity mean that montane heath is kept very wet even if soils are free-draining or rocky. The vegetation which should cover at least 50% of the terrain, is characterised by stunted and wind-contoured dwarf shrubs such as Crowberry, Ling Heather and Bearberry and or prostrate shrubs such as Dwarf Willow and Juniper. Montane heath may also be dominated by mosses. Low growing grasses also occur in the vegetation such as Wavy Hair Grass, Viviparous Fescue and Mat Grass. Heath Rush, Stiff Sedge, Heath Bedstraw, Sheep's Sorrel, Club moss, Silver-haired moss, and Hairy Cap Moss also occur. Montane heath may also have extensive carpets of lichens. Example Mweelrea Sheffrey Erriff Heath, Co. Mayo.

FLORA OF HEATHLANDS
The most abundant and conspicuous shrubby species on heathlands are members of the heath family of plants, particularly Ling Heather. Bell Heather is common and Cross-leaved Heath occurs in the wetter places. Gorse (furze) and Broom, both members of the pea family, are also common and in some places the ground is covered with Bilberry, Cranberry and Crowberry. In dry areas Bracken Fern often dominates the scene. Bearded and Matchstick Lichens carpet the ground between the heather bushes. Although grasses are not the dominant plants many species are found scattered throughout heathland areas and include Sheep's Fescue, Wavy Hair-grass, Common Bent and, in the wetter heathlands Purple Moor Grass. Typical herbaceous plants include Sheep's Sorrel, Heath Bedstraw, Tormentil, Heath Speedwell and Slender St John's Wort. Mosses can form dense green mats in pockets between the shrubs. The bright yellow green tufts of Dicranum scoparium can easily be seen as can Hairy Cap Moss which looks like a minute fir tree. Beneath the heather, Hypnum cupressiforme forms dense pale green mats. In wetter areas of heathlands Round-leaved Sundew, Single-headed Bog Cotton, Bog Asphodel, Marsh St John's Wort and White Beak Sedge also occur.

TOP 10 HEATHLAND PLANTS

Bell Heather, Bent Grass, Blueberry, Bracken, Cross-leaved Heath, Gorse (Furze or Whin), Hairy Cap Moss, Heath Spotted Orchid, Ling Heather, Purple Moor Grass

Lichen       Bilberry           Bracken Fern             Hairy Cap Moss

Heather on Heathlands The most common heathland plant is Heather or Ling, a plant that needs only the smallest amounts of water and minerals to survive. Ling Heather is an evergreen dwarf shrub with numerous small overlapping ridged leaves lined up in two opposite rows on the numerous branches. The pale pink flowers appear from August to September and are distinctive from other heath species because the calyx is longer and the same colour as the corolla. It is pollinated by insects, especially Thrips. A Heather plant can live for up to 30 years, but seedlings can only germinate in bare soil. So unless the other vegetation is removed by fire or grazing animals, Heather can eventually disappear from a heathland. Adult Red Grouse are dependent on Ling Heather for food and shelter. The Emperor Moth caterpillar is also dependent on Heather for food. The brown silk cocoons of this moth are often seen attached to the heather stems.

FAUNA OF HEATHLANDS
Heathlands are rich in invertebrates. Many species require warm and sunny conditions and favour south-facing slopes. Patches of bare ground, where there is no vegetation cover, are important to some groups, and the occurrence of boggy ground greatly increases the number of those species which typically breed in damp soil. About half the species of dragonfly that occur in Ireland can be found in heathland including the Large Red Damselfly, Common Blue Damselfly, Hairy Dragonfly, Common Hawker, Four Spotted Chaser and the Ruddy Darter. They particularly need the small pools for their eggs and larvae. Heathlands are an important habitat for butterflies and moths such as the Green Hairstreak, Emperor Moth, Oak Eggar and Fox Moth.

Grasshoppers which are more usually heard than seen, are widespread on heathland. In wet heaths the Large Marsh Grasshopper may be seen. Bees and wasps are also abundant. The bare ground is particularly important for Solitary Wasps to dig their nests. The Green Tiger Beetle is another striking insect of heathlands.

Heathlands are rich in spiders as can be seen from the dew-laden webs of certain species, blanketing bushes such as Gorse, in the early morning.

The vast array of insects of heathlands can support a low density Pygmy Shrew population. Ireland's only reptile the Viviparous Lizard occurs on heathlands.

Viviparous Lizard       Orb Spider           Emperor Moth

BIRDS OF HEATHLANDS
Insectivorous bird species such as Whinchat, Stonechat, Ring Ouzel, Sedge Warbler, Meadow Pipit and Whitethroat take advantage of the rich insect fauna associated with heathlands in the breeding season.

The air over a heath is often filled with the songs of the Meadow Pipit and skylark. Meadow Pipits nest in Purple Moor Grass and regularly play host to Cuckoos on the heathland.

The distinctive tapping of Stonechats and the call of the Cuckoo is frequently heard in summer. Whitethroats regularly nest on Gorse and in scrub areas. The male's plumage is particularly obvious in summer, with a grey cap, white throat and reddish wings. They feed on insects and their larvae, spiders and fruit. The Stonechat may be seen perching prominently on most heaths in summer atop gorse bushes, constantly flicking its tail and flinching its wings in an upright stance. It is distinguished from the Whinchat by its tiny size and all dark tail which lacks any white feathers. A ground nester from late March to July, it lays 5-6 pale blue eggs which are incubated by the female. Whinchats are April to October summer visitors to heathlands.

From late May to August go to wooded heathland edges at dusk to hear the monotonous churring of the Nightjar. The Red Grouse glides low across the heathland to an accompaniment of clucking alarm calls. The chicks are fed on a variety of insects including flies, beetles and spiders, but as the birds get older, their diet consists almost entirely of young Heather shoots, Bilberry leaves and blue berries. Grouse also build their nests in mature Heather bushes.

Five notable birds of prey feed in heathlands during the breeding season. These are the Hen Harrier, Merlin, Buzzard, Kestrel and Peregrine. The Merlin is Ireland's smallest bird of prey with daring acrobatic flight while hunting Pipits on the heathland. Hen Harriers are winter visitors to heathlands hunting for mammals and birds especially from October to March.

HEATHLAND BIRDS
Buzzard, Chough, Cuckoo, Golden PLover, Hen Harrier, Kestret, Meadow Pipit, Merlin, Nightjar, Peregrine Falcon, Red Grouse, Ring Ouzel, Sedge Warbler, Skylark, Stonechat, Twite, Whinchat, Whitethroat.

Stonechat    Skylark (Left) Meadow Pipit (Right)       Hen Harrier   Merlin

THREATS TO HEATHLANDS

Habitat loss is the main threat to heathland mainly from land reclamation, tree planting, excessive burning, invasion by pine and birch, motor bike scrambling, horse riding and Bracken fern invasion. On the poor soils of heathlands, plants take a long time to re-establish ground cover following damage.

Unwise management of heathlands can cause major changes in the habitat. Fire was traditionally used to maintain a mosaic of heather of different ages which allows for the traditional plants of heathlands to establish themselves. However the repeated burning of the heath helps the spread of Bracken which can dominate the heathland because few other plants can grow near its poisonous roots.

One of the main threats is from the fragmentation of the heathland. There is a direct link between the size of the heath and the number of species present - smaller heaths having far fewer species of plants and animals. The large expanses of heathland are being broken up by reclamation for other land uses. Now only small patches of the heathlands remain, so that if an area is damaged, for example by fire, the plants and animals cannot recolonise it because the fragments are many kilometres apart.

CONSERVING HEATHLANDS

The Irish Peatland Conservation Council is the non governmental organisation working to conserve heathlands and other peatland habitats. We have compiled a list of heathlands of conservation importance in Ireland. We are working with the National Parks and Wildlife Service to have a national survey of these sites undertaken with a view to conserving a representative sample of them as Special Areas of Conservation and Natural Heritage Areas for future generations to enjoy.

HEATHLANDS IN PRINT

A Guide to Habitats in Ireland by Julie A. Fossitt, published by the Heritage Council, Kilkenny, Ireland 2000.
Heathlands by Chris Packham, published by Collins, London 1989.
Ireland A Natural History by David Cabot, published by HarperCollins, London 1999.
Wild Wicklow by Richard Nairn and Miriam Crowley, published by Town House, Dublin 1998.

HEATHLANDS ON THE WEB

Further information on UK heathlands can be found at www.english-nature.org.uk/heathlands