The Belfast Hills contain a range of woodland habitats, reminders of when Belfast would have been surrounded by forests. The broadleaf woodlands which remain are covered in a fantastic variety of woodland plants such as bluebell, violet, wood anemone and wood sorrel. The build up of fallen leaves over the years means that deciduous woods produce rich, fertile soil and considerable harvests of berries and nuts – all good news for insects, birds, bats, hedgehogs, fungi and our remaining red squirrels. More recently planted coniferous woodlands may be seen at Glenside Community Woodland.
Parts of Carnmoney Hill and Cave Hill have been classified as ‘long established woodland’, while the upper parts of Colin Glen Forest Park have been classed as possibly being even older ‘ancient woodland’ (Woodland Trust Inventory Report 2007). Mixed deciduous woodland is found at Colin Glen Forest Park and Carnmoney Hill. Mixed ash woodland occurs in areas such as Cave Hill Country Park.
Very steep and stony areas, for example river valleys, are one of the few areas of ground that have been rarely grazed, planted or built on. One use for these steep areas would have been hazel coppice, cut down every few years for fencing, wattle and daub or firewood. Hazelwood, above Belfast Zoo, is an example of this.
Within the hills are numerous unplanned and abandoned corners, and strips where grassland has been colonised by shrubs and small trees, which is classed as ‘scrub’. The mixture of rough grass, thickets and bushes of blackthorn and hawthorn, make a wonderful place for song birds such as grasshopper warblers, sedge warblers and willow warblers to nest and feed in.
Hedges dominate much of the lower areas of the Belfast Hills. They can be extremely valuable for biodiversity when managed appropriately. Hedges act as wildlife corridors allowing animals to move safely to new feeding sites, often carrying plant seeds as they go. Their autumn flush of fruit such as haws, sloes, elderberries and hips are vital to many over-wintering birds such as redwings and fieldfares that use the hedges of the hills to skirt along the edges of Belfast and up the Lagan Valley. Spreading more slowly along these vital corridors are woodland plants such as primroses, violets and wild strawberries.