Trees

Northern Ireland has fewer native species of tree than Britain, which in turn has fewer than continental Europe. At one time, much of Northern Ireland would have been covered with woodland dominated by oak, as is evident from the number of place names that include "derry," the anglicised version of "doire" which is the Irish word for oak.

Look out for the two different species of oak. In Northern Ireland, sessile oak, which has acorns on very short stalks, and longer-stalked leaves, is the commoner native species. Pedunculate oak, which has acorns on long stalks and shorter-stalked leaves, may also be native, but was widely planted. Oak was highly valued in the past. Its strong timber was used for building, and its bark for tanning leather, and its acorns for feeding pigs. This was so important that the Annals of Ulster make a specific record in years when there was a good crop of acorns.

Many of the oldest native woods now surviving in Northern Ireland are oak woods on acid upland soils, usually in areas where the steep slopes and poor soils were useless for farming.

Perhaps the second most important tree in days gone by was the hazel, now often viewed as a shrub, but valued in the past as a source of food (the nuts are high in fat and protein) and for the strong, flexible rods that can be cut regularly by coppicing and used for a wide range of purposes from wattle walls in building, to baskets and eel traps. Look out for the attractive catkins in spring.

Ash and wych elm in native woods are found on richer, alkaline soils, such as on the limestone of Fermanagh, or the basalt of the Antrim plateau and coast. Ash was also commonly planted, especially in hedgerows. Look at the base of an ash trunk, where the trunk curves into the root. Ash was traditionally used for making hurley sticks, this natural curve forming the curve of the stick. The timber is shock-resistant. Wych elm is the only native elm in Ireland and seems more resistant to Dutch elm disease than the introduced English elm.

Holly and rowan provide a welcome food source for birds with their brightly coloured berries. Alder, and several species of willow, tend to be found in wet woods, for instance around the shores of Lough Neagh and Lough Erne, and in damper valley bottoms elsewhere.

Less common are species such as yew, which has been widely planted but is less commonly seen in the wild, and juniper. Bird cherry, a relatively common species in England, is less common in Northern Ireland.

Many of the trees that you will see in easily accessible woods in Northern Ireland are not native species, but were introduced by people, and were widely planted on estates. Sycamore, beech, horse chestnut and sweet chestnut, and lime are all common features of parks and designed landscapes.

Scots pine was native in Ireland but died out, probably in mediaeval times. Now it tends to be seen as part of dense coniferous plantations, including other non-native species such as Sitka spruce. While these shady plantations can be damaging on ancient woodland sites, as they shade out the native flora, the seeds of Scots pine and other conifers do provide a good food source for the red squirrel.

Ancient and long-established woods, especially some of the parkland sites around big houses, are a good place to see ancient and veteran trees.