Errigal Glen ASSI

The area is of special scientific interest for oakwood and its nationally significant number of rare and notable woodland plants. This unique woodland plant assemblage is one of the richest in Northern Ireland and has been recognised by prominent botanists such as David Moore as early as1832, and Robert Lloyd Praeger in the late 19th and early 20^th centuries.
Today, the overall diversity of the woodland has been largely maintained with a number of rare species given special protection. Three species that have been recorded over the last 25 years include small cow-wheat, serrated wintergreen and Intermediate wintergreen. All have a restricted distribution throughout Northern Ireland and are listed as Red Data Book and Northern Ireland Priority Species.
Small cow-wheat is particularly scarce, recorded from only five other known locations in Northern Ireland since 1985 and together with Serrated wintergreen is further protected under Schedule 8 of the Wildlife (Northern Ireland) Order 1985.
In addition, yellow bird’s-nest orchid was recorded in the first half of the 20^th century. This species is also protected under Schedule 8 of the Wildlife (Northern Ireland) Order 1985 and is listed as a Red Data Book and Northern Ireland Priority Species. However, it has not been recorded for more than 60 years, although this may be a consequence of under recording. There are further historical records for bird’s-nest orchid, which is also protected under Schedule 8 of the Wildlife (Northern Ireland) Order 1985 and is listed in the Red Data Book.

Other notable species regularly recorded in Errigal Glen include bird cherry, which is also a Red Data Book Species, common wintergreen, toothwort and wood fescue.

The structure of the woodland has largely been shaped by past management and although it is described as oakwood, much of the canopy, particularly along the northern side of the glen is dominated by mature non-native trees. This reflects a period of past planting with species such as beech, sycamore and a range of conifers. By comparison, the woodland on the southern side of the river and a small area to the north east of the glen, is generally more natural in composition with a mature canopy dominated by sessile oak and downy birch. Other native canopy species include ash which is found in more base-rich conditions on the drier parts of the valley floor, and alder which is characteristic of the wettest parts.

The shrub layer is largely natural and consists of hazel, which in the absence of mature trees frequently forms a dense, low canopy. Other shrub species include holly, rowan, hawthorn and the notable bird cherry, with willow in wetter conditions. Where present, the field layer consists of a mixture of ferns including broad buckler-fern, male-fern and soft shield-fern, thickets of bramble, and locally in the most acidic conditions, the dwarf-shrub bilberry.
The herb layer of the glen slopes reflects the acidic nature of the wood and is dominated by great wood-rush, with bluebell locally prominent in damper conditions. On the more base-rich soils of the damp valley bottom, there is a notable increase in species richness. Commonly occurring species include wood anemone, water avens , Sanicle, lesser celandine, meadowsweet, enchanters nightshade, opposite-leaved golden-saxifrage and wood-sedge. Where the ground becomes waterlogged species such as marsh marigold, marsh hawk’s-beard, creeping buttercup and remote sedge are prominent.

The combination of local edaphic factors, particularly the humidifying influence of the river together with the range of living trees and dead wood, has resulted in a site rich in lichens and fungi. Fungi associated with trees are particularly well represented with ectomycorrhizal species such as birch milkcap, fiery milkcap and charcoal burner all being commonly recorded. A recent notable record was destroying angel associated with sessile oak.

The rare and notable species that occur in Errigal Glen today have been influenced by past management of the woodland and the variation of local edaphic conditions. Recent management of the wood has been one of minimal intervention. It is hoped that continued sensitive management of the woodland will ensure that the rich assemblage of species in Errigal Glen is maintained.

Errigal Glen also provides an important habitat for animals, including breeding birds and mammals. Mammals present include otter and badger.

Site Related Documents

Site map (.PDF 691Kb), Citation documents (.PDF160Kb) and Views about Management document (.PDF 61Kb)