Mixed Ashwood is a broad-leaved, semi-natural habitat that constitutes one of the main woodland habitats in Northern Ireland. Many of these habitats are ancient, with ash Fraxinus excelsior as the dominant species.

Key Characteristics

Site: From steep limestone scarps & sprees to more gentle slopes
Soil: Base-rich, variable depth, moderately free draining/poorly drained acid soils, flush of nutrients
Main species: Ash
Other species: Rowan, oak, elm, birch, yew, hazel, small-leaved lime
UK: 67,500 ha
NI: 3,430 ha (<1,000 ha pre-1900)

Habitat Description

  • Mixed Ashwoods grow on base-rich soils, which are naturally productive.
  • Although ash is the major tree species, there is an abundant mix of different species such as rowan, oak, elm, birch, yew, hazel & small-leaved lime. In Northern Ireland there is dominance of ash & hazel, often with goat willow Salix caprea. Where there is transition to wet woodland, alder may be present. Non-native sycamore Acer pseudoplatanus & beech Fagus sylvatica colonise some woods.
  • Due to the fertile, alkaline nature of the soil, mixed ashwoods support rich & colourful ground flora including wood anemone, primrose, wood-sorrel, herb-robert, wild strawberry, guilder rose, holly, wild garlic & bluebell.
  • Plant communities, in relation to the NVC of Great Britain, include W8 Fraxinus excelsior-Acer campestre-Mercurialis perennis woodland, W9 Fraxinus excelsior-Sorbus aucuparia-Mercurialis perennis with W13 Taxus baccata. Rare woodland flower species can occur in upland ashwoods, such as dark red helleborine Epipactis atrorubens, autumn crocus Colchicum
  • Various rare native trees are also supported, including whitebeams (Sorbus spp.) & the large-leaved lime Tilia platyphyllos.

Current Status in UK & Northern Ireland

  • Precise data on the total extent of mixed ashwood in the UK is lacking but it is estimated at 67,500 ha (JNCC, 2001).
  • In NI mixed ashwood occur on base-rich basalts of County Antrim & limestone of Counties Fermanagh, Armagh, Down & Tyrone.
  • An estimated 3,430 ha in NI is occupied by mixed ashwood but this figure incorporates all mixed ashwoods, regardless of age & condition. The condition of mixed ashwoods in NI is currently unknown. A large proportion of the ash trees are immature & non-indigenous species such as sycamore & beech may dominate, yet native ground flora may remain.
  • Approximately 3,300 ha are privately owned & 130 ha are under public ownership (based on Graham, 1975). The latter figure is an underestimate as it excludes 2,700 ha of woodland that has been classified by the Forest Service as planted conservation, in which planted woodland areas include semi-natural woodland habitats. Of this mixed ashwood area, a large proportion of the ash are immature.
  • Mixed ashwoods in NI are generally unmanaged, often used for grazing & shelter by livestock.
  • They are under threat from physical damage by livestock, habitat loss & fragmentation, air pollution, climate change & nutrient enrichment. Invasion by non-native species such as sycamore or beech & ground flora species such as Japanese knotweed & snowberry may alter the woodland structure.

Designated Sites

  • Aghanloo Wood
  • Banagher Glen
  • Black Burn
  • Cleggan Valley
  • Glenariff
  • Glenarm Woods
  • Glen Burn
  • Straidkilly

Further Information