rainfall (>900 mm per year). Ash is the major and often dominant tree species, although oak, wych elm, cherry, birch, or small-leaved lime may be more abundant locally. Hazel is very common in the understorey, and in some places may form the canopy. Yew can be present in small groves and alder may occur where there are transitions to wet woodland.
Upland mixed ash woods are amongst the richest habitats for wildlife in the uplands, notable for displays of bluebells, primroses and wild garlic, and supporting a rich invertebrate fauna.
Priority bird species using this habitat include wood warbler and redstart where the shrub and field layer is sparse, and tree pipit in open areas.
Wet woodland Wet woodlands occur on poorly drained or seasonally wet soils, and usually have alder, willow or birch as the dominant tree species. In Wales, wet woodlands occur in three main situations:
on wetlands such as fens, bogs, swamps,
wet pasture, and lake margins
Figure 5 Distribution of records for mixed ash wood summarised from Phase II Surveys of Welsh woodlands (CCW 2003).
Woodland types in Wales
on upland waterlogged plateau or on wet areas on valley sides where alder is the dominant species
on lowland floodplains and river edges with willow and alder as the main species.
Priority birds are willow tits, lesser redpoll and woodcock.
Lowland beech and yew woodland Lowland beech and yew woodland spans a variety of vegetation types reflecting differences in soil and topographical conditions, but the single defining character is the abundance and often dominance of beech. Beech can grow on both acidic and calcareous soils, although its association with yew tends to be most marked on calcareous sites.
The native range of beech in Wales is generally accepted to include Gwent and eastern Glamorgan and possibly on the southern fringes of the Brecon Beacons National Park. Beech is also common as a planted or naturalised tree throughout Wales. Yew woodland occurs rarely in north-east and south-east Wales.
Figure 6 Distribution of records for wet woodland summarised from Phase II Surveys of Welsh woodlands (CCW 2003).