Woodland description

Acidic wet woodland occurs throughout Scotland, though most woods are found in the uplands and upland fringes, in areas of impeded drainage, usually on peaty or peaty gley soils that range from wet to very wet. It also occurs on wooded bogs in the lowlands. 

It is generally dominated by downy birch but some woods, especially in the west, may be dominated by thickets of eared or grey willows.

Most pinewoods are included in the ‘acidic dry’ woodland type but Scots pine growing in bogs are included in ‘acidic wet’ woodland. These bog woodlands have an open structure, usually with stunted trees and a typical mire field layer flora. 

Ground flora

The ground flora will be determined by soil conditions, especially wetness, and grazing history. Species may include:

• Heaths: Heather and cross-leaved heath are typical components of wooded bogs. 
• Herbs: Herbs are generally poorly represented, though tormentil, heath bedstraw and marsh violet occur widely.   
• Ferns, grasses and rushes: Purple moor-grass can be dominant in western woods. Wavy hair-grass, creeping soft-grass, bent grasses and Yorkshire fog may be present. Rushes, either soft rush or sharp-flowered rush, may be locally dominant. Ferns are not usually abundant but broad buckler fern may be frequent in drier woods.
• Lower plants: Mosses can be abundant, especially in the wettest woods where Sphagnum species can dominate the field layer. Polytrichum species may form conspicuous patches. 

Forage potential

Generally, acidic wet woodland has low forage potential, especially where the ground flora is dominated by mosses. The greatest productivity can be expected from open and relatively dry woodland where there is a component of palatable grasses and ferns in the field layer.

See also:

• Possible biodiversity objectives for acidic wet woodland
• Guidance in assessing woodland structure and condition
• Estimates of potential forage availability