Reference sessile oak states

There are three reference states for sessile oak woodland in Wales: ravine woods, mature ‘oceanic’ woods and ancient ‘continental’ woods. Each of these is described in the sections below.

Reference state 1 – Ravine woodlands

The most ‘natural’ reference state for sessile oakwoods in Wales are ravine woodlands in the more ‘oceanic’ west of the country. The best, and perhaps only, example is found at Devils Bridge in Ceredigion. Here the wood experiences high levels of humidity as a consequence of a waterfall running through the valley and remains unmanaged,…

Reference state 2 – Mature ‘Atlantic’ sessile oak woods

This ‘reference state’ is defined by mature stands of sessile oak woodland in an oceanic ‘high humidity’ location. It comprises trees with a mixed-age structure, i.e. not felled in the 20th Century, and has successful regeneration of oak saplings in the field layer under canopy gaps. This is achieved by ‘pulse grazing’, where animals are…

Reference state 3 – Mature ‘continental’ sessile oak woods

This reference state represents mixed age / ancient stands of sessile oak in central and eastern areas Wales, where the climate is more ‘continental’ and less humid. These woods tend to host less diverse bryophyte and lichen populations than the oceanic examples of the habitat, but the less intensively grazed examples can still support an…