Included here is a zone that extends from the northwest and northern parts of the Iberian Peninsula (including the Pyrenees) north to include Great Britain and Ireland and on to the western shores of Norway as far north as the islands of Hitra and Froga. On the European mainland the Armorican Massif, the Aquitanian and Parisian Basins, the Central Massif, and most of the German lowlands are included.

Atlantic European Chalk Beech Woods

Dominated by Fagus sylvatica (beech) these woods tend to be confined to the more shallow, porous soils. They are particularly well established in northwest and central France, southeast England, and Belgium, but also occur as far north as southern Sweden and in the south they occur in the montane regions of northern Spain. Species composition varies from place to place, but on the chalk soils of England, Fagus sylvatica is usually accompanied by Fraxinus excelsior (ash), Prunus avium and Sorbus aria as the main canopy trees, while lower tree levels typically include Ilex aquifolium and Taxus buccata. The low sub-canopy light levels (sometimes down to 2% of incoming radiation) together with heavy leaf litter that is slow to decompose, results in a poor shrub layer and poor but often interesting field layer. Typical shrubs include Buxus sempervirens, Corylus avellana, Euonymus europaeus and Sambucus nigra. In southern England the characteristic field layer includes Aquilegia vulgaris, Sanicula europaea, Helleborus viridis, Polygonatum multiflorum, the orchids Epipactis helleborina, Cephalanthera damasonium, Neottia nidus-avis and the parasite Monotropa hypopitys. In France and Belgium other field layer species may include Helleborus foetidus, Polygonatum odoratum and Vincetoxicum officinale.

Atlantic European Limestone Ash Woods

Woodlands dominated by Fraxinus excelsior (ash) are mainly found on limestone or scree in areas north of Atlantic European Beech Woods, while woodlands dominated by the narrow-leaved ash (Fraxinus angustifolia) occur in northern coastal regions of Spain. In England other canopy trees include Sorbus aria, Taxus buccata, Tilia cordata and Ulmus glabra. These are generally open woodlands so have well-developed scrub and field layers. Typical shrubs include Cornus sanquinea, Corylus avellana, Crataegus monogyna, Euonymus europaeus, Rhamnus catharticus, Sambucus nigra and Viburnum lantana. The field layer can be particularly species-rich. Examples include Allium ursinum, Adoxa moschatellina, Aquilegia vulgaris, Campanula latifolia, Galium odoratum, Platanthera chlorantha, while in more northern areas Polemonium caeruleum and Trollius europaeus may be present. Typical field layer species in Fraxinus angustifolia woodland include Ajuga reptans, Euphorbia amygdaloides, Primula vulgaris, Stachys officinalis and the fern Athyrium filix-femina. 

Atlantic European Fens

These alkaline habitats are usualy dominated by various sedges and rushes. Characteristic species include Cladium mariscus, Carex flacca, Carex nigra, Schoenus nigricans, Juncus articulatus and Juncus subnodulosus. They also include a variety of distinctive herbaceous species like Caltha palustris, Epipactis palustris, Dactylorhiza incarnata, Filipendula ulmaria, Lathyrus palustris, Lychnis flos-cuculi, Lysimachia vulgaris, Lythrum salicaria, Peucedanum palustre and Thalictrum flavum. Another type of mire is the so-called rush pasture typically dominated by Juncus effuses or Juncus acutiflorus. An interesting endemic possibly encountered in rush pasture is the stange whorled caraway Carum verticillatum (Apiaceae), although it can also be found in Molinia mire

References

Polunin, O. & Walters, M. 1985. A guide to the vegetation of Britain and Europe. Oxford University Press.