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 Oak Woods

The dominant trees here are either Quercus petraea (sessile oak) or Quercus robur (pedunculate oak).  They tend to occur on the more acidic soils, but nevertheless, these woodlands are often the main climax vegetation. They can have well-developed shrub and ground layers. One of the more widespread and characteristic endemics of the field layer is Hyacinthoides non-scripta bluebell (Liliaceae), which may be so extensive as to create the illusion of a blue haze in places, especially in the United Kingdom. In some mixed oak woods both sessile and pedunculate oaks may occur together, but these are often on highly acidic soils and as a consequence have poorly developed shrub and field layers. In Sherwood Forest, England, for example, other trees in these mixed forests or woodlands include Betula pubescens, Malus sylvestris and Sorbus aucuparia. The sparse scrub layer typically includes Crataegus monogyna and Sambucus nigra, while the characteristic field layer species include bracken (Pteridium aquilinum) and grasses such as Agrostis capillarie, Descampsia flexuosa and Holcus lanatus.

Atlantic European Coastal Temperate Rain Forest

This type of forest is an extremely rare being confined to just seven regions of the world - the Pacific Northwest, the Valdivian forests of south-western South America, New Zealand, Tasmania, the north-eastern Atlantic (including the West Highlands of Scotland, Ireland, Norway and Iceland), south-western Japan and the eastern Black Sea. Because of its requirement for highly oceanic, humid conditions it is only found on the extreme western fringes of the BioProvince where annual rainfall exceeds 2000mm. These forests are some of the most complex and dynamic ecosystems on Earth supporting numerous mosses, lichens, ferns, fungi and invertebrates.  In fact, the biological diversity indices for some taxa (particularly invertebrates, bryophytes, fungi and soil organisms) compare with tropical rainforest. Also like tropical rainforests, their trees are often festooned with epiphytic species, but rather than orchids or bromeliads, the main species are usually lichens and mosses. Here the trees are typically dominated by Quercus petraea and Betula pubescens, but tree cover can be rather open and canopy height rarely exceeds about 20m. Other tree species tend to be scarce, but Corylus avellana and Sorbus aucuparia may form a scattered understorey. There is rarely a well-developed shrub layer but large ferns such as Pteridium aquilinum and Dryopteris dilitata may form sizeable stands, and there may be occasional dwarf ericoid shrubs such as Caluna vulgaris, Erica cinerea or Vaccinium myrtillus. The field layer may include grasses such as Agrostis capillaris, Anthoxanthum odoratum, Deschampsia flexuosa, Festuca ovina, Holcus mollis, and various herbaceous forbs like Anemone nemorosa, Galium saxatile, Hypericun pulchrum, Luzula pilosa, Luzula sylvatica, Melampyrum pratense, Oxalis acetosella, Potentilla erecta, Primula vulgaris, Stellaria holostea, Succisa pratense, Teucrium scorodonia, Veronica chamaedrys, Viola rivinianum, and the endemic Hyacinthoides non-scripta (Liliaceae). Ferns are also well represented and may include Athyrium filix-femina, Blechnum spicant, Dryopteris aemula, Gymnocarpium dryopteris or Thelypteris limbosperma. However, bryophytes often dominate the ground layer and may far exceeding vascular plants in their diversity and abundance. Some of the most frequent of these are Bazzania trilobata, Campylopus paradoxus, Dicrodontium denudatum, Diplophyllum albicans, Hylocomnium plendens, Hylocomnium umbratum, Isothecium myosuroides, Lepidozia reptans, Leucobryum glaucum, Plagiochila spinulosa, Polytrichum formosum, Pseudosleropodium purum, Rhytidiadelphus triquetrus, Saccogyna viticulosa, Scapania gracilis, Thuidium delicantulum and Thuidium tamariscinum.  Also many bryophyte species found here have distributions centred on the Atlantic zone – these so-called Atlantic species include Acrobolus wilsonii, Adelanthus decipiens, Aphanolejeunea microscopica, Colura calyptrifolia, Dicranum scottianum, Drepanolejeunea hamatifolia, Harpalejeunea ovata, Hyocomium flagellare, Lejeunea mandonii, Plagiochila tridenticulata, Radula carringtonii and Radula voluta.  In fact, several Atlantic species found in these woodlands, such as Plagiochila punctata and Plagiochila atlantica are endemic to the Atlantic European BioProvince. Bryophytes, together with lichens, also provide the largest number of epiphytic species. Tree trunks may be smothered in bryophyte species such as Hypnum mammilatum, Isothecium myosuroides and Scapania gracilis, while the smaller branches typically support Frullania tamarisci, Lejeunea ulicina, Ulota crispa and Ulota phyllanthus. Of the ferns Polypodium vulgare is commonly found as an epiphyte on oak, and the two filmy ferns, Hymenophyllum tunbrigense and H. wilsonii may be found among dripping mats of bryophytes.

Atlantic European 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 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 Wet Woods

Sometimes referred to as carr these woods of wet and waterlogged areas are usually dominated by Alnus glutinosa (alder), Betula pubescens (downy birch) and various willows such as the local endemic Salix phylicifolia [England, Scotland and Ireland] (Salicaceae). Carr occurs throughout the Atlantic European BioProvince from southwestern Norway to northern Spain. The often-rich shrub layer typically comprises Frangula alnus, Crataegus monogyna, Ligustrum vulgare, Rhamnus catharticus, Viburnum opulus and can include a number fruit bearing bushes such as Ribes nigrum (black currant), R. rubrum (red currant) and R. uva-crispa (gooseberry). Field layers tend to be species-poor but may include Eupatorium cannabinum, Filipendula ulmaria, Iris pseudocorus, Solanum dulcamera, Symphytum officinale, or the fern Thelypterus palustris. Field bindweed (Calystegia sepium) may also cover many of the shrubs. In northern Spain additional field layer species may include Scutellaria minor, Sibthorpia europaea and the royal fern Osmunda regalis.

References

Hodgetts, N. 1993. Atlantic bryophytes on the western seaboard. British Wildlife, 4: 287-295.

Moore, K. 1990. Where Is It and How Much is Left? The State of the Temperate Rainforest in British Columbia. Forest Planning Canada, 6:15.

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

Ratcliffe, D. A. 1968. An ecological account of the Atlantic bryophytes in the British Isles. New Phytologist, 67: 365-439.

Rhind, P. M. 2003. Comment: Britain’s contribution to global conservation and our coastal temperate rainforest.  British Wildlife, 15: 97-102.