Title
West Irish-west British hyperoceanic, moss- and lichen-rich sessile oak forests (Quercus petraea) with Betula pubescens, Ilex aquifolium, Dryopteris aemula, Luzula sylvatica, Hymenophyllum tunbrigense, Hymenophyllum wilsonii, Saccogyna viticulosa, Plagiochila spinulosa
Geographical distribution
Country/territory
Southwest and northwest Ireland: Kerry; Great Britain: northwest Wales, north England (Lake District) and west Scotland
area frequency
24 polygons.
Scientific names of main plant communities and their most common synonyms (with author citation)
Blechno spicant-Quercetum petraeae Braun-Blanquet & Tüxen 1952, especially the subassociations isothecietosum myosuroidis Braun-Blanquet & Tüxen 1952; W17 Quercus petraea-Betula pubescens-Dicranum majus woodland, Isothecium myosuroides-Diplophyllum albicans sub-community (Rodwell 1991).
Structural feature of the main community(ies) (layers, life-forms, etc.)
Quercus petraea dominates in the 15-20 m high tree layer, and there is scattered Betula pubescens. The well-developed shrub layer consists of Ilex aquifolium, Sorbus aucuparia and the naturalized Rhododendron ponticum (often thicket forming). In the herb layer dwarf shrubs such as Vaccinium myrtillus and Calluna vulgaris as well as Pteridium aquilinum are characteristic. They form a mosaic with grasses, herbs and other ferns. Opulent and species-rich moss layer with remarkable mosses, liverworts, lichens as well as epiphytic communities.
Dominant and most frequent species in different layers
Tree layer
Quercus petraea, (Betula pubescens)
Shrub layer
Ilex aquifolium, Sorbus aucuparia, locally Rhododendron ponticum (introduced)
Lianas
Hedera helix, Lonicera periclymenum
Herb layer
Pteridium aquilinum, Anthoxanthum odoratum, Agrostis capillaris, Deschampsia flexuosa, Calluna vulgaris, Solidago virgaurea, Potentilla erecta, Melampyrum pratense, Molinia caerulea, Dryopteris dilatata, Hedera helix, Teucrium scorodonia, Galium saxatile, Luzula sylvatica, Blechnum spicant, Oreopteris limbosperma, Saxifraga spathularis, Dryopteris aemula, Hymenophyllum tunbrigense, Hymenophyllum wilsonii, Vaccinium myrtillus, Oxalis acetosella, Polypodium vulgare, Athyrium filix-femina, Agrostis canina
Moss layer (incl. lichens)
Polytrichum formosum, Dicranum scoparium, Hypnum cupressiforme, Dicranella heteromalla, Pleurozium schreberi, Leucobryum glaucum, Scleropodium purum, Rhytidiadelphus squarrosus, Thuidium tamariscinum, Thuidium delicatulum, Eurhynchium striatum, Hylocomium brevirostre, Hylocomium splendens, Rhytidiadelphus loreus, Dicranum majus, Plagiothecium undulatum, Bazzania trilobata, Sphagnum quinquefarium, Mylia taylorii, Dicranodontium denudatum, Hookeria lucens, Hylocomium umbratum, Mnium hornum, Isothecium myosuroides, Campylopus flexuosus, Pseudotaxiphyllum elegans, Diplophyllum albicans, Lepidozia reptans, Calypogeia arguta, Calypogeia muelleriana, Cephalozia bicuspidata, Scapania nemorea, Scapania umbrosa, Marsupella emarginata, Gymnocolea inflata, Microlejeunea ulicina, Nowellia curvifolia, Harpanthus scutatus, Riccardia palmata, Heterocladium heteropterum, Hyocomium armoricum, Ptychomitrium polyphyllum, Dicranum scottianum, Campylopus atrovirens, Anastrepta orcadensis, Breutelia chrysocoma, Herbertus aduncus, Lepidozia cupressina, Lepidozia pearsonii, Plagiochila atlantica, Saccogyna viticulosa, Scapania gracilis, Sematophyllum demissum, Sematophyllum micans, Telaranea nematodes; laurel forest mosses: Drepanolejeunea hamatifolia, Frullania teneriffae, Lejeunea flava, Lophocolea fragrans, Plagiochila exigua, Plagiochila bifaria, Plagiochila punctata, Plagiochila spinulosa
Diagnostically important species
Quercus petraea, Betula pubescens; Ilex aquifolium; Vaccinium myrtillus, Blechnum spicant, Hymenophyllum tunbrigense, Campylopus flexuosus, Scapania gracilis, Scapania umbrosa, Bazzania trilobata, Bazzania tricrenata, Plagiochila punctata, Plagiochila exigua, Plagiochila spinulosa, Plagiochila bifaria, Plagiochila atlantica, Dicranum scottianum, Harpanthus scutatus, Jamesoniella autumnalis, Sematophyllum micans, Sematophyllum demissum, Tritomaria exsecta, Anastrepta orcadensis, Jungermannia gracillima
Ecological variants
---
Geographical variants (geogr. differential species)
In Ireland the unit contains extremely oceanic species (e.g. Saxifraga hirsuta, Euphorbia hyberna) and Mediterranean species (Arbutus unedo) of which some are absent from Great Britain. In Great Britain there is also Betula pubescens subsp. carpatica.
Natural accompanying vegetation (most important units in complex with the name giving mapping unit, scientific names)
Zonings or mosaics with oak-ash-forests on more base-rich soils, Alno-Ulmion forests on wetter, base-rich soils, Betulion pubescentis forests on wetter, base-poor soils as well as blanket and raised bogs on peat.
Adjoining climax and permanent vegetation (with numbers of mapping units)
birch forests (C16), pine forests (D50), coastal and mountain heaths (E5), coastal heaths (E6, E11), acidophilous oak forests (F2), oak-ash forests (F28, F32), dune vegetation (P6), salt vegetation (P19), blanket and raised bogs (S5, S6, S7, S8), brown mires (S24), alluvial and moist forests (U7, U23).
Land use, substitute communities
forestry (substitute communities, plantations of economic tree-species, scrub)
Low forests (particularly oak), plantations of softwoods (especially foreign), secondary succession stages often dominated by birches.
grassland (meadows, pastures, herb-rich communities)
Extensive pasturing (today almost always sheep, formerly rather cattle and various other grazing animals); Juncus rich Molinietalia grasslands altered by melioration, fertilization and resowing in the direction of Nardo-Galion and Cynosurion grassland. Burning off and extensive grazing has encouraged the development of heaths as substitute vegetation; dense Pteridium aquilinum dominant stands frequently act as a replacement community for forest on deeper soils.
arable land (characteristic weed communities)
No details
settlements (typical ruderal vegetation)
In the environs of small settlements and isolated agricultural holdings at the edges of the highlands there is Ulici-Sarothamnion scrub as well as Chenopodietea, Artemisietea, Stellarietea and Plantaginetea weed communities.
Site conditions of the mapping unit
Landscape type, geomorphology
Frequently steep silicate mountains, locally also rocky gorges/ravines
Altitudinal belt and/or altitudinal range
colline to submontane; mostly below 300 m
Geology (bedrock)
Siliceous rocks: sandstone, slate and metamorphic rocks (Palaeozoic, Precambrian)
soil type, also the depth of fine textured earth (soil), stone content; (international nomenclature)
ranker, acidic and podzolized brown soils, podzoles with mull-like mor or raw humus layers; (dystric cambisols; placic podzols; humic gleysols)
soil moisture, water balance
fresh to moist (often moist by high precipitation)
soil fertility
oligotrophic, oligo-mesotrophic (with partly low content in phosphate)
Climate incl. local climate
climate type (following Walter & Lieth)
V(VI)1, VI3b, VI4, VI(V)1
average annual temperature
8-11 EC
average annual precipitation
1200-2400 mm
average temperature of the warmest month
July 14-16 EC
average temperature of the coldest month
February 3-6 EC
local climate or other climatic peculiarities
The mild climate, mostly free of frosts, frequent precipitation (often above 250 days of rain) and high air moisture contribute to the development of opulent bryophyte and lichen communities. The topographical position (e. g. in gorges) even intensifies shading and air moisture.
Importance for nature protection
Present state and development trend of natural vegetation (degree of endangerment)
These are currently only preserved as small and isolated stands in agricultural landscapes as a rule.
endangered communities, species worthy of protection in natural vegetation
Typical cryptogame communities with many rare oceanic species are especially sensitive: Scapania gracilis, Scapania umbrosa, Bazzania trilobata, Bazzania tricrenata, Plagiochila punctata, Plagiochila spinulosa, Plagiochila bifaria, Plagiochila atlantica, Dicranum scottianum, Harpanthus scutatus, Jamesoniella autumnalis, Sematophyllum micans, Sematophyllum demissum, Tritomaria exsecta, Anastrepta orcadensis, Jungermannia gracillima. Trichomanes speciosum is a protected species in Ireland.
causes of endangerment
Grazing and trampling of the vegetation by livestock and red deer, clearings, heavy recreational use, spreading of Rhododendron ponticum, plundering by bryologists !
required measures for protection and restitution
Protection from grazing and game browsing, and in areas also from visitors; clearing of rhododendron stands.
Localities of representative stands (loci typici) with state of protection
of the natural vegetation
Ireland: Uragh Wood, Killarney Woods, Co. Kerry; Glengariff Woods, Co. Cork; Derryclare Wood, Co. Galway; Glenveagh Woods, Co. Donegal. (all nature reserves); Great Britain: Coedydd Maentwrog, Coed Gannllwyd, Coed Crafnant, Coed Rheidol, Loch Sunart Woodlands, Loch Maree.
of characteristic substitute communities worthy of protection
Partly in regions mentioned above.
Most important references (author, year)
Birks 1973; Birse 1980; Birse 1984; Birse & Robertson 1976; Braun-Blanquet & Tüxen 1952; Crampton 1911; Kelly 1975; Kelly 1981; Kelly & Moore 1975; Klötzli 1970; McVean & Ratcliffe 1962; Peterken 1981; Rodwell (Ed.) 1991a; Tittensor & Steele 1971
Compiled by
J.R. Cross; J.S. Rodwell, completed by J. Pallas
