Title
Irish-English hazel-ash forests (Fraxinus excelsior, Corylus avellana) with Asplenium trichomanes, Sesleria albicans and rich in bryophytes on shallow calcareous soils
Geographical distribution
Country/territory
Ireland: northern and western central lowland; Great Britain: southeast Cumbria, central Pennines
area frequency
10 polygons.
Scientific names of main plant communities and their most common synonyms (with author citation)
Corylo-Fraxinetum neckerotosum Kelly & Kirby 1982; Fraxinus excelsior-Acer campestre-Mercurialis perennis woodland, Geranium and Teucrium sub-communities (W8 p.p.).
Structural feature of the main community(ies) (layers, life-forms, etc.)
Four-layered forest stands with a low (8-15 m) interspersed tree layer primarily of Fraxinus excelsior and an often dense shrub layer primarily of Corylus avellana with Crataegus monogyna, Prunus spinosa and other species. On extreme sites the scrub only reaches 2 m in height. The herb layer is usually weakly developed, but species-rich and without dominating species, whereby ferns are frequent and conspicuous. The moss layer is usually luxuriantly developed and species-rich.
Dominant and most frequent species in different layers
Tree layer
Fraxinus excelsior (dominating), scattered Betula pubescens, Sorbus aucuparia, Malus sylvestris, Prunus avium, Ulmus glabra, Sorbus aria, Taxus baccata (locally dominating), introduced: Acer pseudoplatanus, Fagus sylvatica; in England additionally Acer campestre, Tilia cordata, Quercus robur, Quercus petraea
Shrub layer
Corylus avellana, Crataegus monogyna, Euonymus europaea, Ilex aquifolium, Prunus spinosa, Viburnum opulus
Lianas
Hedera helix, Lonicera periclymenum
Herb layer
Brachypodium sylvaticum, Potentilla sterilis, Fragaria vesca, Geranium robertianum, Primula acaulis, Oxalis acetosella, Viola riviniana, Arum maculatum, Sanicula europaea, Anemone nemorosa, Carex sylvatica, Dryopteris filix-mas, Polystichum setiferum, Asplenium scolopendrium, Asplenium trichomanes, Sesleria albicans, Rubus saxatilis; in England Mercurialis perennis
Moss layer (incl. lichens)
Eurhynchium striatum, Thamnobryum alopecurum, Thuidium tamariscinum, Rhytidiadelphus triquetrus, Hylocomium brevirostre, Ctenidium molluscum, Neckera complanata
Diagnostically important species
Fraxinus excelsior; Corylus avellana, locally Taxus baccata; Asplenium trichomanes, Sesleria albicans, Fissidens dubius, Neckera crispa, Marchesinia mackaii, Scapania aspera, Tortella tortuosa
Ecological variants
On deeper sites a form with Allium ursinum and Hyacinthoides non-scripta; on base-deficient sites with Hypericum pulchrum, Teucrium scorodonia, Solidago virgaurea.
Geographical variants (geogr. differential species)
Acer campestre, Tilia cordata and occasionally Tilia platyphyllos occur in Great Britain in the tree layer, with Mercurialis perennis often in the herb layer (lacking in Ireland).
Natural accompanying vegetation (most important units in complex with the name giving mapping unit, scientific names)
On deeper sites transitions to pedunculate oak-ash forests (F28), on wet sites to mixed alder ash forests (U23), in wet hollows tall sedge reed vegetation, lime-rich brown moss fens and occasionally raised bogs, on shallow elevations calcareous shortgrass meadows and scrub (F30).
Adjoining climax and permanent vegetation (with numbers of mapping units)
acidophilous oak forests (F1, F2), mixed oak-ash forests (F28, F30, F32), salt vegetation (P19), raised bogs (S5, S8), fens (S24), vegetation complex of degraded lowland-raised bogs (T7), alluvial and moist forests (U7, U23).
Land use, substitute communities
forestry (substitute communities, plantations of economic tree-species, scrub)
Selective timber usage, unsuitable for forestry, occasionally plantations of ash, larch or pine.
grassland (meadows, pastures, herb-rich communities)
Grassland, especially grazing, is the primary form of land usage: Asperulo-Seslerietum Br.-Bl. & Tx. 1952, Antennarietum hibernicae Br.-Bl. & Tx. 1952, Centaureo-Cynosuretum Br.-Bl. & Tx. 1952, Seslerio-Mesobromion Oberd. 1957.
arable land (characteristic weed communities)
Locally cereal (wheat, barley) and potato cultivation (in areas with deeper soils).
settlements (typical ruderal vegetation)
No details
Site conditions of the mapping unit
Landscape type, geomorphology
Undulating, often stony to rocky plains, karst landscapes in areas
Altitudinal belt and/or altitudinal range
lowland, colline; 0-200 m
Geology (bedrock)
limestone, without boulder covers of the ice-age (Carboniferous)
soil type, also the depth of fine textured earth (soil), stone content; (international nomenclature)
shallow rendzines, protorendzines, brown soils-rendzines; (rendzic leptosols; eutric and calcic cambisols)
soil texture
loamy, stone-rich to rocky
soil moisture, water balance
fresh to dry, locally temporarily overlogged, soil in general very water-permeable and quickly dessicating
soil reaction
neutral (pH ca. 6,9)
soil fertility
mesotrophic with a high lime content
Climate incl. local climate
climate type (following Walter & Lieth)
VI(V)1, VI(V)2
average annual temperature
8-10 EC
average annual precipitation
1000-1400 mm
average temperature of the warmest month
14-16 EC
average temperature of the coldest month
5-6 EC
local climate or other climatic peculiarities
Over 175 rain days per year, frequent formation of clouds and high air moisture.
Importance for nature protection
Present state and development trend of natural vegetation (degree of endangerment)
Only small areas with semi-natural forest are preserved, and mainly on steep slopes, but scrub on the other hand is relatively extensive. The semi-natural areas of this mapping unit are on the decline.
endangered communities, species worthy of protection in natural vegetation
Protected species: Gymnocarpium robertianum, Carex depauperata.
causes of endangerment
Timber use and clearing of scrub for agricultural use, grazing with sheep and cattle.
required measures for protection and restitution
Protection of semi-natural stands from transformation into agricultural land, tolerance of natural succession processes.
Localities of representative stands (loci typici) with state of protection
of the natural vegetation
Several representative stands stands in complex with fens and lakes present in reserves. Ireland: Coole-Garryland, Co. Galway; Dromore, Co. Clare; Slieve Carran, Co. Clare, nature reserves; Taxus baccata-stand in the Killarney National Park.
of characteristic substitute communities worthy of protection
Calcareous shortgrass meadows and rock heaths in reserves mentioned above.
Most important references (author, year)
Ivimey-Cook & Proctor 1966; Kelly & Kirby 1982; Kirby 1981; Rodwell (Ed.) 1991a
Compiled by
J.R. Cross
