Red List habitat classification > RLF - Heathland and scrub > RLF3.1g Corylus avellana scrub

Corylus avellana scrub

Quick facts

Red List habitat type code RLF3.1g
Threat status
Europe Least Concern
EU Least Concern
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)

Summary

This is permanent scrub dominated by Corylus avellana mostly typical of exposed coastal and upland situations with a humid Atlantic climate. The hazel forms a low canopy up to 3m tall, wind-shaped in more exposed situations, with multi-stemmed stools that are self-renewing by the production of new growth from the centre and slow clonal expansion. On shallower soils, stools tend to be more close-grown, with fewer thicker rigid stems and the scrub more shady; on deeper soils and in more sheltered situations, wider-spaced, multi-stemmed stools prevail with a lighter interior. Damage from winter storms also contributes to stem turnover and grazing/browsing can open up the canopy and prevent regeneration ultimately creating a parkland effect where older individual hazels can survive, sometimes acquiring a tree physiognomy.

The field layer varies according to the character of the soils which can be highly calcareous to slightly acid, shallow and skeletal to deeper and loamy and the often irregular topography favours complex mosaics with local instability of the surface. High precipitation usually maintains the soils in a moist condition, but local ground water seepage can further enhance wetness. The herb contingent is usually of the more Atlantic Carpinion type, more or less calcicolous according to the soil reaction, with an obvious vernal component in which Hyacinthoides non-scripta, Anemone nemorosa and Primula vulgaris often figure, and a sometimes luxuriant fern flora. Less limey soils can have a grassier flora with a summer cover of Pteridium aquilinum. Towards the north of the range, Trollius europaeus and Cirsium helenioides provide a distinctive phytogeographical element.

The cryptogam flora can be very rich and distinctive in less disturbed stands. Shadier and more humid interiors favour a luxuriant bryophyte flora over soil, rocks and the hazel stool bases, an ‘elfin’ aspect in which broader Atlantic and some specialist oceanic species are especially striking. The lichen flora is also particularly indicative of venerable stands with more light-demanding Graphidion species typical of smoother bark in less shady situations, Lobarion species on rougher bark and in shadier stands, both contingents including some internationally rare taxa. Hazel is ectomycorrhizal and a number of fungi can add to the floristic richness of the scrub.

The habitat described above occurs in Ireland and the United Kingdom, where it is found in locations where wind and shallow soils prevent the growth of trees. However, also in Central Europe permanent hazel scrub is found, in places where soil conditions prevent succession towards forest, for example on steep hillsides. Here also the scrub is in most cases growing on limestone, but occasionally also on other soil types. In this more continental region the herb layer consists of dry grassland and forest edge species, like Epipactis atrorubens, Campanula persicifolia, Brachypodium pinnatum and Melampyrum nemorosum. Such scrub communities are classified in the alliance Berberidion vulgaris.

Indicators of good quality:

  • Presence of at least some continuous cover of healthy multi-stemmed hazel bushes without any overtopping tree canopy
  • Diverse herb layer, often with complex mosaics over uneven topography
  • Rich and diverse cryptogam flora
  • Grazing and browsing at moderate levels at most
  • Absence of signs of coppicing
  • Absence of invading oceanic aliens e.g. Rhododendron ponticum.

Characteristic species
For full habitat description, please download the habitat factsheet.

Threat status

Synthesis of Red List assessment

Despite of its wide distribution, few countries reported any data on the type, which may be caused by some confusion about the definition and the difficulty in distinguishing between primary and secondary stands. However, the reported information shows a clear overall increase in surface extent and more-or-less stable trends in quantity and quality. These trends lead to the category Least Concern (LC).
EU
Red List Category Red List Criteria
Least Concern -
Europe
Red List Category Red List Criteria
Least Concern -

Confidence in the assessment

medium
Red List of habitat categories and criteria descriptions

Pressures and threats

  • Agriculture
    • Intensive grazing

Habitat restoration potential

In natural conditions the habitat can recover rather quickly from, for example winter storms, without human interventions but damage from intensive browsing and grazing can have slower recovery, with inhibited regeneration of the Corylus and loss of epiphytic cryptogams.

Trends in extent

Average current trend in quantity

Increasing Increasing
EU28 EU28+

Trends in quality

Average current trend in quality

Stable Stable
EU28 EU28+

Conservation and management needs

In good conditions no management is needed.

List of conservation and management needs

  • No measures
    • No measures needed for the conservation of the habitat/species

Distribution

For each habitat a distribution map was produced from a wide variety of sources indicating known and potential occurrences of the habitat in 10x10 km grids within Europe. Occurrences in grid cells were given in two classes: actual distribution from relatively reliable sources (surveys, expert knowledge), and potential distribution based on models or less reliable indicators. Please download the fact sheet to see the map.

Geographic occurrence and trends

EU28 Present or presence uncertain Current area of habitat (Km2) Recent trend in quantity (last 50 years) Recent trend in quality (last 50 years)
Czech Republic Present 05-Oct Decreasing Increasing
Germany Present unknown Stable Increasing
Slovakia Present 20 Stable Increasing
United Kingdom Present 15 Decreasing Stable
Ireland Present 100 Increasing Increasing
Belgium Uncertain - -
France mainland Uncertain - -
Italy mainland Uncertain - -
Poland Uncertain - -
Spain mainland Uncertain - -
EU28 + Present or presence uncertain Current area of habitat (Km2) Recent trend in quantity (last 50 years) Recent trend in quality (last 50 years)

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 4416400 668 125-175
EU28+ 687 125-175
AOO = the area occupied by a habitat measured in number of 10x10 km grid cells.
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).

Characteristic species

Not available

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
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