Red List habitat classification > RLG - Forests > RLG1.2a Alnus woodland on riparian and upland soils

Alnus woodland on riparian and upland soils

Quick facts

Red List habitat type code RLG1.2a
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

These are riparian and land-upheaval woodlands dominated by Alnus glutinosa and/or A. incana, and sometimes Fraxinus excelsior, typically without many softwood willows in the canopy, such woodland being assessed separately as G1.1 Temp and boreal softwood riparian woodland).  This habitat also differs from riparian woodlands of the middle and lower reaches of major European rivers, which is assessed separately as G1.2b Temperate and boreal hardwood riparian forest. The non-riverine subtype of this present habitat (corresponding to the original G1.B Non-riverine alder woodland) is typical of the Baltic coast, a sea with a low level of salinity.

The stands show varying degrees of soil moisture according to the frequency of flooding in mature river valleys, depth of water table, or proximity to the coast. Moister forms can also have some Salix fragilis, Betula pubescens and Prunus padus in the canopy with S. phylicifolia beneath;  in more mesic situations, Sorbus aucuparia can appear among the trees with Juniperus communis beneath.  Other shrubs include Crataegus monogyna, Ribes alpinum, R. spicatum, Rubus caesius, R. idaeus, S. triandra and Sambucus nigra.  The field layer can be quite species-rich, especially in moister situations, when more nutrient-demanding herbs such as Urtica dioica and Filipendula ulmaria may be abundant. Other herbs then include Valeriana sambucifolia, Angelica sylvestris, Deschampsia cespitosa, Calamagrostis canescens and C. purpurea.  More mesic stands have Milium effusum, Silene dioica, Rubus saxatilis and Poa nemoralis. In the driest situations, Agrostis capillaris and Moehringia trinervia occur and even some forest dwarf shrubs but at low frequency and cover.  In the northernmost Bothnian Bay, on slightly more calcareous substrate, Geranium sylvaticum, Oxalis acetosella, Filipendula ulmaria, Geum rivale and Anthriscus sylvestris are distinctive.

Indicators of quality:

  • Undisturbed natural hydrology
  • Dominance of mature trees with shrubs forming a subordinate layer
  • Few if any signs of exploitation for timber, fallen trees remaining in situ with ample deposition of natural organic debris from flooding in riparian sites.
  • No signs of eutrophication or pollution by anthropogenically enriched flood or ground waters, for example excessive spread of nutrient-demanding weeds
  • Absence of non-native tree species and absence of invasive aliens such as Reynoutria japonica or Impatiens glandulifera

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

Threat status

Synthesis of Red List assessment

The past present decline in quantity of around 14% is not strong enough to qualify a Near Threatened category and the reported decline in quality has only been slight (36%) on less than half of the area. Neither trend in quality nor in quantity could qualify the Near Threatened category. The situation certainly benefits from nature conservation programms such as Natura 2000, but the pressure remains strong on this habitat that can be easily degradated by river regulation or destruction of trees along agricultural lands (just like other hedgerows), or forest plantations.
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

  • Sylviculture, forestry
    • Forest and Plantation management & use
    • Forest replanting (non native trees)
    • Forestry clearance
    • Removal of dead and dying trees
    • Forest exploitation without replanting or natural regrowth
  • Pollution
    • Pollution to surface waters (limnic, terrestrial, marine & brackish)
  • Invasive, other problematic species and genes
    • Invasive non-native species
  • Natural System modifications
    • Human induced changes in hydraulic conditions
    • Canalisation & water deviation
    • Lack of flooding

Habitat restoration potential

The best thing to restore riparian hardwoods for example from old poplar plantations and fight alien species is to avoid any further strong intervention in the vegetation, because soil perturbation and light on the ground would favour alien species whereas shade will control them.

Trends in extent

Average current trend in quantity

Decreasing Decreasing
EU28 EU28+

Trends in quality

Average current trend in quality

Decreasing Decreasing
EU28 EU28+

Conservation and management needs

Conservation measures include the conservation or restoration of a good functioning of the river with floodings and natural banks, and a protection against clearing and planting of alien species. Clearings and cuttings have not only been done for logging or in favor of other land-use, but also to avoid large woody debris to cause log-jam on the river. Such woody debris are vital for the whole river ecosystem and provide habitat for a lot of species, from the river banks (beaver, birds) and bed (fish nursery, insects, molluscs). Dead or dying trees should be kept unless a log-jam threatens infrastructures just downstream in urbanized areas. Many riparian alnus woodlands along small rivers form only ribbons along agricultural lands, and their conservation must involve farmers, as with the conservation of hedges. It is also important to keep cattle from grazing the banks and going down in the river, as they damage the soil and vegetation. When riparian woods are located along rivers flowing in a forest, their conservation implies forestry steawardship (no logging on the river banks, no crossing by machines).

List of conservation and management needs

  • Measures related to agriculture and open habitats
    • Other agriculture-related measures
  • Measures related to forests and wooded habitats
    • Restoring/Improving forest habitats
    • Adapt forest management
  • Measures related to wetland, freshwater and coastal habitats
    • Restoring/Improving the hydrological regime
  • Measures related to spatial planning
    • Legal protection of habitats and species
    • Manage landscape features

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)
Austria Present 375 Stable Stable
Belgium Present 109 Stable Stable
Bulgaria Present 80 Decreasing Decreasing
Croatia Present 98 Decreasing Decreasing
Czech Republic Present 790 Decreasing Stable
Denmark Present 59 Stable Unknown
Finland mainland Present 20 Stable Stable
France mainland Present 2460 Decreasing Stable
Germany Present 700 Stable Increasing
Greece (mainland and other islands) Present 85 Decreasing Stable
Crete Uncertain 85 Decreasing Stable
East Aegean Uncertain 85 Decreasing Stable
Hungary Present 60 Decreasing Decreasing
Ireland Present 1.3 Stable Stable
Italy mainland Present Decreasing Decreasing
Sardinia Present Decreasing Decreasing
Sicily Present Decreasing Decreasing
Latvia Present 55 Decreasing Unknown
Lithuania Present 441 Decreasing Stable
Netherlands Present 18 Unknown Stable
Portugal mainland Present 176 Decreasing Decreasing
Romania Present 125 Unknown Decreasing
Slovakia Present 50 Decreasing Decreasing
Slovenia Present 37 Decreasing Decreasing
Spain mainland Present 398 Decreasing Decreasing
Sweden Present unknown - Unknown
United Kingdom Present 80 Decreasing Stable
Northern Island Present 80 Decreasing Stable
Gibraltar Uncertain 80 Decreasing Stable
Luxembourg Present unknown - Unknown
Poland Present 2 Decreasing Decreasing
Estonia Present 35 Increasing Stable
EU28 + Present or presence uncertain Current area of habitat (Km2) Recent trend in quantity (last 50 years) Recent trend in quality (last 50 years)
Bosnia and Herzegovina Present 20 Decreasing Decreasing
Switzerland Present 60 Decreasing Stable
Norway Mainland Present unknown Decreasing Unknown
Albania Uncertain - -
Kosovo Uncertain - -
Liechtestein Uncertain unknown Unknown Unknown
Former Yugoslavian Republic of Macedonia (FYROM) Present unknown Unknown Unknown
Montenegro Present unknown Unknown Unknown
Serbia Present unknown Unknown Unknown

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 7882900 16830 6500 6076 is reported but data is missing for several countries. 6500 seems to be a good estimate of the total area for EU 28 according to art 17 and estimates
EU28+ 16896 7000 6155 is reported but data is missing for several countries. 7000 seems to be a good estimate of the total area of EU 28+ according to art 17 and estimates
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

The full list of characteristic species and genus are available above from the Summary. The species available in the EUNIS database are shown here.
Conifers Juniperus communis
Ferns Athyrium filix-femina
Flowering Plants Aegopodium podagraria
Flowering Plants Agrostis capillaris
Flowering Plants Alnus glutinosa
Flowering Plants Angelica sylvestris
Flowering Plants Anthriscus sylvestris
Flowering Plants Betula pubescens
Flowering Plants Calamagrostis canescens
Flowering Plants Crataegus monogyna
Flowering Plants Deschampsia cespitosa
Flowering Plants Filipendula ulmaria
Flowering Plants Fraxinus excelsior
Flowering Plants Galium aparine
Flowering Plants Geranium sylvaticum
Flowering Plants Geum rivale
Flowering Plants Geum urbanum
Flowering Plants Impatiens glandulifera
Flowering Plants Milium effusum
Flowering Plants Moehringia trinervia
Flowering Plants Oxalis acetosella
Flowering Plants Petasites hybridus
Flowering Plants Poa nemoralis
Flowering Plants Prunus padus
Flowering Plants Reynoutria japonica
Flowering Plants Ribes alpinum
Flowering Plants Rubus caesius
Flowering Plants Rubus saxatilis
Flowering Plants Salix fragilis
Flowering Plants Salix phylicifolia
Flowering Plants Sambucus nigra
Flowering Plants Silene dioica
Flowering Plants Solanum dulcamara
Flowering Plants Sorbus aucuparia
Flowering Plants Urtica dioica
Flowering Plants Valeriana sambucifolia
Mosses & Liverworts Brachythecium rutabulum
Mosses & Liverworts Eurhynchium praelongum
Mosses & Liverworts Plagiomnium undulatum
Species scientific name English common name Species group
Juniperus communis Conifers
Athyrium filix-femina Ferns
Aegopodium podagraria Flowering Plants
Agrostis capillaris Flowering Plants
Alnus glutinosa Flowering Plants
Angelica sylvestris Flowering Plants
Anthriscus sylvestris Flowering Plants
Betula pubescens Flowering Plants
Calamagrostis canescens Flowering Plants
Crataegus monogyna Flowering Plants
Deschampsia cespitosa Flowering Plants
Filipendula ulmaria Flowering Plants
Fraxinus excelsior Flowering Plants
Galium aparine Flowering Plants
Geranium sylvaticum Flowering Plants
Geum rivale Flowering Plants
Geum urbanum Flowering Plants
Impatiens glandulifera Flowering Plants
Milium effusum Flowering Plants
Moehringia trinervia Flowering Plants
Oxalis acetosella Flowering Plants
Petasites hybridus Flowering Plants
Poa nemoralis Flowering Plants
Prunus padus Flowering Plants
Reynoutria japonica Flowering Plants
Ribes alpinum Flowering Plants
Rubus caesius Flowering Plants
Rubus saxatilis Flowering Plants
Salix fragilis Flowering Plants
Salix phylicifolia Flowering Plants
Sambucus nigra Flowering Plants
Silene dioica Flowering Plants
Solanum dulcamara Flowering Plants
Sorbus aucuparia Flowering Plants
Urtica dioica Flowering Plants
Valeriana sambucifolia Flowering Plants
Brachythecium rutabulum Mosses & Liverworts
Eurhynchium praelongum Mosses & Liverworts
Plagiomnium undulatum Mosses & Liverworts

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

This habitat may be equivalent to, or broather than, or narrower than the habitats or ecosystems in the following typologies.
Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 200711 G1.2 Mixed riparian floodplain and gallery woodland narrower
European Environment Agency (EEA)
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