Red List habitat classification > RLG - Forests > RLG1.Ba Alnus cordata woodland

Alnus cordata woodland

Quick facts

Red List habitat type code RLG1.Ba
Threat status
Europe Data Deficient
EU Data Deficient
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)

Summary

Broadleaved deciduous, non-riparian forests dominated by Alnus cordata, subendemic to Corsica (North-Eastern sectors of the island) and S-Italy (Campania, Basilicata and Calabria Regions). The dominant species is a relict from the Tertiary period and is also present in other areas, where it is considered not native. Biogeographically distributed on the Central-Mediterranean mountains, from the climatic point of view these forests develop preferentially between the hilly and the montane belts, occupying a transitional area between the deciduous oaks and the beech forests. From a geo-pedological point of view, they show a preference for siliceous substrata but can also be found on limestone. Alnus cordata tends to form forests, either pure or mixed with other deciduous species, such as Quercus cerris, Castanea sativa or, at higher altitudes, Fagus sylvatica. They tend to colonize steep slopes and sides of deep valleys. The Italian alder is a strong pioneer species with great affinity for mineral soils, and could largely expand after the drastic economic changes following the Second World War, when large agricultural areas were abandoned and left to natural evolution, especially at higher altitudes. These formations are characterized by very strong pace of growth in the juvenile stage, and quickly reach maturity (Bezzi et al. 1991). Unlike the other species of the genus Alnus, the Italian alder shuns soils where water stagnates for a long time, although it still shows a certain hygrophilous ecology. Regeneration occurs quickly and seedlings can grow fast after cutting or in clearings. Furthermore, Alnus cordata can play a prominent role in improving the soil, due to the presence of radical tubercles hosting microorganisms (Frankia alni) fixing the atmospheric nitrogen (Pirazzi 1984; Ducci & Tani, 2009).

These forest types often show a high environmental quality and host rare or endangered species.

Indicators of good quality:

● Dominance of Alnus cordata

● Presence of the distinctive woody associates and field layer

● Presence of the field layer flora typical of the region

● Uneven-aged canopy with signs of regeneration of woody dominants

● Presence of a well-developed structure of the tree layer

● Woodland permanent, not a successional stage; blocked dynamism due e.g. to the steep slope, where this forests represent the potential natural vegetation

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

Threat status

Synthesis of Red List assessment

The habitat is characterized by a small number of locations (AOO=67), but there is no indication of negative trends or threats. Alnus cordata is a pioneer and fast growing species which can recover after cutting. For southern Italy, without quantitative data, the habitat is considered to be stable, but no information is available for Corsica. Due to limited information, the habitat has been classified as Data Deficient.
EU
Red List Category Red List Criteria
Data Deficient -
Europe
Red List Category Red List Criteria
Data Deficient -

Confidence in the assessment

low
Red List of habitat categories and criteria descriptions

Pressures and threats

  • Sylviculture, forestry
    • Forest and Plantation management & use
    • Grazing in forests/ woodland
  • Climate change
    • Changes in abiotic conditions
    • Changes in biotic conditions

Habitat restoration potential

The dominant species (Alnus cordata) is a strong pioneer species and could largely expand after land abandonment if left to natural dynamic, especially at higher altitudes. These formations are characterized by very strong rate of growth especially in the juvenile stage, and quickly reach maturity. Regeneration occurs quickly and seedlings can grow fast after cutting or in clearings.

Trends in extent

Average current trend in quantity

Unknown Unknown
EU28 EU28+

Trends in quality

Average current trend in quality

Unknown Unknown
EU28 EU28+

Conservation and management needs

Currently no conservation and management approaches are reported. Grazing control is considered important in order to avoid a reduction of the regeneration of the characteristic species.

List of conservation and management needs

  • Measures related to forests and wooded habitats
    • Restoring/Improving forest habitats
    • Adapt forest management

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)
Corsica Present Unknown Unknown Unknown
Italy mainland Present 80 Unknown 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)

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 109000 67 >80 no data available for Corse (FR)
EU28+ 67 >80 no occurrences outside EU28
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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