Alnus cordata 

Scope: Global & Europe
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Plantae Tracheophyta Magnoliopsida Fagales Betulaceae

Scientific Name: Alnus cordata (Loisel.) Duby
Common Name(s):
English Italian Alder, Alder of Corsica, Hartbladige Els
Spanish Aliso
Alnus cordata fma. parvifolia Callier
Alnus cordifolia Ten
Alnus cordifolia var. rotundifolia Regel
Alnus macrocarpa Req. ex Nyman
Alnus nervosus Dippel
Alnus neapolitana Savi
Alnus obcordata C.A.Mey. ex Steud
Betula cordata Loisel
Taxonomic Source(s): The Plant List. 2017. The Plant List. Version 1.1. Available at:

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2017
Date Assessed: 2017-07-05
Assessor(s): Shaw, K., Wilson, B. & Roy, S.
Reviewer(s): Gargano, D. & Allen, D.J.
Contributor(s): Gargano, D. & Peruzzi, L.

This species has a limited natural range in Corsica and southern Italy, with previous records from Albania considered to be erroneous. However much of the range of this species occurs in protected areas, and it also spreads readily and rapidly, and has become naturalised both elsewhere in Europe and on other continents. It is therefore not considered to be threatened, however some current and potential threats have been identified, including; a reduction in clear cutting practices in protected areas which could have a negative impact on population growth, competition from other species, climate change at lower altitudes, and root rot caused by the pathogen Phytophthora alni. Active conservation management within protected areas and population studies are advised for this species, to ensure it does not become threatened in future. It is assessed as Least Concern globally and for the EU 28 member states.

Previously published Red List assessments:

Geographic Range [top]

Range Description:This European endemic species has a restricted natural range in south-central Corsica and southern peninsular Italy on the western side of the Apennines (Caudullo and Mauri 2016). The species was previously also reported as native to mountains in northwestern Albania, however Barina et al. (2013, 2015) consider this to be based on erroneously identified voucher specimens. The species has become naturalised in Belgium, Spain and the Azores, and has been introduced widely elsewhere, including within Italy (central and northern peninsula and Sardinia), to the UK, and to other continents.
Countries occurrence:
France (Corsica); Italy (Italy (mainland))
Belgium; Netherlands; Portugal (Azores); Spain (Spain (mainland)); United Kingdom
Additional data:
Continuing decline in extent of occurrence (EOO):No
Lower elevation limit (metres):300
Upper elevation limit (metres):1600
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:There is little detailed population information available for this species, but the habitat trend is considered to be stable. In Italy, the species is substantially stable, and in Basilicata and Calabria regions, the species was widely used for forestry purposes in the past, therefore extensive plantations were added to the natural populations (D. Gargano pers. comm. 2017).
Current Population Trend:Stable
Additional data:
Continuing decline of mature individuals:No
Extreme fluctuations:UnknownPopulation severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:This is a deciduous medium-sized tree growing to 17-25 m tall, although up to 28 m in favourable conditions. It is a very rigorous species and can grow over 15 m high in 20 years. It has grey-brown bark with numerous lenticles, the leaves are oval to rounded and serrated, glossy green on the upper side and with a few brown hairs on the underside. New leaves at the beginning of the season are orange-tinged. This species is monoecious, the male flowers are catkin-like and yellow green, the female flowers hang in clusters and are reddish green and very small. The fruit is cone-like, woody and reddish brown in colour, containing numerous small winged seeds. 

This species is the least dependent upon permanent standing water in close proximity to its roots, compared to other Alnus species. Generally a montane and sub-montane species (Caudullo and Mauri 2016), it can be found in dry woodlands and lowland areas although it does prefer damp soils, in poorly drained areas and depressed sites where it can make dense thickets. It grows in semi-shade or no shade. The plant can tolerate maritime exposure, and is also able to colonize marginal or burned areas.
Continuing decline in area, extent and/or quality of habitat:No

Use and Trade [top]

Use and Trade: This species is grown as an ornamental tree and produces valuable wood (Orwa et al. 2013, Caudullo and Mauri 2016). The timber can be used for construction purposes in wet conditions as the wood is virtually resistant to decay under water. It has been used for foundation poles for houses and bridges in Venice. The timber is also used for carving as well as for the production of moulding, furniture, panelling and plywood. It can also be used for firewood. This species has a heavy leaf canopy and when the leaves fall in autumn they help to build up the humus content of the soil. For these reasons it has largely been utilised in central Italy for reforestation of badly drained and wet soils, and for agro-forestry purposes. In recent decades, this species has been widely used in Italy as a shelter species for walnut (Juglans regia), wild cherry (Prunus avium) and other noble hardwoods in intensive forest tree-farming programmes. The pseudo-cones are used as Christmas floral ornaments.

Threats [top]

Major Threat(s): This species has a limited natural range, however it can spread rapidly and natural regeneration occurs readily and rapidly in forest gaps, but the reduction of clear cutting in mixed forests and in protected areas might therefore have a negative impact on population growth of this species. Competition from other species also presents a threat, grazing, and climate change may present a threat to parts of its distribution in lower altitudes, which could result in a loss of genetic diversity (Caudullo and Mauri 2016). Horticultural cultivation could also lead to a reduction in genetic diversity in new plantations if seeds are not selected from a wide number of trees. It has been reported that this species is affected by Phytophthora alni, causing root rot (Webber et al. 2004, Caudullo and Mauri 2016). It is unknown to what extent this disease will affect this species in future, but it currently does not present a major threat to natural sub-populations.

Conservation Actions [top]

Conservation Actions: Much of the natural range of this species occurs in protected areas, however some threats such as climate change, could still adversely affect the species. In situ conservation could be achieved through creating clear felled areas of forest which would allow regeneration. Active management for this species within protected areas and population studies are advised for this species.

Citation: Shaw, K., Wilson, B. & Roy, S. 2017. Alnus cordata. The IUCN Red List of Threatened Species 2017: e.T194657A117268007. . Downloaded on 15 October 2018.
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