LIFE 10 NAT/ES/000582
Lucha contra las especies invasoras en las cuencas hidrográficas de los ríos Tajo y Guadiana en la Península Ibérica
Volver a la página de inicio del LIFE+ INVASEP
© Créditos
fotográficos

Beneficiario Coordinador
Cofinanciador
Beneficiario Asociados
Colaboradores
invasep@juntaex.es
© 2017 Consejería de Medio Ambiente y Rural, Políticas
Agrarias y Territorio - DG Medio Ambiente - GPEX
Con la contribución del instrumento financiero LIFE de la Unión Europea
Other languages
Portal INVASEP en castellano
Portal INVASEP en portugués

AAutoecology

Main habitat: it grows in well-drained and degraded soil, by the road, in dumps, riparian habitats, or peri-urban areas.

Features of native and invaded ecosystems: it mainly invades urban and peri-urban areas, but also forest and riverside environments.

Breeding season: it flourishes from May to July, reproducing by seed (up to 35,000 seeds/year). Its fruits mature in Autumn. It regenerates in a vegetative way from stump or root shoots that might be far away from its parent plant.
Ailanthus (Ailanthus altissima))

Species description

Deciduous tree, originally from China, where is also grown to feed silkworms.

Its trunk has a grey bark, which is smooth in young specimens, and cracked in old ones; and it can grow up to 25 m high. It has got compound imparipinnate leaves, with 7-9 pairs of oval to lanceolate leaflets. Leaves are gathered in bouquets at the end of the stem and, in its base, there are lobes with a gland that gives off an unpleasant smell when touched.

Flowers are small, actinomorphic, hermaphroditic, and they are white-yellowish in colour. They are distributed in tessels up to 30 cm long. Male flowers give off an unpleasant smell, so only female specimens are commonly grow. Its type of pollination is wind pollination.
Tolerance to environmental stress factors: it may adapt to a wide range of soils with good drainage.
Pathways of Introduction and Expansion

Ailanthus was introduced in Europe in 1751 for ornamental purposes, and it was considered to be naturalized in Spain in the 19th century. Nowadays, its demographic trend is expansive.

Current use in Spain: It is used in gardening as an alignment tree in streets and roads; and also to stabilize unsteady soils, or as a windbreak.


Main dispersal vectors: it quickly spreads through the wind. Freshwater might be  another dispersal vector for this species.
Impact

Ecological:
this species grows fast, producing between 325,000 and 350,000 seeds per year, and generating vegetative new shoots. It expands fast, creating very dense populations, this way displacing native species. The allelopatic compounds on its leaves make it difficult for nearby native species to germinate, this way contributing to their displacement. These compounds also affect soil micro life in a negative way.

Socio-economical: its root system might be harmful in urban areas, damaging building foundations, sewage systems, and pavements. It might also cause economic losses for beekeepers because bees, after 'visiting' this tree, give honey an unpleasant flavour, which prevents it from being commercialized.

Affected processes, communities or species: this tree may have a strong impact on the soil micro life, as well as it may cause a decrease in the population of insects due to its toxicity. Regarding native vegetation, any species within the invaded area will suffer the effects of the ailanthus due to its allelopatic compounds.

Geographical distribution in the project area
Ailanthus altissima - © Edurado Gómez
Ailanthus altissima - © Edurado Gómez
Ailanthus altissima - © Marcos González
Ailanthus altissima - © Marcos González
Resistance to Pollution: Very High.
Resistance to High Temperatures: High.
Resistance to Salinity: Medium-High.
Resistance to Frosts: High.
Resistance to Draught: Very High.
Resistance to Insolation: Very High.
Resistance to Floods: Medium.
Resistance to Intense Shading: High.