|Tree of Heaven||ISEIA: C1|
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Report the species
→ Report Ailanthus altissima to the National Museum of Natural History.
Ailanthus altissima (Mill.) Swingle is a fast-growing, light-demanding and thermophilic pioneer tree species. It grows best on nutrient-rich soils and is very tolerant to dryness and air pollution. It is mostly found in waste and disturbed areas, but can also invade different kinds of forest ecosystems, riparian areas, rock outcrops and semi-natural grasslands. Winged seeds are easily dispersed by wind and water over distances exceeding several hundreds of metres (Branquart et al. 2017).
Ailanthus altissima successfully displace native vegetation due to its rapid growth and root suckering. It produces allergenic toxins in bark and leaves. As these accumulate in the soil, they inhibit the growth of other plants (allelopathic interactions), favour the formation of monospecific stands and inhibit vegetation succession. Ailanthus also increases soil N content and pH. Ailanthus can reduce soil water availability in case of severe infestation. It may damage roads and other infrastructures due to strong and rapid root development (Branquart et al. 2017).
Status and distribution in Luxembourg
The oldest reference to Ailanthus altissima in Luxembourg is found in the flora of Krombach (1875: 108) who lists it as a cultivated species. To mention an old example, Jean Feltgen (1833-1904) included a specimen from a garden in Diekirch in his herbarium, unfortunately without mentioning a date (Specimen № 15467, MNHNL 2000-). It can still be considered the first record of the species before 1905.
The first documentation of the Tree of Heaven in the wild dates from 1993. It was recorded on 13 July 1993 by Léopold Reichling in the Pfaffenthal district in Luxembourg City (Obs. key: LUXNATFUND431045, MNHNL 2000-). According to Lambinon & Verloove (2012: 463) the species is quite rare in urban areas (AR) and very rare in rural areas in the territory of the flora.
For two decades the species did not appear to have spread to the wild. It is only in recent years that the species was planted in several urban areas and appeared in the wild on sandstone cliffs in Luxembourg City.
Considering the recent expansion of the species in Luxembourg and its probable future increased spread due to climate change, and to avoid major problems urban areas experience with the Tree of Heaven as a weed across Europe, Ailanthus altissima should be listed in the national list of invasive alien species of Luxembourg concern pursuant to Article 12(1) of the EU Regulation 1143/2014 on Invasive Alien Species. Ailanthus should not be planted any more as an ornamental tree and existing populations should be eradicated.
Ailanthus as ornamental tree in urban areas
- On 23rd July 2014 a complete alley of Ailanthus altissima was discovered in the street Porte de France in Belval / Esch-sur-Alzette. It was recently planted in the course of the regeneration of the brownfield site into a large scientific and cultural centre, including the science faculty of the University of Luxembourg (Steil 2014, pers. comm.).
- A group of Ailanthus altissima trees was recently planted behind the Olympic swimming pool in the Kirchberg disctrict of Luxembourg City by the Fonds du Kirchberg. Seedlings have already started to spread on this site (Helminger 2018, pers. comm.).
- A row of 9 Ailanthus altissima was planted before 2008 along a parking area behind the church of Walferdange (Welter et al. 2008: 81; map).
- A single tree is present in the section of the municipal park situated between Avenue de la Porte-Neuve and Avenue Émile-Reuter in Luxembourg City (on the side of the Avenue de la Porte-Neuve in line with two trees of Corylus colurna. Two single trees can be found in the Rue du Rollingergrund, one in front of the house n°294 and another next to the residence on n°306 (Welter et al. 2008: 81).
- A single old tree with several saplings and a single younger grown-up tree were observed on 10th June 2018 in the municipal park of Diekirch situated along the river Sûre.
These are typical examples of a worst case scenario. In a few decades, with climate change helping, Ailanthus might grow in many pavement rinds, flowerbeds and vague grounds all over these sites and possibly into the wild in adjacent areas.
Ailanthus in the wild
In 2018, two populations of Ailanthus altissima were sighted on the edge of the cliff along the railway to Wasserbillig between the Plateau du Rham and the INS and above n°11 Bisserweg (Grund district, Luxembourg City).
ISEIA protocol: C1 (1+1+1+1) (Ries et al. 2013: 18).
- Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum & F. Verloove, 2017. Harmonia database: Ailanthus altissima (Mill.) Swingle. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-23]
- Krombach, J.-H.-G., 1875. Flore du grand-duché de Luxembourg. Plantes phanérogames. 564 p. Luxembourg, Imprimerie Joris.
- Lambinon J. & F. Verloove, 2012. Nouvelle flore de la Belgique, du grand-duché de Luxembourg, du Nord de la France et des régions voisines. Sixième édition. Avec la collaboration de L. Delvosalle, B. Toussaint, D. Geerinck, I. Hoste, F. Van Rossum, B. Cornier, R. Schumacker, A. Vanderpoorten et H. Vannerom. Jardin botanique national de Belgique, Meise. CXXXIX + 1195 pp. ISBN : 9789072619884.
- MNHNL, 2000-. Ailanthus altissima in Recorder-Lux, database on the natural heritage of the Grand Duchy of Luxembourg. Musée national d’histoire naturelle, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2018-01-08]
- Ries, C., Y. Krippel, M. Pfeiffenschneider & S. Schneider, 2013. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of non-native vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 114: 15-21. [PDF 652 KB]
- Welter A., J.Turk & J. Trossen, 2008. Les arbres introduits au Luxembourg. Inventaire des essences arborescentes non indigènes de pleine terre présentes sur le territoire du Grand-Duché de Luxembourg. Ferrantia 53, Musée national d’histoire naturelle, Luxembourg, ISSN 1682-5519, 111 pp.
Alley of Alianthus altissima, Porte de France, Belval, Esch-sur-Alzette. Photos by Yan Steil, 23rd July 2014.
Suggested citation of this webpage
Ries, C. & M. Pfeiffenschneider (Eds.), 2019. Ailanthus altissima (Mill.) Swingle. In: neobiota.lu - Invasive Alien Species in Luxembourg. National Museum of Natural History, Luxembourg. URL: https://neobiota.lu/ailanthus-altissima/ [Accessed 2019-11-17].