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> Invasive plants in Israel > Ailanthus altissima Swingle

Ailanthus altissima (Mill.) Swingle
Life form: Deciduous tree
En: Tree-of-heaven, Chinese sumac, Fr: Ailante glanduleux, Faux-vernis du Japon
Provenance: Southeast China, Taiwan

Distribution in Israel
The tree-of-heaven is a widespread alien species in the Mediterranean region of Israel which occurs generally in low densities and mainly along roadsides. Exceptions are in the Judean mountains region, west to Jerusalem, and in the eastern Galilee, where it forms large populations in protected sites and in open areas.
The nature reserve of 'Nahal Halilim', west of Jerusalem, is probably one of the protected sites which is most infested with the tree-of-heaven. In this reserve Ailanthus altissima forms tall and dense thickets where a single native plant species cannot be found.

Proliferation status
Ailanthus altissima in Israel is considered an invasive species, according to terminology suggested by Richardson et al. (2000).

Ailanthus altissima in Israel
The tree-of-heaven was introduced in Israel presumably during the 1920s during the British mandate period. The tree was intensively used in urban gardening during the 1970s in the capital city, as it grows extremely rapidly. It was decided to stop planting Ailanthus altissima in the late 1980s because it had started to proliferate within the urban area causing damage to sidewalks, streets, and other built-up structures.
The cities where Ailanthus altissima has been planted today constitute the major proliferation source toward surrounding open and protected areas. Unlike some other invasive alien plants the tree-of-heaven does not occur only on road sides, but can develop and form large populations also in undisturbed sites such as nature reserves.
The tree-of-heaven poses a serious threat to natural areas in Israel, particularly in the Judean Hills region. Yet, it is still possible to stop its proliferation provided immediate measures are undertaken: (1) Eradication of the planted tree individuals in urban areas, (2) control of the trees that have developed in protected areas, (3) follow-up. A lack of control program will inevitably result in a large scale proliferation comparable to that of Acacia saligna.

Physical control is effective only when roots can be removed. The plant resprouts vigorously and therefore felling the trees is not effective and may even be counter-productive. Chemical treatments have proved relatively effective: Glyphosate can be spayed directly on foliage or injected into the trunk; picloram can be used for treating cut stumps.
A research study currently in progress near Jerusalem has shown that the injection of undiluted glyphosate with the drill-fill method has led to a cessation of photosynthetic activity for 78% of the trees treated, while 100% of the targeted individuals did not produce seeds. Yet, follow-up and monitoring are necessary in order to assess for the effectiveness of the treatment through time.

Knapp L.B. & Canham C.D. (2000) Invasion of an old-growth forest in New-York by Ailanthus altissima; sapling growth and recruitment in canopy gaps. Journal of the Torrey Botanical Society 127:307-315.

Lawrence J.G., Colwell A. & Sexton O.J. (1991) The ecological impact of a allelopathy in Ailanthus altissima (Simaroubaceae). American Journal of Botany 78(7):948-958.

Pannill P. (1995) Tree-of-Heaven Control. Maryland Department of Natural Resources Forest Service Stewardship Bulletin. 8 pp.

Last Modified: Friday, 20 January 2006

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