Adapted by: P. Schildknecht & C.A. Burga, Geographisches Institut der Universität Zürich, 2008
Cherry Laurel, Tree of Heaven and Black Locust are invasive alien species in Switzerland (Info Flora - List of invasive neophytes in Switzerland, 2014).
Illustrations: Flora der Schweiz und angrenzender Gebiete; Band 2, 1970; Hess, Landolt und Hirzel, Birkhäuser Verlag. Under permission from Springer Nature.
Wood with numerous exotic species with leathery and evergreen leaves (laurophylls).
Photo: Museo cantonale di storia naturale
Neophytes are exotic plants that were introduced by man after 1500 and observed in the wild. The discovery of America marked a considerable increase in trade in species between the world›s regions. Exotic plants introduced before this date are instead defined as archaeophyte and are considered an integral part of the indigenous flora. Most exotic species do not find the ideal conditions to survive in the wild or, if they can reproduce and spread spontaneously, do not cause problems. Some, however, settle and expand significantly, causing obvious damage to biodiversity, human health and the economy: they are therefore referred to as invasive neophytes.
The exotic flora of Monte Caslano includes 45 neophytes, of which 14 are invasive. Some were introduced as part of reforestation carried out at the beginning of the twentieth century; others, such as the cherry laurel, Japanese arrowroot and windmill palm became established by themselves, originating from parks and gardens. Thus, particularly near settlements, new types of woodland are noted, characterised by the presence of numerous exotic species and generally poor in indigenous species, such as woods with evergreen broadleaf species (called laurophylls) and black locust.
To limit the damage caused by invasive neophytes, intervention is carried out where possible.
For example, targeted projects between the Municipality of Caslano and the Department of the Territory of Canton Ticino try to contain the growth of the populations of ailanthus, a species native to East Asia that colonises the southern slope of the mountain. Ailanthus is a very competitive tree and poses a serious threat to biodiversity. The aim of the project is not to eradicate the tree, which is certainly desirable but difficult to achieve due to the harshness of the soil, but to contain its expansion through managed interventions aimed at safeguarding the environment of the mountain, such as its dry meadows.
