Invasive exotic species

The introduction and spread of alien species threatens biodiversity and related ecosystem services. They often also cause impacts on human health and economic activities.

In the Alps, since the postglacial period, the environment has been continuously subject to colonisation by successive waves of plant species, which arrived independently depending on the dispersal capacity of individual species and climatic fluctuations. As anthropogenic impact increased, imported species also became established,
voluntarily or involuntarily, by humans, for example with the advent of agriculture.

These species have adapted to the new environment to the detriment of the species already present: they have developed the ability to establish and maintain viable populations in the wild, which settle so well that they represent a real threat to local biodiversity.

This is a problem that concerns both plant and animal species, and which in Trentino mainly affects low-altitude valley floor environments, particularly along watercourses.

Some environments in Trentino at low altitudes, with little or no endemic components, are sometimes extremely subject to invasion by allochthonous species. These are, in particular, aquatic environments, riparian environments, noble broadleaf woods, chestnut groves, oak and hophornbeam forests. These valuable near-natural environments can be altered or even
destroyed by the invasion of alien woody and herbaceous species. In general, it is the most fertile, moisture-rich, nutrient-rich and not too cold environments that are much preferred by allochthonous species.

As is now well documented, alien species can cause considerable economic damage to productive activities, especially agro-sylvo-pastoral ones. They can also contribute to the spread of diseases and parasites that are harmful to plants and animals, and extremely dangerous for humans as well.

Their possession and trade are strictly regulated by legislation that came into force in all EU countries in 2015, implemented in Italy by DL n. 230 of 15 December 2017. The aim of the legislation is to prevent further introductions of alien species and to mitigate damage due to those alien species already established and widespread on EU territory.

To date, invasive alien species with a significant impact on European ecosystems (so-called Union species) number 144 (including animals and plants), of which 60 are already present in Italy, and are periodically updated.
In Trentino there are at least 18 species:

When prevention and rapid eradication are unsuccessful, containment and control interventions remain. These are costly and often non-resolving interventions, but they are necessary to prevent uncontrolled spread in areas not yet affected.

For more information, please contact:

PAT Sustainable Development and Protected Areas Service: tel. 0461 496109 - 0461 496190

Ministry of the Environment: esoticheinvasive@minambiente.it

Ispra: specieinvasive@isprambiente.it - tel. 06 50072650

Article from l'Adige of 26 August 2019