1 Exotic species (alien species, allochthonous species) Any living individual of a species, subspecies or other taxon of plant, animal, fungus, or micro-organism accidentally or willingly transported by humans outside of its past or present native range, including their parts, gametes, eggs, seeds, or propagules, and any hybrids or varieties thereof that may survive and subsequently breed;
2 Established exotic species Any exotic species whose population can be considered established and self-sustaining, meaning that it can survive and breed over much of the range it has recently colonized;
3 Invasive exotic species (invasive alien species) An exotic species whose introduction and establishment, when subjected to a risk assessment, proves to be a threat to local biodiversity and ecosystem services, and could prove harmful to human health and the economy;
4 Invasive alien species of EU concern Invasive alien species whose negative impacts are considered serious enough to warrant a concerted effort at the European Union level in compliance with article 4, paragraph 2 of the EU Regulations;
5 Invasive alien species of national concern Invasive alien species whose negative impacts are considered serious enough to warrant a concerted effort at the national level in compliance with article 10 of the EU Regulations;
6 Biodiversity The diversity of all living organisms, of any origin, including terrestrial, marine, and freshwater ecosystems and the ecological complexes to which they belong; includes diversity within and between species and ecosystems;
7 Introduction The human-induced displacement (voluntary or accidental) of a species outside its current or past range;
8 Intentional introduction The intentional displacement and/or release on the part of humans of a species outside of its natural range, often for the purpose of creating established populations of exotic species;
9 Not intentional introduction (accidental) All other cases of unintentional introduction, for example through the emptying of ballast tanks on ships;
10 Pathways The vectors and mechanisms of biological invasions;
11 Early detection/early warning The detection of an invasive species before it becomes widespread and established;
12 Eradication The complete, permanent elimination – using physical, chemical, or biological means - of a population of an invasive species;
13 Containment Activities aimed at creating barriers that minimize the risk of an invasive species expanding beyond its current range;
14 Population control Physical, chemical, or biological actions carried out against an invasive alien species in order to keep its population as low as possible. In cases where eradication is not possible, population control minimizes the invasive capability of alien species and their negative effects on biodiversity, ecosystem services, human health, and the economy;
15 Risk analysis Assessment of the consequences of the introduction of an exotic species and of the likelihood of its establishment, carried out using scientific information and including the identification of measures that may be adopted to reduce or manage such risks, keeping socio-economic and cultural factors into account;
16 Impact of invasive alien species

Invasive species can seriously harm the development and productivity of certain human activities; indeed, they can reduce agricultural, forest, and fishing harvests. Invasive species can damage infrastructure: animals can dig tunnels, while roots –such as those of the Tree-of-heaven (Ailanthus altissima) – can damage pavement, walls, and archeological sites. Health problems such as allergies and skin rashes can be caused by invasive plants such as Giant Hogweed (Heracleum mantegazzianum) and Common Ragweed (Ambrosia artemisiifolia). The Asian Tiger Mosquito (Aedes albopictus), introduced accidentally to Europe through the transport of used tires, is increasingly widespread and is a vector for over twenty-two arboviruses (including dengue fever, Chikungunya fever, Ross River fever, and the West Nile virus).

17 Plant Health Directive

European Union directive on the protective measures to be taken against the introduction and spread within the European Community of organisms harmful to plant or plant products (2000/29/EC). It is based on guidelines issued by the International Plant Protection Convention overseen by the FAO and within the framework of the World Trade Organization’s Agreement on the Application of Sanitary and Phytosanitary Measures;

18 Habitats Directive (92/43/EEC) European Union directive that establishes a protection framework of species and habitats of Community interest; article 22 (b) establishes that the introduction of non-native species that may prejudice natural habitats must be regulated and, if necessary, prohibited;
19 Best practices Technical norms to be adopted at various planning and land management efforts to reduce the negative impact of invasive alien species and to prevent the risk of new introductions. These are often voluntary norms that call for the involvement of affected stakeholders (farmers, plant nurseries, forestry workers, fishermen, pet dealers, managers of zoos and botanical gardens, etc.) in addition to training and awareness-raising activities;
20 DAISIE (Delivering Alien Invasive Species Inventories for Europe)

the DAISIE project, funded by the sixth framework programme of the European Commission, features an informative website on biological invasions in Europe. The website was created with the support of an international team of leading experts and an extensive network of European collaborators and stakeholders. It provides an inventory of the invasive species that threaten Europe’s terrestrial, freshwater, and marine environments. The website is constantly updated and allows users to search for information on the over 10,000 exotic species currently known to occur in Europe. The web pages on individual species contain information on their biology, ecology, habitat, distribution (including detailed maps), introduction pathway, degree of invasiveness, impact, management, and prevention (http://www.europe-aliens.org/).