Abstract

Neobiota as non-native species are commonly considered as alien species. The Convention on Biological Diversity (CBD) intends to “prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats or species”. The European Union has financed the DAISIE research project for the first pan-European inventory of Invasive Alien Species (IAS), which is supposed to serve as a basis for prevention and control of biological invasions. This paper discusses the evaluation approach for classifying “100 of the Worst” IAS in Europe by the EU DAISIE research project. The main impact categories used by DAISIE for assorting “100 of the Worst” IAS are investigated and the texts of the “Wanted” species factsheets are examined. Two examples from the DAISIE factsheets of the “100 of the Worst” IAS [Tree of Heaven ( Ailanthus altissima ) and the Raccoon ( Procyon lotor )] are discussed to illustrate DAISIE’s biodiversity evaluation approach in more detail. However, the classification criteria used by DAISIE do not allow for sufficiently differentiating these neobiota from an ecological behavior of native species with a similar ecological niche. In conclusion, neobiota evaluations are not comprehensive when they refer mainly to the successful expansion and competition with native species into available ecological niches. A comprehensive assessment of the impacts of neobiota on biodiversity and humans needs to take into account the different values of biodiversity as mentioned in the preamble of the CBD