Ecosystem fragility to alien and invasive species

Alien species, particularly when invasive, are likely to represent a major issue when dealing with biodiversity even though their impact at the ecosystem level needs to be better understood and quantified. Anyway, their spread affects almost all the ecosystems, and the trend of this phenomenon seems to increase at global scale. Here, we present a first attempt to a quantitative description of the invasiveness of habitat and ecosystem types in Italy through the facilities of the European Research Infrastructure on Biodiversity and Ecosystem Research LifeWatch. The study is adopting an ecosystem level approach in order to assess the fragility of key EUNIS ecosystem/habitat types to alien species. Ecological modeling and geospatial statistics are used to evaluate abiotic conditional factors of the fragility of the most widespread EUNIS ecosystem types along latitudinal and longitudinal gradients in Europe and to map ecosystems fragility at the national and European scale. Ninety-six sites from Italy have been processed and encompassed in 41 habitats (level 2, EUNIS code). Available taxonomical data are referred to about 19,650 records; 10,600 taxa; 10,050 species. The trait "alien species" is going to be harmonized among different taxonomic groups at both geographical and temporal scale. At present, however, the alien trait has been attributed to about 4% of the species data sets, whereas the mean value for Italy is around 3%. The incidence of alien species greatly varies in different environments/habitats, with highest values in terrestrial and freshwater habitats and lowest in marine habitats. Marked differences also occur among different taxonomical groups, with highest incidence of alien species among terrestrial vegetables and vertebrates, lowest for less known groups such as invertebrates.