Delivering Alien Invasive Species Inventories for Europe: DAISIE as a tool for addressing biological invasions

The 2002 European Strategy on Invasive Alien Species encouraged the development of a pan- European inventory of invasive alien species. In response, the European Commission supported the 3- year DAISIE (Delivering Alien Invasive Species Inventories in Europe) project. The DAISIE internet gateway (www.europe-aliens.org), published in 2008, brings together Europe’s information on alien species and their impacts, and for the first time has developed an overview and assessment of biological invasions in the Pan-European region (Nentwig et al. 2008). The key results from DAISIE are presented. Over 10,600 alien species within Europe have been identified, the majority (60%) of which are vascular plants, followed by terrestrial invertebrates (25%) and aquatic marine species (10%). The arrival rate of new alien species to Europe is increasing for many species groups; at the current rate, one new alien mammal species is introduced to the continent each year for example. Vertebrates tend to be deliberately released, invertebrates generally arrive as contaminants of plant material and most plants escape from gardens. Overall, around one in six European alien species are known to have an ecological or economic impact. The DAISIE inventory, accounts, and distribution maps today provide the first qualified reference system on invasive alien species for the European region. The information presents an outstanding resource to synthesise current knowledge and trends in biological invasions in Europe. DAISIE helps identify the scale and spatial pattern of invasive alien species in Europe, understand the environmental, social, economic and other factors involved in invasions. The potential for DAISIE to form a key component of the emerging European Strategy on Invasive Alien Species is discussed.