subregion from 1970 to 2017. The case studies illustrate a variety of impacts of invasive alien species on both nature and good 
quality of life in different geographic regions, taxonomic groups and realms, but are not meant to be representative. The bottom row 
shows the taxonomic distribution (i.e., plants, invertebrates, vertebrates and microbes, including fungi) of the percentage of invasive 
alien species documented as causing local extinctions of native species (left); the estimated global annual average economic cost of 
biological invasions in billions of United States dollars (centre); and the percentage of the number of documented positive and negative 
impacts of invasive alien species on the constituents of good quality of life (i.e., freedom of choice, health, material and immaterial 
assets, safety, social and cultural relationships) (right). a: {4.3.1, Table 4.3}; b: {4.4.1, Box 4.13}; c: {4.5.1, Table 4.20}. The scientific 
names of the example species are Carcinus maenas (European shore crab); Batrachochytrium dendrobatidis (chytrid fungus); Carijoa 
riisei (branched pipe coral); Wasmannia auropunctata (little fire ant); Lates niloticus (Nile perch); Cenchrus ciliaris (buffel grass); Boiga 
irregularis (brown tree snake); and Reynoutria japonica (Japanese knotweed).
SUMMARY FOR POLICYMAKERS
19SUMMARY FOR POLICYMAKERS
BACKGROUND
A5 