European network of IAS costs. This bipartite network is composed of both species and country nodes. Links indicate the cumulative costs of species in European countries over 1960–2020. The larger the link, the higher the cost. Likewise, node size is proportional to the total cumulative cost. For species nodes, node size represents the total cost they had over all countries. For country nodes, the node size represents the total cost of all species in that country. Note that studies reporting costs on ‘diverse’ groups of organisms rather than specific species were excluded from this network.