Research on biological invasions is located at the intersection between natural sciences (biological and physical context) and the social sciences and humanities (social, political and economic context). The concept of ‘social-ecological systems’ (outer light blue box) emphasises that both realms are closely connected, with human activities affecting organisms, communities, ecosystems and landscapes and vice versa. Invasion biology addresses biological questions about patterns and mechanisms of invasions and, thus, has a focal interest in the biological and physical context. The broader field of invasion science contains research analysing patterns and mechanisms of invasions from a social-economic point of view, effects of invaders on people’s values and perspectives and many other, non-biological aspects of species invasions.