ABSTRACT
This chapter gives an exhaustive overview on the main aspects of biological invasions. At first, it determines what invasive alien species are by providing a coherent bio-legal definition. Subsequently, it analyses the phenomenon under the lenses of the DPSIR model, emphasising the expanding role of human agency conceived as a combination of driving forces exerting pressures on nature. A closer look at policy responses to biological invasions emphasises the role of a three-tier approach based on prevention, control and eradication and the need for a multilateral response capable of transcending national borders, in order to achieve a multi-level regulation.
