This volume is based on papers presented at "The Norway/United Nations (UN) Conference on Alien Species" which was hosted by the Norwegian Ministry of the Environment in collaboration with the United Nations Environment Programme (UNEP), the Secretariat of the Convention on Biological Diversity, the United Nations Educational, Scientific and Cultural Organisation (UNESCO), the International Conservation Union (lDCN) and the Scientific Committee on Problems of the Environment (SCOPE) of the International Council of Scientific Unions (ICSU). The organisation and sponsoring of the conference was also a joint venture between the Norwegian Ministry of Environment, the Ministry of Agriculture, the Ministry of Fisheries and the Ministry of Foreign Affairs. The Conference was held at Royal Garden Hotel, Trondheim, Norway, 1-5 July 1996. This was the second Trondheim Conference on Biodiversity, the first being the NorwaylUNEP Expert Conference on Biodiversity, 24-28 May 1993. The conference was organised by the Norwegian Directorate of Nature Management, the Norwegian Institute for Nature Research (NINA) and the Norwegian University for Science and Technology (NTNU) and its Centre for Environment and Development (SMU), all based in Trondheim. These institutions are all active in the fields of management, education and research related to biological diversity. Weare extremely grateful for the support we have received from all these national and international institutions.

Invasive alien species are among today's most daunting environmental threats, costing billions of dollars in economic damages and wreaking havoc on ecosystems around the world. In 1997, a consortium of scientific organizations including SCOPE, IUCN, and CABI developed the Global Invasive Species Programme (GISP) with the explicit objective of providing new tools for understanding and coping with invasive alien species.
Invasive Alien Species is the final report of GISP's first phase of operation, 1997-2000, in which authorities from more than thirty countries worked to examine invasions as a worldwide environmental hazard. The book brings together the world's leading scientists and researchers involved with invasive alien species to offer a comprehensive summary and synthesis of the current state of knowledge on the subject.
Invasive alien species represent a critical threat to natural ecosystems and native biodiversity, as well as to human economic vitality and health. The knowledge gained to date in understanding and combating invasive alien species can form a useful basis on which to build strategies for controlling or minimizing the effects in the future. Invasive Alien Species is an essential reference for the international community of investigators concerned with biological invasions.