After 23 formative and producive years as Director of the Abisko Scientific Research Station, Mats Sonesson will retire from his duties. To honour Mats, to celebrate his career, and to thank him for all that he has done to enhance our research, we have asked those scientists who have worked at Abisko within the subject areas closest to Mats' interests, to contribute to this Festschrift which overviews the ecology and environment of the Tornetrask region. Twenty-three chapters written by 41 scientists from 10 countries have been contributed.

P. S. Karlsson and Terry V. Callaghan are the authors of Ecological Bulletins, Bulletin 45, Plant Ecology in the Sub-Artic Swedish Lapland, published by Wiley.