In 1985, Abisko Scientific Research Station, situated in the mountains of subarctic Sweden, celebrated the 50th anniversary of its affiliation with the Academy with a symposium entitled Research in Arctic Life and Earth Sciences: Present Knowledge and Future Perspectives. Seven invited papers were presented covering subjects on which research is being done at the station. The abiotic environment of the Arctic, and relateed areas, was described in a series of three papers which discussed mountain climatology, geology and periglacial geomorphology. Four remaining papers considered the biota of the Arctic, from their origins through soil microbiology and plant resource utilisation to population biology. These presented papers are published in this volume together with an additional article discussing Man's direct and indirect influence on the ecosystems of the area, an influence which must, or should be, considered when evaluating environmental data today. This subject is also an important part of the research programme of the station.