The term Fennoscandia is used to denote Finland and the Scandinavian peninsula, which comprises Norway and Sweden and sometimes also neigh bouring districts of the USSR. The western part of the Scandinavian peninsula is mountainous with peaks mostly within the range 1000-2000 m above sea level. Permafrost is not usually found in the southern districts of these alpine zones, but occurs in the northeastern part of Fennoscandia in mire, even at a low elevation. If tundra is defined as areas of permafrost, only very limited regions of Fennoscandia could be included. However, in the present volumes, we have used the word tundra in a broader sense as approximating areas with mean annual air 0 temperature below 0 C at meteorological standard height (1.5-2 m); it is often used in this sense in North America. This usage allows all alpine zones to be included, along with the subalpine birch zone and certain open subarctic woodland ("forest tundra" in Russian usage)."

The large and rapidly expanding body ofliterature related to nitrogen cycling in both managed and native terrestrial ecosystems reflects the importance accorded to the behaviour of this vital and often limiting nutrient. Research at the organism, ecosystem and landscape levels commonly addresses questions concerning nitrogen acquisition, internal cycling and retention. Goals for this research include increased agricultural productivity and a better understanding of human impact on local, regional and global nitrogen cycles. Nitrogen cycle research in tropical regions has a long and distinguished history. Research on different aspects of nitrogen cycling in ecosystems of the tropics has been carried out in many regions. In relatively few instances has there, however, been a focus on the biogeochemical cycles at the ecosystem level. The meeting resulting in this volume was an attempt to bring together existing information on nitrogen cycling in ecosystems of Latin America and the Caribbean and discuss this in an ecosystem context.

Animals are important components of any ecosystem and it is impossible to describe structure and funCtioning of the Fennoscandian tundra ecosystems without including this part of the system. However, the strong diversity between functionally highly different fauna groups makes it impossible to study all groups in great detail with the funds and expertise available in Fennoscandia. Relatively few productivity studies were carried out on animals in Fenno scandian tundra regions before the IBP projects started in 1969-1970. Within IBP, more fauna groups have been investigated in the Norwegian tundra project than in the other countries, due to better financial support. Even in Norway, however, only a limited number of invertebrate and vertebrate taxons is studied. General lack of information on the same animals in various parts of the Fennoscandian tundra makes it more difficult to present structural and functional comparisons of fauna for the whole region than in plants and microorganisms (see Part 1 of Fennoscandian Tundra Ecosystems). Brief surveys on faunal problems within the area are given in the introduction to the animal section, and general aspects are also discussed in the four first papers of the volume."