The United Nations Conference on the Environment and Development (UNCED), held in Rio de Janeiro in 1992, spawned a multitude of pro grammes aimed at assessing, managing and conserving the earth's biological diversity. One important issue addressed at the conference was the mountain environment. A specific feature of high mountains is the so-called alpine zone, i. e. the treeless regions at the uppermost reaches. Though covering only a very small proportion of the land surface, the alpine zone contains a rela tively large number of plants, animals, fungi and microbes which are specifi cally adapted to cold environments. This zone contributes fundamentally to the planet's biodiversity and provides many resources for mountain dwelling as well as lowland people. However, rapid and largely man-made changes are affecting mountain ecosystems, such as soil erosion, losses of habitat and genetic diversity, and climate change, all of which have to be addressed. As stated in the European Community Biodiversity Strategy, "the global scale of biodiversity reduction or losses and the interdependence of different species and ecosystems across national borders demands concerted international action". Managing biodiversity in a rational and sustainable way needs basic knowledge on its qualitative and quantitative aspects at local, regional and global scales. This is particularly true for mountains, which are distributed throughout the world and are indeed hot spots of biodiversity in absolute terms as well as relative to the surrounding lowlands.

This is the first ever European-wide overview of biodiversity in alpine areas. The volume draws together taxonomic, ecological, historical, functional and climatic studies to develop a holistic understanding of biodiversity at and above the treeline. The main themes are: plant, vegetation and animal diversity, altitude gradients and spatial patterns, long-term changes and the effects of herbivores on diversity. These themes are introduced by a geo-biological scene setting and by a novel characterisation of alpine bio-climate. The comparisons of current and long-term observations and data emphasise the historical tradition of alpine biodiversity research in Europe. Analyses of taxonomic and assembly data at the continent-wide scale provide insight into pattern and its historical and ecological causes.