This volume presents a unique set of time series data concerning the environmental and biological dynamics of a pristine alpine-boreal river system in Norway. A simultaneous collection of data on climate, hydrology, erosion, water chemistry, primary production, invertebrates and fish provides an unusual insight into the ecology of a watercourse characteristic of this region of north-western Europe. Individual papers present data collected over 14 years, which provides an opportunity to understand the natural dynamics in a system with very little direct influence from human activities. The results indicate a level of variation that should be expected in natural systems, and provides a solid basis for a discussion of the best approach to the monitoring of biological diversity and environmental factors in rivers and lakes. The volume is aimed at researchers working with watershed management and aquatic sciences. It provides useful information and experiences of particular relevance to the implementation of the EU Frame Directive for Water.