The subalpine lake ecosystem, Øvre Heimdalsvatn, and its catchment: local and global changes over t

This book summarizes research from the intensive study of a pristine subalpine lake ecosystem and its catchment over the last 50 years. A wide range of topics is presented, including several unique time series focusing on changes in ice cover, water temperature, zooplankton, benthos and fish. Significant changes in the lake fauna after the introduction of European minnow into an ecosystem where brown trout was the sole fish species have been documented. The area received substantial radioactive fallout from the Chernobyl accident in 1986, and two articles address long-term changes in radiocaesium activity concentrations in allochthonous plant material and in fish. Other topics include palaeoecology, mercury in fish and remote sensing of catchment snows. Such long-term research is crucial in a rapidly changing environment due to the impacts of climate change, long-range pollutants and alien species. This provides a solid basis for future monitoring and management of freshwater ecosystems. The book will not only be of interest to freshwater ecologists working in the field, but also for managers responsible for the protection and monitoring of natural areas. It illustrates the changes now taking place in pristine ecosystems as a result of human activities and will serve as a supplementary text for courses in environmental management.