Provides a synthesis of the patterns, causes and consequences of biodiversity in cold-dominated ecosystems. The first chapters document patterns and causes of genetic and species diversity of plants and animals, emphasising the interaction between historical and contemporary factors in governing biodiversity. Subsequent chapters address how biotic diversity has changed in the past, how it is currently changing, and how it is likely to respond to future changes in climate and land use. The third section treats both the conceptual basis and the evidence that biodiversity influences the functioning of arctic and alpine ecosystems. Finally, the implications of terrestrial patterns of biodiversity for landscape patterns and patterns of biodiversity in aquatic ecosystems are covered.