In this edition of the Long Term Ecological Research Network series, editors John Hobbie and George Kling and 58 co-authors synthesize the findings from the NSF-funded Arctic LTER project based at Toolik Lake, Alaska, a site that has been active since the mid-1970s. The book presents research on the core issues of climate-change science in the treeless arctic region of Alaska. As a whole, it examines both terrestrial and freshwater-aquatic ecosystems, and their three typical habitats: tundra, streams, and lakes. The book provides a history of the Toolik Lake LTER site, and discusses its presen