The book is based on data collected during the past 10 years by Zackenberg Ecological Research Operations (ZERO) at Zackenberg Research Station in northeast Greenland. This volume covers the function of Arctic ecosystems based on the most comprehensive long-term data set in the world from a well-defined Arctic ecosystem. Editors offer a comprehensive and authoritative analysis of how climate variability is influencing an Arctic ecosystem and how the Arctic ecosystems have inherent feedback mechanisms interacting with climate variability or change.