This book is the result of a decade or so of work, much of which has been performed in collaboration with colleagues and students. These many collaborations have been instrumental in shaping my views and establishing the results summarized here. Fred Guichard, Bart Haegeman, Florence Hulot, Shawn Leroux, and Elisa Thébault gave useful comments on some of the chapters. Bob Holt and an anonymous reader reviewed the entire book and provided valuable suggestions to improve it. My book also benefited from intense scrutiny and passionate discussions from the students attending my course, Linking Community and Ecosystem Ecology, at McGill University. Brad Cardinale, Evan Economo, Kevin Gross, Helmut Hillebrand, Tony Ives, Tim Keitt, Tommy Lennartsson, Kathleen LoGiudice, Birte Matthiessen, Sam McNaughton, Patrik Nilsson, Rick Ostfeld, Jonathan Shurin, Chris Steiner, Dave Tilman, Juha Tuomi, Jasper van Ruijven, and my various coauthors kindly provided copyright permissions and/or electronic files of some of the figures reprinted or modified in the book. Amy Long’s help in obtaining copyright permissions was particularly appreciated. I thank all of them gratefully. My warmest thanks go to Claire de Mazancourt, who not only read the whole book but also gave constant support in the form of love, understanding, occasional technical help, and scientific contribution to some of the new results presented in chapter 5.