It collects the articles of the symposium of the same name that took place lloc in 2009 at the Graduate School of Design of Harvard University, as well as other essays, conferences and lli related to this line of research sponsored by the famous American university. The book, edited by Mohsen Mostafavi and Gareth Doherty, is based on an interdisciplinary approach on brings together the views of architects, urban planners, designers, theorists, economists, engineers, artists and scientists, among other specialists. The result is a wide panorama that contributes to drawing the plural, complex and nuanced image that the urban system acquires quan is studied from an ecological perspective. An important contribution, in short, that gives a charter of nature to a new tica and extended tica of what is urban.