The Urban Ecosystem -- Humans as a Component of Ecosystems -- Urban Patterns and Ecosystem Function -- Landscape Signatures -- Hydrological Processes -- Biogeochemical Processes -- Atmospheric Processes -- Population and Community Dynamics -- Futures of Urban Ecosystems -- Urban Ecology: A Synthesis. The future of Earth's ecosystems is increasingly influenced by the pace and patterns of urbanization. One of the greatest challenges for natural and social scientists is to understand how urbanizing regions evolve through the complex interactions between humans and ecological processes. Questions and methods of inquiry specific to our traditional disciplinary domains yield partial views that reflect different epistemologies and understandings of the world. In order to achieve the level of synthesis required to see the urban ecosystem as a whole we must change the way we pose questions and search for answers. Cities are the result of human and ecological processes occurring simultaneously in time and in space and the legacy of the simultaneous processes of the past. Urban ecology is the study of the co-evolution of human-ecological systems. Scholars of both urban systems and ecology must challenge the assumptions and world views within their disciplines and work towards a hybrid theory that builds on multiple world views. The synthesis of research findings provided in this book is a first step towards articulating the challenge for scholars of urban ecosystems; it leads the way toward the integration we must achieve if we are to better understand and solve emerging issues in urban ecosystems. Marina Alberti is Associate Professor in the Department of Urban Design and Planning and Director of the Urban Ecology Research Lab (http://www.urbaneco.washington.edu/) at the University of Washington in Seattle, Washington.