Der niederlandische Arzt und Botaniker Steven Jan van Geuns (1767 1795), Studienfreund Alexander von Humboldts in Gottingen, beschreibt in seinem Tagebuch die gemeinsame Reise von 1789. Es ist nach bisherigen Erkenntnissen das einzige ausfuhrliche Dokument uber diese Reise, da das Tagebuch Humboldts offensichtlich schon zu seinen Lebzeiten verloren gegangen ist. Behandelt werden wissenschaftliche Fragen und Probleme unterschiedlicher Gebiete, insbesondere der Medizin, Geologie und Mineralogie, Salinenkunde, Botanik, Landeskunde, wie auch philosophische, geschichtliche und kulturelle Fragen. Der Besuch wissenschaftlicher Sammlungen und zahlreiche Kontakte zu Wissenschaftlern waren Schwerpunkte der Unternehmung. Die daraus entstandenen fruhen wissenschaftlichen Netzwerke wurden von beiden spater ausgebaut. Noch in Humboldts "Kosmos" wird auf Personen aus dieser Zeit Bezug genommen. Van Geuns stellte vor allem Beziehungen zu Medizinern, Chemikern und Botanikern an den besuchten Universitaten her, auch diese Kontakte nach Deutschland haben fortbestanden. Dem Tagebuch sind u. a. bereits wissenschaftliche Ansatze zu entnehmen, die von Humboldt und van Geuns spater in Publikationen weitergefuhrt wurden zum Beispiel in Humboldts 1790 erschienenem Buch uber die Basalte am Rhein oder in den spateren pflanzengeographischen Arbeiten. Das Tagebuch ist ein kulturhistorischer Fuhrer, gewissermassen ein fruher Baedeker, fur Hessen, die Pfalz, das Rheingebiet und Westfalen."

This textbook on urban ecosystems answers important questions about the ecological structure, functions and socio-ecological development of cities worldwide. Based on how cities are developing today in an increasingly urbanized world, it explains ecological challenges for cities of the 21st century such as resource efficiency, climate change, moderation of quality of life and resilience. The book combines theories of urban development and ecology with practical applications and case studies, thus identifying potential for improvement and examples of good ecological urban development worldwide. It shows that cities are by far not only problem areas but also offer great potential for a good life and that the various urban ecosystems can make a considerable contribution to this. The "eco-city" is thus not a utopia,but a real goal that can be pursued step by step in a targeted manner, taking into account the local and regional context. Four renowned urban ecologists have contributed their specific experience in sub-areas without losing sight of the big picture. Jurgen Breuste is an urban ecologist and works at the Paris Lodron University in Salzburg, Austria, on the topics of sustainable urban development, urban biodiversity, ecosystem services and eco-cities. Dagmar Haase is Landschaftsoekologin and works at the Humboldt University of Berlin on urban ecosystem services and land use modeling. Stephan Pauleit is a landscape planner and works at the Technical University of Munich on strategies for the sustainable development of urban landscapes. Martin Sauerwein is a geographer and works at the University of Hildesheim on geo-ecology in cultural landscapes, geoarchaeology and soil protection. The textbook addresses a broad audience of students, teachersand also to practitioners in the fields of ecology, urban ecology, urban development, sustainability, urban geography, nature and landscape conservation, spatial planning, landscape ecology, social sciences and urban studies. The numerous photos and graphics, many of them in four colors, as well as clear tables illustrate the facts. Case studies, examples and explanations allow a deeper insight. Questions at the end of each chapter allow the progress of knowledge to be checked, and a comprehensive bibliography for each chapter provides further studies.This book is a translation of the original German 1st edition Stadtoekosysteme by Jurgen Breuste published by Springer Fachmedien Wiesbaden GmbH, part of Springer Nature in 2016. The translation was done with the help of artificial intelligence (machine translation by the service DeepL.com). A subsequent human revision was done primarily in terms of content, so that the book will read stylistically differently from a conventional translation. Springer Nature works continuously to further the development of tools for the production of books and on the related technologies to support the authors. This springer essential is a translation of the original German 1st edition essentials,Stadtoekosysteme by Jurgen Breuste published by Springer Fachmedien Wiesbaden GmbH, part of Springer Nature in 2016. The translation was done with the help of artificial intelligence (machine translation by the service DeepL.com). A subsequent human revision was done primarily in terms of content, so that the book will read stylistically differently from a conventional translation. Springer Nature works continuously to further the development of tools for the production of books and on the related technologies to support the authors.