Cities in highly industrialised countries have grown over time, yet the phenomenon of shrinking cities occurs in many regions. Urban shrinkage has various impacts on urban ecology, which can be observed on urban brownfield sites in particular. The integration of brownfield sites with sustainable urban development must be managed, and this presents new challenges for urban planners. The introductory chapters of this publication give an overview of urban ecology concepts and how research in this field is affected by urban shrinkage. The following sections are concerned with botanical aspects of shrinking cities, perception of nature in the context of shrinkage and discussion of aspects of urban planning with reference to several regional examples. The book concludes with an examination of urban shrinkage during the life cycles of city archetypes.