Managing the Urban Greens : Maintaining ecological functions in human dominated landscapes

Abstract: At the core of this thesis lie two realisations: First, like other ecosystems, those in urban landscapes provide humans with a number of ecosystem services, some recognized while others are not. Second, in cities just as in other intensively used social-ecological systems, management is of central importance. This thesis focuses on how we may manage green areas in cities in an ecologically sustainable way, and enjoy functioning ecosystems close to where most people live. The thesis has four specific objectives: 1) analyse methods for describing the urban landscape, 2) analyze methods for managing urban landscapes rather than single patches of urban green areas, 3) explore the effects of management on diversity patterns and its implications for ecological functions, and 4) investigate the motivations behind the use of different management practices.My results show that changes in urbanization were most distinct at a small scale and that the presence of different bird species depended mostly on access to habitat. They also show that groups of small habitat patches can maintain many of the values of larger patches as long as they are sufficiently close for the organism to move between them, and that matrix heterogeneity must be accounted for. To identify such connected patches and assess their ecological importance I have developed two modelling approaches, one to select suitable model organisms and one to analyse spatial configuration. Further, management is shown to create ecological differences even in areas that are superficially similar, and the roots to these differences are ascribed to the knowledge, institutions and sense of place among different groups of managers. Finally, I try to combine these objectives and sketch out how the organisation of management could be changed to overcome scale mismatches and rigidity. There is potential, both for protection and for management, at all scale levels and this potential should be tapped and nurtured to improve our ability to cope with changes.