Biodiversity and green infrastructure in urban landscapes

Sammanfattning: In this thesis, I evaluate the extent to which biodiversity is affected, and taken into consideration by, urban planning. Based on landscape ecology, I apply an interdisciplinary approach. In addition to natural science, I have included social and political sciences, as methods from these two disciplines were required to study issues dealing with both biodiversity and urban planning.Urbanisation affects biodiversity in several ways. For example, changes in vegetation structures as well as an increased fragmentation of natural habitats will take place. In a fragmented environment an increased nest predation rate occurs. In the smaller spatial scale, predation rate was found to be higher closer to the edge of natural habitat patches than further inside. I also carried out research in order to identify the local and regional effects that cities have on compositional and structural elements of biodiversity. The amount and quality of green space and natural vegetation increased from the centre to the periphery of the city. Avian species richness showed the same trend with the exception of avian generalists, which showed the opposite trend. Certain qualities such as old-growth trees and dead wood, as well as availability of green space, were identified as being important for avian diversity. These findings emphasise the importance of urban green space with natural structures to maintain high ecological diversity.Based on analyses of policy documents, I examined whether Swedish local authorities and planners take urban green spaces into consideration as potential multifunctional systems, including the maintenance of biodiversity. The result showed that Swedish planners and local decision-makers have not fully understood the multiple uses of urban green space, for example, the same area can act as a recreation area, improve the local climate, and maintain biodiversity.A normative model for conservation planning in urban landscapes was defined and operationalised by using landscape ecological principles. Urban planners were interviewed about their interest, ability, and knowledge with respect to planning for functional networks of green spaces in relation to the normative model. The unanimous view was that planners were interested in the concept of biodiversity. However, they were restricted by the extent of their knowledge, by personnel lacking suitable qualifications, and by inadequacies within their organisations. To deal with this, better integration of natural, social, and political sciences in education, as well as policy implementation should be developed.