Framtidens stadsträd för en fungerande grönstruktur

Abstract: The effect of climate change places demands on how we build cities. Cities have to be built denser to meet the objectives of sustainability but as a result of this densification city green areas are at risk of exploitationand disappearing. The question this raises is whether there has to be an opposition between a dense and a green city?Urban trees are playing a very important role in cities. They stand as the major part of the vegetation in citieswhich are otherwise dominated with concrete and stone. In this master thesis the part played by trees in cities is investigated. The thesis also examines how urban conditions affect trees and how their qualities can give an extra value for example by, local disposal of stormwater, reducing carbon dioxide and benefits to wildlife.A list of trees for present and future urban areas in the Stockholm region has been created. The list contains the parameters which describe the characteristics of the trees such as; tolerance to air pollution, salt resistance, carbon absorption, allergies and the importance for animals.I explain the word biodiversity and the importance of biological diversity and dispersal in urban areas. Termsof biological dispersal are illustrated and explained together with different theories of urban dispersal.Strategies for promoting biodiversity in planning and in management are pointed out.A questionnaire survey has been sent out to all local authority offices in charge of city planning and/or theenvironment in the region of Stockholm. The purpose of the questionnaire was to get a picture of how much the local authorities are working with biological dispersal in urban areas, selection of urban trees, multifunctionalvegetation and compact cities versus biological diversity. A summary has been made in which I comment on the answers I got from the survey.Finally an application of a dispsersal theory has been made in a part of Stockholm with a subsequent discussion of the models consequences for biological dispersal.