Urban Trees : A case study in central Umeå

Abstract: Urban trees are crucial to a healthy environment. The benefits range from good air quality to storm water management and public health. The aim of this thesis was to study urban trees in Umeå city. Umeå is in a process of densification and has a vision to increase in population to 200 000 by the year 2050. During densification, trees are often removed to make space for buildings and streets. To keep track of the trees in an urban area, an analysis of the share of canopy cover can be done. For this thesis, the city enter in Umeå has been analyzed to find out the share of trees, vegetation, imposturous ground, buildings, and water that makes up the land cover. This through a canopy cover analysis using the software i-Tree Canopy. The results show that the overall share of urban trees has decreased since 2007 and the share of buildings have increased, an evident effect of densification. In addition to analyzing canopy cover, the change in amount and location of municipally owned trees has also been analyzed. This analysis presented a contradictory view of urban trees, where the number of trees has increased. A reason for this could be that while the municipality has programs in place to plant and manage trees, privately owned trees are not being monitored. There are obstacles with the aim to increase the number of urban trees in a dense city. The increasing amount of imposturous ground and building makes the environment hard for trees to thrive in. The roots have not enough space to grow, and the trees are prone to damages. This results in trees that does not live very long before they have to be removed and replaced, which has negative effect on the environment. Preserving trees with large canopies and at the same time planting new ones are important parts in keeping a sustainable urban area. Analyzing canopy cover and the change over time is a way to learn and prepare for future urban planning in Umeå.