PhD defence: Mette Boye Nielsen
Title: Maximizing Ecosystem Services in Danish Single-Family Housing Areas
Professor Gertrud Jørgensen (chairman)
Professor Anne-Karine Halvorsen Thorén, NMBU, Norge
Senior Lecturer Andy Clayden, Sheffield University, UK
Professor Marina Bergen Jensen, Department of Geosciences and Nature Resource Management, University of Copenhagen, Denmark (Nov 2012 – Jan 2015)
Senior Researcher Palle Kristoffersen, Department of Geosciences and Nature Resource Management, University of Copenhagen, Denmark (Sep 2010 – Nov 2012)
This thesis deals with sizing the present and potential ecosystem services in Danish single-family housing areas. Urbanization causes a heavy environmental footprint on Earth. Maximization of ecosystem services (ESS) in single-family housing areas may trade off some of the negative impact of cities and improve resilience to climate change. The potential for maximization depends crucially on spatial and social constraints. However, little is known about the relation between what is spatially possible and what is accepted by local residents, specifically garden owners. The purpose of this PhD thesis was to quantify both the spatial and social conditions, i.e. the potentials as well as the constraints for maximizing ecosystem services in single-family housing areas, and to shed light on how these potentials and constraints relate to urban form and garden owner characteristics.
First, a detailed GIS-based mapping of land cover was conducted in three detached single-family housing areas in Denmark of different urban form but otherwise comparable. Second, a selection of ESS was quantified based on the obtained land cover data. Third, potentials for maximizing the selected services were estimated in two scenarios; a spatial scenario based on merely spatial analysis and a socially acceptable scenario based on responses from a questionnaire. Fourth, factors related to social acceptance were explored.
The results of the thesis indicate that the current ecological performance of single-family housing areas is related to urban form. Furthermore, the results demonstrate that single-family housing areas offer a significant spatial potential for maximizing ESS, specifically in terms of on-site stormwater management, carbon storage, and habitat enhancement. However, social constraints decreased especially the potential for carbon storage and habitat enhancement. The thesis highlights spatial and social concerns that need to be considered if ESS levels in single-family housing areas are to be maximized. The results of this thesis can be used to inform urban sustainability and climate resilience strategies that target single-family housing areas.