Foreword

Yggdrasil – The Living Nordic City (the Yggdrasil project in short), launched under the Nordic Council of Ministers’ Vision 2030 initiative, set out to contribute toward making the Nordic Region the most sustainable and integrated region in the world. As part of the broader Nordic Cities Nature-Based Solutions Programme, Yggdrasil has aimed to strengthen the role of urban trees and green spaces in creating healthier, more climate-resilient cities. It emphasises the unique Nordic perspective, building upon our region’s strong tradition of environmental stewardship and community-focused urban planning.

The current growing interest in urban trees and green spaces reflects a broader recognition of their vital role in addressing critical challenges such as public health, climate adaptation, and biodiversity loss. Cities and municipalities across the Nordic region are increasingly embracing nature-based solutions which harness the power of natural ecosystems to tackle urban challenges. The Yggdrasil project contributes to this movement by establishing a collaborative network of Nordic cities, where municipalities can share ideas, experiences, and strategies for incorporating trees and green spaces into urban environments.

At the heart of the project has been the evaluation and implementation of the 3+30+300 rule, a greening principle that has gained prominence since its introduction in early 2021. This guideline promotes a healthier urban environment by advocating that every resident should be able to see at least three mature trees from their home, live in a neighbourhood with no less than 30% tree canopy cover, and have access to a green space within 300 metres. For the first time, a Nordic assessment has been undertaken to see how well Nordic cities are fulfilling this principle and how it can be adapted to the distinct local contexts across the region and adapted more widely.

The project highlights the importance of evidence-based guidelines to support governance, planning, design and monitoring. Through its evaluation of the 3+30+300 principle Yggdrasil offers a nuanced approach that respects local conditions and needs. By integrating research with practical applications, the project provides Nordic cities with the tools they need to make strategic decisions about urban greening, climate adaptation, and public health. Obviously, the involvement of municipalities in this work is therefore crucial and we are very grateful to the participating Nordic cities, Bergen and Stavanger in Norway, Tampere and Turku in Finland, Malmö and Umeå in Sweden, Kolding and Holbæk in Denmark, and Reykjavik in Iceland, for their active contributions during the workshops, sharing of data and other information, and other contributions throughout the project.

We also would like to thank the members of our advisory board for their support and important advice: Ulrika Åkerlund (formerly Boverket, now Movium, Sweden), Matthew Browning (Clemson University, United States),  Pernilla Johansson (Trädkontoret, formerly, e.g., chair of Sveriges Stadsträdgårdsmästare, Sweden), Kjell Nilsson (owner of Nilsson Landscape, formerly among other Director of Nordregio, Sweden), Ben Somers (professor, Catholic University of Leuven, Belgium), Jessica Svännel (Region of Gotland, Sweden). These members represent a wealth of experience in Nordic and international green space policy, practice, and research and they have given us valuable insights that have strengthened the whole project. We are also grateful to Karin Sandberg, County Board (Länsstyrelsen) of Västmanland for her review of tree biodiversity aspects of this project.

As we move forward, the lessons learned from Yggdrasil will serve as a foundation for future projects and initiatives, fostering greater cooperation among Nordic cities and reinforcing the region's leadership in sustainable urban development. Through the collective efforts of policymakers, researchers, practitioners, and local communities, the Yggdrasil project will help create greener, healthier, and more resilient cities across the Nordic region.