Experience and expertise

These talks and other activities give a good impression of the experience and competence of our experts. See also the dedicated 3+30+300 website for a series of webinars and talks specifically about this principle:

• The Nature-based Therapy podcast series (for the RESONATE Horizon Europe project), various episodes hosted by Johan Östberg.
• Expanding the impact of nature-based solutions through evidence-based metrics and guidelines, talk by Cecil Konijnendijk at IV Congreso Ciudades del Futuro, Bilbao, Spain, 2025.
• KAN Café interview with Cecil Konijnendijk, about trees, cities and the 3+30+300 principle, 2025 (In Dutch).
• Keynote speech about the 3+30+300 principle by Cecil Konijnendijk, AGM of the European Arboricultural Council, Bonn, 2025.
• Episode of the Tree Lady Talks podcast series on the 3+30+300 principle, hosted by Sharon Durdant-Hollamby, with Dirk Voets and Cecil Konijnendijk, 2024.
• Greening our Cities: the 3:30:300 rule for urban harmony. Cecil’s talk at TEDx Varese, Varese, 2023.
• Leadership in urban forestry and urban design. Podcast hosted by NBSI as part of the European Forum on Urban Forestry 2021.
• Episode of Tree Lady Talks podcast series on nature-based solutions, hosted by Sharon Durdant-Hollamby, with Johan Östberg and Cecil Konijnendijk, 2020.
• Urban forests a nature-based solutions. Cecil is featured in an episode of the CNBC Sustainable Energy series, on urban forests as nature-based solutions, 2020
• How do we create ‘sylvan cities’? Cecil’s keynote on ‘sylvan cities’ at the IUFRO World Congress 2014 in Salt Lake City, USA.

Our customers and partners have included, among other, Breekijzer (Belgium), BUUR part of Sweco (Belgium), the Department of Environment of the Flemish government (Belgium), Department of Architecture, Catholic University of Leuven (Belgium), Interleuven (Belgium), Province of Limburg (Belgium), Claerhout Communicatiehuis (Belgium), School of Landscape Architecture, Beijing Forestry University (China), Danish Landscape Architecture Association (Denmark), Danske Park og Naturforvaltere (Denmark), Department of Geosciences and Natural Resource Management, University of Copenhagen (Denmark), the European Forest Institute (Finland), ERSAF and ETIFOR (Italy, for EU Erasmus+ project UFOREST), Academie van de Bouwkunst Amsterdam (Netherlands), Cobra Groeninzicht (Netherlands), Landscape Architecture at TU Delft (Netherlands), Felixx Landscape (Netherlands), IVN Natuureducatie (Netherlands), Municipality of Alphen aan den Rijn (Netherlands), Norminstituut Bomen (Netherlands), Pius Floris Boomverzorging and Advies, including for urban forest plans in Barneveld and Groningen (Netherlands), Rotterdamse Academie van Bouwkunst (Netherlands), Schipper Bosch (Netherlands), Stadswerk (Netherlands), Stichting Steenbreek (Netherlands), Terra Nostra (Utrecht tree management strategy) (Netherlands), TFI Vitaler Groen (Netherlands), University of Applied Sciences Van Hall-Larenstein (Netherlands), Karachi community urban forest alliance (Pakistan), Institute for Spatial Policies (Slovenia), the municipality of Mataró (Spain), City of Malmo (Sweden), Dacapo Mariestad (Sweden), Stockholm Forest Cemetery administration (Sweden), the National Board of Housing, Building and Planning (Sweden) – for the Nordic Council of Ministers, Movium – Swedish University of Agricultural Sciences (Sweden), City of Birmingham and Birmingham Tree People, Future Woodlands Scotland (UK), Trees for Cities (UK), the Woodland Trust (UK), Federal Department for the Environment (Switzerland), American Society of Consulting Arborists (USA), Arbor Day Foundation (USA), PlanIT Geo (USA), the Trella Group (USA), European COST Action Urban Tree Guard, the International Society of Arboriculture (and its different chapters) (USA), and the United Nations Economic Commission for Europe (forest program).

We have a partnership with Treeconomics (UK) as well as with SYLVA: Atelier for Urban Forestry and Landscape Architecture (Netherlands). We are a partner in the Horizon Europe research projects eco2adapt and Resonate (workpackage resp. task lead) – and we contributed (on behalf of FAO) to the CONEXUS project. We also participated in the Erasmus+ Knowledge Alliance project Uforest. Johan Östberg was an active member in the Urban3Guard COST Action. For this COST Action we organised a training school on nature-based solutions and biosecurity. We were a partner in the Yggdrasil – The Living Nordic City project funded by the Nordic Council of Ministers and led by our colleagues at Trädkontoret. In 2026 we start a new project for the Nordic Council, titled NORD-LOCAL-NbS (on implementing nature-based solutions), also headed by Trädkontoret in Sweden.

Our current projects focus, among other, on: development of urban forest strategies; assessing and integrating the health benefits of urban green and blue space; development of guidelines and standards for urban forestry; enhancing entrepreneurship in urban forestry; reviewing the benefits of urban trees; urban forest inventories; building forest resilience; developing and testing nature-based therapies; workshops and training; and conference organisation and facilitation.

NBSI supports the European Forum on Urban Forestry. We also co-host the Urban Tree Diversity conference, with its most recent, 5th edition having been held in Madrid, Spain, and a 6th edition is scheduled for October 2026. Cecil Konijnendijk is a board member of the Nationaal Dakenplan (National Roof Plan) foundation in the Netherlands. Together with Trella, we co-hosted the online conference ‘Reimagining Future Cities – The Green Way’ on March 22, 2021. The full recording of this event is available here.