Skip to content

“We need trees. They are just as important as housing, streets or shops.”

Yosr Hmam Spit

Cecil Konijnendijk is a scientist specialising in urban forestry. The United Nations and governments in more than 30 countries value his expertise. He is currently achieving great success with his 3-30-300 rule, which is considered a democratic tool for more green space in the city. In an interview with the Lichtung, he talks about his 25-year journey around the world and which urban projects he finds most exciting at the moment.

Lichtung: You lived in Barcelona. How are Spanish cities caring for trees in times of drought? Maybe you can tell us about how Spanish cities are adapting to climate change?

Cecil Konijnendijk: In Spanish cities people have had to think about temperatures and drought for many years already. They are pretty good in selecting the right tree species and adapting to climate change. Interesting enough, I think they do better than Vancouver or Zeist (Netherlands), places where I have also lived. There we have more problems with climate change. In Vancouver for example they had really hot summers during recent years which meant a lot of trees where dying, because they have selected the wrong tree species. In some ways the Mediterranean cities are more used to the heat and they are maybe more adapted to using the right tree species.

Lichtung: We read, that the USA and Canada have a long history in urban forestry, longer than in Europe, where the ‘Stadtwald’ or city forests are better known. Could you possibly explain the differences with a few keywords?

CK: When we in Europe say urban forestry, then people still think about forests. In North America it started with street trees, they called it shade trees. It is a different starting point. Now these two traditions are kind of merging, so now when we say urban forestry, we mean all the trees in urban areas including the forest like the Wienerwald. So it is the whole forest system of a city basically. They came from different backgrounds, but today we are closer to each other.

Lichtung: There are often gaps or misunderstandings between urban foresters and classical foresters. What could they learn from each other? What could promote the empathy?

CK: I was trained as a forester and when I started in urban forestry, many foresters were thinking I was a bit funny. Today urban forestry is more accepted.  I always say urban forestry really can learn from forestry in terms of the sustainability perspective, the longterm thinking, not to think just in 4 or 5 years, but in 100 years. Forestry has very detailed inventory and resource management approaches, so I think that is really useful for urban forestry. Forestry can also learn from urban forestry. Urban norms and values are so important, so they impact forestry. There are more demands on recreation, more demands on climate adaptation. I think foresters can learn from that. Cities are already warmer, so a lot of climate change issues and impacts on trees that will later on come to forests in rural areas are happing already in cities. This is why cities are a bit of a test pad for forestry in general.

Lichtung: You designed the 3-30-300 rule. What are the three main obstacles implementing the rule?

CK: Seeing green, living in green and using green, that is basically the idea. It is based on research, so we know that specially the ‘30 % tree canopy in every neighbourhood’ and the ‘300 metres to the next green space’ rules are supported by research on health promotion. We know that the state of public health would be better and also climate adaptation more successful, especially the cooling effect. I introduced it also in order to break the disciplinary silos and connect science, policy, practice and the public. It raises the importance of trees and green spaces in the city to politicians, planners, architects, engineers, but also to communities and citizens alike. And I really think it is successful there, because many people now know it and talk about it. But there are also the obstacles as you say. One obstacle is the space. It is hard to find enough space for trees in the cities. There is no space above but also underground space, because there are so many cables and sewage systems and infrastructure. The second problem is I think that city trees are often dying at a very young age. When we plant a tree in a city it lives only for 20 or 30 years. Many of the ecosystem services only come after 30, 40, 50 years. So we need to become better in caring for trees. The third obstacle you already mentioned is politics. Trees are often not the first priority. Instead, economic development, construction sector and building housing are higher on the agenda. Therefore I think we need a change of priorities when we say we need nature in the city. We need trees. They are just as important as housing, streets or shops.

Lichtung: I am curious if you found evidence between wealth and willingness to make cities and landscapes greener?

CK: That is a really important point. We know in general that if people are wealthier they are more willing to do work on green spaces and plant more trees. In many cities you see the most tree cover, the best parks in the rich areas. People take more care of them. They are lobbying with the politicians. The poor people really need it but often they do not have the same accessibility. So this is also a motivation for 3-30-300 that everybody should get access to green space. The rule is also a democratic tool for accessibility. Any basic service should provide green and trees, it is good for our health, for climate and anybody should have access. Not only the people who have a lot of money.

Lichtung: Could you give us two best practice models for innovative urban forestry, one in Europe and one worldwide?

CK: I think probably the best model I know is in Singapore. They have really integrated greening urban forestry into every policy area basically. Every building has to be green now. They have all those big gardens. They think about tourism, they think about economic development. They really integrated urban forestry in planning and developing the city. So many people think about Singapore the best practice model worldwide, of course they have a lot of money. Berlin has been doing really interesting things. They use a wild nature approach. So they let nature go wilder, they don’t always manage everything. And people accept it. They have areas like Naturpark Südgelände, the Tempelhofer Feld, they are kind of natural areas that bring nature into the city. So people are used to have wilder nature nearby. For me that is very innovative. Less managed green space, more wild green space.

Lichtung: Green spaces promote peace in society since it is a recreational area that enables for all people to recover from stress. However, parks are often perceived as unsafe spaces, particularly for women. How can gendersensitve design of urban forests help in this?

CK: On the one hand as you say it is great to bring nature back on the other hand there are problems with feeling unsafe. The research shows that it is really important to have good stewards in the park. Their presence results in a kind of social control effect which prevents violence or crime. It is really important to design green spaces together with the users, for example with women, ethnic minorities, children. I am really inspired by the work done in Barcelona and in Malmö. They called it feminist planning. This is a collective of female planners who are actually planning the city. So far, cities have been planned by men for men mostly, and I think we have to really change that. We have to think how women are moving in the city. How can teenage girls for example feel safe and therefore meet each other in public green spaces, have fun together, relax, do sports, learn and connect with nature? There are new approaches to design now, we have to really step away from this kind of male dominated perspective on planning cities and green spaces.

Lichtung: In Vienna we’ve got a kind of super-plant in urban forestry: the European hackberry. Recently the most popular one is Acer platanoides. Do you have a kind of super plant with which you are working a lot?

CK: Actually the European hackberry was also very popular in Barcelona. It is a big share of the street trees, so I know it well. What really makes a species a super-species depends a bit on where you are located. London plane tree (Platanus hispanica) is still very popular. Many cities use it. It is very resistant to pollution. Also, the ginkgo tree has become very popular, because it is very resilient and it has nice colours. I think people are looking for new street trees like for example Zelkova that comes more and more into our cities. So there are a few super trees, for sure. Acer platanoides is another one which you can see everywhere, but they are sometimes a bit too aggressive.

Lichtung: This perfectly leads to our next question: how about biodiversity in cities and how is it connected with urban forestry?

CK: This is really important. In general, if you have more biodiversity, you build more resilience, more resistance to pest and diseases. There is actually a guideline which is developed a few decades ago in the United States by Dr Frank Santamour that says 10-20-30. You should not have more than 10 percent of the same species, not more than 20 percent of the same genus and not more than 30 percent of the same family of trees. In that sense you will build biodiversity. I personally like biodiversity on the same street. I have seen the mixing in Berlin and in other cities, where you have two or three species in a street instead of only one species.

Lichtung: How deep should the public be involved in managing urban trees?

CK: I think an app could be handy to involve people. When it gets really hot in the summer, maybe people who are living in the street, could help watering the trees. People could also help spotting pests, diseases. If there is a new pest coming they could help and have a look and also could check, if trees are doing okay.

Lichtung: How did you realize that nature is important for us and what is your favourite tree species?

CK: I come from a small village in the southwestern Netherlands, close to Rotterdam. I grew up in the countryside in an open area with not that many trees. But my parents took me and my brothers to the coastal forests on Sundays. In the holidays we often went to forests in the centre of the Netherlands, to Germany or Belgium. That started building the interest and maybe also understanding the need for nature in our lives. My brothers are doing the same thing with their families now. It is a kind of family tradition. In terms of my favourite landscape – I like the forest both closed and open forests, but I also like the open land with big skies and the seaside because I grew up close to it.  My personal favourite tree species are Oak because of its size and its long history as well as the male Ginkgo which is a really good urban tree because of its resilience.

About the person

Cecil Konijnendijk studied forestry in the Netherlands. After 25 years of scientific research in Finland, Denmark, Sweden, Hong Kong, Vancouver and Barcelona, he recently got back to the Netherlands. His work has been featured by leading media outlets such as CNBC and in international documentary films. Cecil helped founding the academic journal Urban Forestry & Urban Greening, and edited textbooks such as The Routledge Handbook of Urban Forestry. He is Editor-in-chief of Arboriculture and Urban Forestry, the scientific journal of the International Society of Arboriculture.

Nature Based Solutions Institute:

Participation: Christine Ornetsmüller

Leaves of a Ginkgo Tree in Autmn