The healing power of trees. The effect of trees on our health

We know how important our health is, and nutrition, exercise, and mental well-being play a crucial role. However, the influence of our immediate environment on our health receives less attention.
Nearly three-quarters of the German population currently lives in cities, and this number is rising. But what contributes to a health-promoting environment in our cities?

Trees! They are at the top of the list!

This is hardly surprising, but it is still exciting to examine this in more detail. Some very interesting and insightful studies look at the influence of urban trees on the health of the people who live there.

But first, some basic thoughts about trees in cities.

Trees as green oases

Trees have a calming effect on many people. This may be due to the colors: green is said to have a balancing and calming effect and trees bring this green to the center of the city.
Trees just stand there while traffic and people buzz around us. 
Trees embody a different time horizon than our everyday problems and worries. They stand there, day after day, year after year, and radiate a dignified calm.

However, trees are constantly changing, almost imperceptibly slowly, adapting to the seasons. Trees can connect us to the forces of nature, to the cycles of life, to time. Trees are small ecosystems in their own right and provide habitats for a wide variety of animals, plants and fungi. Maybe a bird is watching you from the branches, maybe the tree is covered in a layer of moss or ivy, maybe some beetles are crawling across the bark. A tree brings peace and life to the city at the same time. 

Christian Morgenstern wrote: «For me, nothing represents the world and life more than the tree. "

And trees are not only aesthetically pleasing: They provide shade, dampen noise and improve air quality. Andrew Roloff He writes that urban trees clean the air of emissions, especially by reducing ozone, nitrogen oxides, sulfur, and carbon dioxide. With increasingly higher summer temperatures, these factors will become even more important, particularly because cities are generally heat islands and expose heat-sensitive populations to health risks.

The healing power of trees has been scientifically studied

And now to the exciting research results on the effects of trees on human health:

A much-discussed Study from Toronto A statistical correlation was found between the number of street trees in a residential area and the perceived health of the people living there. Ten additional trees per city block were associated with an improvement in perceived health that statistically corresponded to approximately $10.000 more in annual income or seven years of age.

Furthermore, the study indicates that the trees achieve their greatest positive effect through their contribution to the prevention of cardiovascular diseases. The results clearly reflect that people in urban areas with more or larger trees suffer measurably less from these diseases. This is an extremely important factor for Germany, as cardiovascular diseases are the number one cause of death in this country.

The study formulates the thesis that better health - especially protection against cardiovascular diseases - can be attributed to better air quality, more physical activity and stress reduction.

Sure: Trees can improve air quality. They can also motivate people to exercise more. Maybe go shopping by bike because the street is in the shade and offers a special atmosphere because of the old trees. For this reason alone it is worth planting more trees in our cities. But reducing stress because you live in an area with more or larger trees? Yes, it looks exactly like that!  

Another interesting one Study appeared in Science, another renowned science journal. The architecture professor Roger Ulrich studied in an American clinic how the view of trees influences the recovery of patients. One group of patients had a view of trees, another group of a house wall. Ulrich comes to the conclusion that patients with a view of trees had to spend significantly less time in hospital, took less painkillers and suffered fewer postoperative complications.

There is even a term for this health-promoting effect of plants: Biophilia. The Austrian biologist Clemens Arvay describes in his book The Biophilia Effect: healing from the forest, how walks in the forest activate the natural killer cells of our immune systems and thereby strengthen our general health. Arvay goes further and describes how forest walks can prevent cancer and protect us from mental illness. His reasoning is based in part on the research results of a Japanese study, the Shinrin Yoku - also known as forest Baden - scientifically investigated. These study leaders explain the strong health aspects with our origins as humans. For most of our history we lived in a world that was shaped by trees. Contact with trees can relax us and reduce stress.   

More trees bring more health and therefore quality of life

Yes, trees are important to our health. They provide shade, improve air quality and dampen noise. They can reduce stress, and ten more trees in our neighborhood can - on average - physiologically rejuvenate us by seven years. And because almost three quarters of the German population currently lives in cities, it is crucial to bring more trees into our cities and to protect the existing trees.

Would you like more information on this topic? Here you will find a very extensive literature research from the University of Kassel.

Andrew Hunkeler
Graduated social and cultural anthropologist with a focus on sustainable and participatory green space design in cities.
My vision is to bring together: people and trees, nature and culture, population and urban authorities.
If you have any questions, suggestions, interesting stories or exciting knowledge on this topic, please feel free to write to me: andreas@andreashunkeler.com. I'm looking forward to your message!