There is a painting in the NSW Art Gallery that sums up the summer in Sydney for me. It's Albert Hanson's Pacific Beaches (1898): a deserted Sydney beach in the late afternoon, the west sun hitting the distant sandstone cliff. It is scorching, with a breeze that barely shivers the water, but we are in the shade looking out from a cool spot under the trees. I look at the photo and feel my breathing slow and my shoulders relax. Is it just so good to be on the beach in the shade when the sun is hot enough to foam your skin?
Certainly shade is one of the great benefits of trees to human health. Researchers estimate that trees lower the temperature by at least six and up to 20 degrees. And it is not the only health benefit. Trees also boost immune function and lower blood pressure thanks to the beneficial bacteria and phytochemicals that are released by trees or that live in your arms.
Much of the initial research setting the rationale for tree-related well-being was carried out in Japan, where the "bath in the forest", shinrin-yoku, is something a health professional can advise to add to his or her health routine . The bath in the forest is a walk through the trees (we could call it hiking in the bush) with the Fitbit turned off and the focus shifted from itself to the world. As you might expect from a country that officially ranks its gardens and its sunset observation points, there are designated "forest bath" sites throughout Japan.
It turns out you do not even have to walk through trees to share their benefits against stress. The appearance is sufficient even in a photo. The theory that explains how this can work is called "fractal fluency." Fractals are patterns that are repeated through scales – like a tree branching from the trunk, and continuing to branch, to the branches and the leaf structure. Researchers developed the theory by trying to understand why viewers had a positive physiological response when looking at a Jackson Pollock painting, but not when they looked at a fake Pollock. Pollock's painting is fractal, fakes were not.
Fractals are everywhere in nature and our visual system has evolved to process the fractals with ease. As a result, looking at the fractals makes us feel good, to the sound of a 60% reduction in biological stress measures. After I read this research, I had another look at Hanson Pacific Beaches; for sure the trees that display the view are fractals.
Research suggests that you need a few minutes looking at the trees or for photos of trees to start getting the benefits that relieve stress. Then, by all means, slow down and smell the roses, but do not forget to look at the trees, or better yet, to bathe in them.