In the woods, we return to reason and faith. There
I feel that nothing can befall me in life—no disgrace,
no calamity … which nature cannot repair. Standing
on the bare ground, my head bathed by the blithe
air, and uplifted into infinite space … the currents of
the Universal Being circulate through me.
Ralph Waldo Emerson, Nature (1836)
THE PROVEN HEALTH BENEFITS OF TIME WITH TREES
Any walk outdoors is good for you, but if you can get to some woods, that’s even better. Over the past few years, more people have become intrigued by the concept of forest bathing—healing through the contemplative practice of intentionally spending time with trees—and it has really caught on. Forest bathing is being taught and practiced at botanic gardens, spas, spiritual retreats, and recreation centers. Beyond that, it is being used in psychiatric hospitals, in conjunction with physical therapy, and in addiction treatment programs.
As humans, we are drawn to trees. It’s an innate tendency, and something powerful happens to us when we are near them. A love of trees transcends borders and cultures. Many people respond with delight to a mention of trees, and many will describe a special tree or a meaningful or even profound experience involving one. In his wildly popular book Forest Bathing: How Trees Can Help You Find Health and Happiness (2018), Dr. Qing Li explains that there is a Japanese word for that indescribable feeling: yūgen, meaning “deep” and “mysterious.” In the Japanese system of aesthetics, it is understood as a profound and sometimes poignant wonder at the beauty of the universe. A passage by the thirteenth-century Japanese poet Kamo no Chōmei evokes this idea elegantly: “It is similar to an autumn evening under a colorless, quiet sky. Somehow, as if for a reason we cannot quite recall, tears well irrepressibly.”
Yūgen is one of many reasons that forest bathing has caught on, but there are more: It is a lovely way to pass the time in nature; it is a way to connect to the spiritual without dogma; and, of course, most humans like trees. If that weren’t enough, there is also a scientific explanation for how and why forest bathing makes us feel so good.
About forest bathing
In 1982, Tomohide Akiyama, then secretary of Japan’s Ministry of Agriculture, Forestry, and Fisheries, coined the term shinrin-yoku. This translates as “forest bathing,” and can be defined as making contact with and being affected—both physically and mentally—by the atmosphere of the forest. Perhaps more aptly called forest basking, since neither soap nor tub is involved, forest bathing can be experienced as a type of meditation, and, just as with other Eastern-rooted practices such as mindfulness, Ayurvedic medicine, and yoga, Westerners are learning that there is far more to meditation than simply becoming calm. Many authorities are in agreement that meditation can ease psychological problems from anxiety to post-traumatic stress disorder, help to treat addiction, make us better parents and workers, and promote the healing of many physical ailments.
Forest bathing incorporates many of the benefits of meditation while getting us outdoors and in motion. In a recent study conducted by the College of Landscape Architecture at Sichuan Agricultural University, Chengdu, China, thirty men and thirty women were given a route of the same length to walk in either a bamboo forest or an urban area. The results showed that, although walking is good for you, walking among trees is much better.1 The researchers measured blood pressure as well as electrical activity in the brain using an EEG (electroencephalogram), and they found that, among those who walked the forest path, blood pressure was lowered significantly as attention and concentration improved. The people walking in nature reported less anxiety and a generally happier mood than the urban group.
Forest bathing has an impact on even more than mood and blood pressure. The New York State Department of Environmental Conservation and myriad other sources maintain that the simple act of intentional, attentive time with trees:
• Decreases fatigue;
• Has immune-system boosting, antiviral, and even anti-carcinogenic benefits;
• Increases the ability to focus, even in children with attention-deficit hyperactivity disorder (ADHD);
• Speeds up recovery from surgery or illness;
• Regulates the endocrine (hormonal) system;
• Lowers blood glucose, affecting obesity and diabetes;
• Enhances the ability to relax and get a better night’s sleep;
• Increases energy;
• Has been shown to increase brainwave activity in young adults and positively affect elderly patients with chronic heart failure.2
Imagine if a pharmaceutical company could produce one pill that was capable of doing all that!
Forest bathing is an active process, not just a matter of being near trees as static objects. Many species, including pine, yew, hop hornbeam, and sugi, emit biochemicals called phytoncides that interact with our central nervous system and have calming, anesthetic qualities, even anti-carcinogenic properties. Phytoncides are pungent essential oils, antimicrobial volatile organic compounds. When you are breathing in the heady fragrance of pine or cedar, you are inhaling phytoncides. They have been proven to boost the trees’ health as well as our immune systems, which is a powerful thing, but that’s not the only benefit of forest bathing.
Phytoncides contain terpenes (like those in cannabidiol, CBD, a chemical compound found in marijuana oil) that can stimulate immunity and anti-cancer proteins in our bodies, fight viruses, and increase the release of the steroid hormone dehydroepiandrosterone (DHEA) into the blood, protecting and even strengthening our hearts. They also activate the vagus nerve (see page 26), reduce our production of the stress hormone cortisol,3 (making us more calm and focused), and likely decrease inflammation, as well.
As trees emit, they also absorb. According to the German forester and writer Peter Wohlleben in The Hidden Life of Trees (2015), trees act as natural air purifiers, not unlike houseplants. Trees take in pollutants such as nitrogen oxide, ammonia, sulfur dioxide, and ozone through their leaves. That’s part of why we feel better when we go for a walk in the woods. Breathing cleaner air is not just a pleasant experience; it can reduce the symptoms of asthma, make exercise more efficient because we don’t have to work as hard to take in oxygen, and perhaps even mildly cleanse our organs.
Hearing trees
It has been scientifically proven that trees emit not just an aerosol of healing phytocides, but also beneficial sounds. We’ve all heard branches groan in a storm and the susurration or whispering of leaves as they move together in an afternoon breeze, but plants (and trees in particular) also emit vibrations that can be measured using microphones and ultrasonic sensors. In an interview with Yale Environment 360 in 2017, the biologist David George Haskell explained that:
an ultrasonic detector applied to a tree, particularly in the summertime, reveals how as the morning passes into afternoon, the tree goes from a state of full hydration to a place of distress, where there are all sorts of little ultrasonic clicks and fizzles emerging from the inside of the tree as water columns break, as the tree becomes more dried out. By applying an ultrasonic sensor, the tree suddenly has its inner life revealed.4
Amazing!
Just as trees respond to increases and decreases in light and temperature, they also respond to sound via vibrations. For example, urban trees tend to grow thicker bark as a reaction to the shaking and pulsation of passing traffic. There are also hypotheses that trees use sounds to communicate with one another. In an interview in Smithsonian magazine, Wohlleben calls this the “wood-wide web”: the connection among trees in a healthy forest, whereby nutrients and water are shared and information sent by means of a symbiotic relationship underground, between microscopic filaments at the tips of tree roots and fungi—called mycorrhizal networks—to signal threats such as drought or insect infestation.5
If trees can emit vibrations, it follows that human beings can pick them up, even if only on a very subtle level. Maybe there is something to treehugging after all? I spoke to several proponents of forest bathing who say that it is those vibrations that can cure headaches more quickly and naturally than taking an analgesic. I haven’t had that experience, but I do know that when my thoughts are unsettled, if I sit with the silver maple in my backyard I feel better. Is it the vibrations, the terpenes, the green of the leaves, or the pause to reflect on something that has endured more than a hundred years of blizzards, thunderstorms, and heatwaves? I’m not sure, but I know it heals me in a unique way.
We can’t all get to the woods, but fortunately, as we’ve already seen, there are health benefits to even a little bit of nature. A park, a tree-lined road, or a couple of trees in a backyard or courtyard can help.
Urban planners and environmental scientists are taking the benefits of forest bathing to heart and working to create more effective green spaces. One initiative is City Tree, which isn’t a tree at all, but rather a structure built from mosses that bind with toxins and particulates to clean the air.6 It looks a bit like a giant television, but instead of a flat screen, a huge patch of moss covers the vertical surface. Not only does the moss clean the air, but also, because it stores a considerable amount of moisture, it cools the area around it.
Projects to plant (real) city trees are cropping up all over the world as urban planners learn more and more about the power of green. The MillionTreesNYC initiative was launched by the New York City Parks Department in 2007, and the project’s goal was achieved in 2015. A million street trees were planted throughout the city over a period of eight years. As part of the scheme, the non-profit New York Restoration Project targeted neighborhoods that needed trees, and sought out public and private funding to provide them. Other cities, including London, Shanghai, Denver, and Los Angeles, have developed similar programs, and the results are all good—from cheering up neighborhoods to raising property values to filtering air and decreasing noise pollution.
Finding the right trees
It is important to note that not all forests are rich in phytoncides. Wohlleben points out that when spruce and pine trees are introduced to places where they’re not indigenous, the trees suffer, dry out, and create excess dust, making us less, not more, healthy, so be aware when seeking out a forest to walk in or planting trees.
FOREST BATHING: STEP BY STEP, TREE BY TREE
So, how does one go about forest bathing?
1. You need only the most basic equipment: walking shoes and insect repellent. Leave your camera, your journal, and your guidebooks behind, and turn off your mobile devices. Forest bathing is about being, not analyzing.
2. Find some trees. This can be a forest of ancient pine or a copse of paper birch, or, if you’re like me, a single silver maple in your backyard. Of course, spending more time with more trees is better, because the effect is multiplied—studies have shown that spending three days and two nights in a thickly wooded area will improve the function of the immune system for up to seven days—but do the best you can. A little forest bathing is better than none, and there are benefits to it even if you can’t take in a huge lungful of phytoncides.
3. Find somewhere to sit or lean, where you can be still for ten or twenty minutes or more without being in the way of bicycle traffic, ants, or poison ivy.
4. Now do just that—be still. Be aware of your breath, but don’t force it. Let the experience come to you, don’t analyze. See what you see, hear what you hear, smell what you smell, feel what you feel. Light through the leaves … skittering or birdsong … blossom or decay … calm or grounded …
5. As you walk home, check in with yourself. Do you notice any changes in your body? How about your state of mind? What can you take from your forest bathing experience back to your daily life? Do you feel more optimistic? More serene? How is that headache?
6. Repeat as often as possible, and pay attention to any improvement in your wellbeing. Try a new spot next time, or focus on another kind of tree, and note the difference. (Having said that, forest bathing with the same trees in the same spot will vary every time, depending on the season, the weather, the time of day, and what you bring to the experience.)
Perhaps as you do this you will think about these powerful lines from Haskell’s book The Songs of Trees (2017):
We’re all—trees, humans, insects, birds, bacteria—pluralities. Life is embodied network. These living networks are not places of omnibenevolent Oneness. Instead, they are where ecological and evolutionary tensions between cooperation and conflict are negotiated and resolved. These struggles often result not in the evolution of stronger, more disconnected selves but in the dissolution of the self into relationship. Because life is network, there is no “nature” or “environment,” separate and apart from humans. We are part of the community of life, composed of relationships with “others,” so the human/nature duality that lives near the heart of many philosophies is, from a biological perspective, illusory.7
