Forest Walking

Discovering the Trees and Woodlands of North America

Peter Wohlleben, Jane Billinghurst

• Publisher: Greystone Books
• Year: 2022
• ISBN:
  9781771643320
• Topic: Biological Sciences
• Subtopic: Botany
• Index: Biological Sciences

Awaken your senses and make the most out of your next walk in the woods—with Peter Wohlleben, New York Times -bestselling author of The Hidden Life of Trees. "This book will fast-track you into the joys of spending time amongst the trees."—Tristan Gooley, author of The Lost Art of Reading Nature's Signs and How to Read Water "You'll be changed after reading this fine and enchanting book."—Richard Louv, author of Our Wild Calling and Last Child in the Woods When you walk in the woods, do you use all five senses to explore your surroundings? For most of us, the answer is no—but when we do, a walk in the woods can go from pleasant to immersive and restorative. Forest Walking teaches you how to engage with the forest by decoding nature's signs and awakening to the ancient past and thrilling present of the ecosystem around you.

• What can you learn by following the spread of a root, by tasting the tip of a branch, by searching out that bitter almond smell?
• What creatures can be found in a stream if you turn over a rock—and what is the best way to cross a forest stream, anyway?
• How can you understand a forest's history by the feel of the path underfoot, the scars on the trees along the trail, or the play of sunlight through the branches?
• How can we safely explore the forest at night?
• What activities can we use to engage children with the forest?

Throughout Forest Walking, the authors share experiences and observations from visiting forests across North America: from the rainforests and redwoods of the west coast to the towering white pines of the east, and down to the cypress swamps of the south and up to the boreal forests of the north.With Forest Walking, German forester Peter Wohlleben teams up with his longtime editor, Jane Billinghurst, as the two write their first book together, and the result is nothing short of spectacular. Together, they will teach you how to listen to what the forest is saying, no matter where you live or which trees you plan to visit next.

~ 1 ~ Total Immersion

AS SOON AS YOU step into a forest, you step into a different space. Depending on the type of forest, the trees may be growing together so closely that their tops almost touch. Outside, the sun may be shining brightly, but here, you are in the shade. The leaves are busily absorbing sunlight to make food. What little light makes it through the canopy is mostly green, so it feels as though you are slipping into an underwater world.

The forest is refreshingly cool. Years of discarded leaves and needles have turned the ground into a huge sponge that absorbs rainwater as it drips through the leaves and then slowly releases it into the forest floor. Above ground, you breathe in damp air, while below ground, the trees tap into the pockets of moisture captured by their maze of roots after the last rains fell. Fallen branches and trunks lie strewn on the forest floor. Rain-saturated rotting wood and downed logs steam as the sun hits them. The trees, both living and dead, are actively creating the cool, shady, moist conditions they most enjoy.

Let your eyes adjust to the quality of light around you and listen as the breeze brushes through the branches. It sounds like traffic on a distant highway, water cascading over rocks, or waves breaking on the shore. Individual trees creak and groan as they rub against one another, each producing a slightly different sound depending on how slowly or quickly, how densely or airily their wood has grown. You might even hear a hollow tree humming as though it’s experimenting with the beginnings of a tune.

Leaves and needles whisper and sing. Dry leaves hanging on young beeches chatter in the brisk spring air while they wait for the larger trees in the forest to leaf out. Unfolded aspen leaves produce a muffled muttering as the breeze turns them one way and then the other. The stems of most leaves are round to keep the tops of the leaves oriented to the sun, but the stems of aspen leaves are flat, allowing the leaves to twist in the wind so both sides can bathe in the light. Vortices of air form around and detach from the tips of conifer needles, producing a melodic chorus—known in Japanese as matsukase or the “song of the pines”—that varies in pitch as the breeze builds and dies. Small branches buffeted against one another twang like wire strung taut between fence posts. On a hot day, the popping of pinecones opening and ejecting their seeds punctuates this symphony of sound.

If you are one of those people who has trouble slowing down to listen, you might pick up on the soundtrack of the forest when something quite different draws your attention. As Jane took photographs of a particularly pleasing pattern of lichens on bark in Big Thicket National Preserve in Texas, she heard a rustling. Quite a loud rustling, it seemed to her, but when she investigated, she discovered it came from a small brown grasshopper perfectly blended into the leaf litter below. If she had not been stopped and silent at that moment, she would never have noticed it, even though it was right at her feet. It froze as she bent down to inspect it. Jane is no entomologist, so she had no idea what kind of grasshopper it was, but a search back home revealed it to be the delightfully named “mischievous bird grasshopper”—also known, somewhat less delightfully, as the Carolina locust.

As humans, we rely heavily on visual images and are not particularly skilled at interpreting sounds, especially in unfamiliar territory. In forests where bears are about, birds scratching in leaf litter can sound especially large and menacing. Later in her trip, Jane, who lives in the Pacific Northwest, heard a quiet mewing sound in Highlands Hammock State Park near Sebring, Florida, and became convinced it must be a panther kitten calling for its mother. It turned out to be a gray squirrel hiding behind a branch. A mysterious nocturnal scuffling around her campsite in Paynes Prairie Preserve State Park just south of Gainesville revealed itself in the comforting light of morning to have been an armadillo snuffling for insects in the thick layer of leaves under the live oaks.

Because we rely so heavily on sight, the merest flicker of movement quickly commands our attention even if an animal is being as quiet as it can be. In the beech-magnolia forests of southern Texas and the baldcypress swamps of northern Florida, these movements often come from green anoles scattering at the sound of your approach. Jane watched one skittering across a boardwalk in the Okefenokee Swamp Park in Georgia. On the boardwalk it was a dull brown, but as soon as it reached the grassy vegetation on the other side, it turned a bright, almost luminous, green. She had witnessed the so-called American chameleon in action.

Stopping to listen hones your senses until even stationary patterns register: a black-and-yellow salamander by the side of the trail, an orb-weaver spider suspended between branches (careful you don’t walk into its web), a striped chipmunk standing on guard next to a small crevice at the base of a tree. As you walk through the forest, many eyes will be watching you. If you take the time to stop and listen, every once in a while, you might discover some of the creatures that have you in their sights.

While you’re standing there, taking in the forest, close your eyes. Smell is not exactly our strongest sense, but we become more aware of smells when we are not distracted by what we can see. Some of the aromas you are detecting are being produced by trees as they pass chemical messages amongst themselves. What kind of messages might these be?

Trees, as you have probably noticed, cannot run from danger, so they have other ways of defending themselves. You might get a whiff of a cyanide compound in black cherry bark that smells like bitter almonds. This warning scent lets browsers know not to mess with this tree.

Oaks go even further, using airborne messages to summon reinforcements that help them combat pests. When caterpillars start munching on them, the trees pump bitter tannins into their leaves. They also send chemical messages over the air waves. Parasitic wasps fly in when they receive the oaks’ airborne invitations and lay their eggs in the caterpillars. When the eggs hatch, the wasp larvae eat their way out of their hosts, putting an end to the caterpillar buffet.

In a coniferous forest, you will pick up on that piney scent so popular with companies that make room and car deodorizers. It smells like a mixture of sap, candied orange peel, and sugar. It reminds me of summer holidays spent on the coast of the Mediterranean where the pines smell just the same. Many conifers native to northern climes suffer when they are planted in lower latitudes where the weather is too hot and dry for them. When conifers don’t have enough to drink, they become stressed because lack of moisture weakens their defenses against bark beetles. They release olfactory alarm signals to warn their companions, and these are the tangy scents that smell so strongly of beach vacations (to me, anyway).

These piney scents come from bitter-tasting essential oils called “terpenes.” In spring, pines pump more terpenes into the tender new growth deer prefer to eat and less to old growth that deer tend to avoid. In addition to acting as a deer deterrent because they taste bad, terpenes have antimicrobial and antibacterial qualities that clean the air in the forest, making it pleasant for us to breathe when we decide to indulge in a bit of forest bathing, which is basically like taking a refreshing shower in forest air.

Terpenes are also an essential component of conifer resin. When you see drops of resin oozing down a tree, you know the spruce, fir, or pine is actively defending itself, flushing out intruders such as bark beetles and filling the holes they bore with sticky sap so the beetles cannot crawl inside. I can tell you from experience that if you want to take the weight off your feet or get extra support when crossing a rocky patch in the trail, it’s not a good idea to lean on a sticky conifer as it’s almost impossible to get the resin off your skin and clothes. Out on the trail, you can try rubbing sticky skin on tree bark to remove as much sap as you can. You’ll find some of the dust on the bark sticks to the sap. Now your skin will be dirty, but at least it won’t be sticky any longer. Your clothes, alas, will need to wait for more intense treatment when you get home.

Conifers use terpenes in other ways. On hot days, the trees increase their production of terpenes until they rise in the heat to float above the forest, where they attract water molecules. The gathering water molecules form clouds that shade the forest like an enormous sun umbrella. If there is enough moisture around, the trees might even summon up a raincloud or two. It is terpenes that put the “smoky” in Tennessee’s Great Smoky Mountains as clouds collect over the forested hillsides.

Not all the scents floating around you are defensive. Some are associated with reproduction. Many forest trees are wind pollinated. Alders hang their catkins in the breeze and pines release puffs of pollen from the pinkish-red pollen cones growing at the tips of their branches. The wind provides an efficient distribution service, dusting neighboring trees with male pollen that fertilizes female reproductive organs to start the next generation. You will get dusted, too. If you suffer from allergies, what is a cause for celebration for the pines and Douglas firs will make you reach for a paper tissue or an antihistamine.

Some forest trees, however, need to attract the attention of insects to make reproduction happen. Insects get a light coating of pollen as they crawl into the trees’ flowers in search of pollen and the co-opted carriers then drop off some of the dusty grains at their next floral stop. In forests in the American South, black tupelo trees, magnolias, and black cherries all vie for the pollinators’ attention. In the swamp forests of Georgia and central Florida, bees produce highly prized tupelo honey after visiting the flowers of white tupelo trees.

Flowers are eye-catching, but to get ahead of the game, these trees also make their blooms fragrant to let pollinators know energy-rich food is on offer. Scientists at the University of Tel Aviv have discovered that at least one plant, the evening primrose, increases the concentration of sugar in its nectar when bees buzz by. Perhaps some of the sweet forest aromas you smell are coming from trees keeping an ear open for passing pollinators and stepping up sugar production to lure in customers.

If you are out on a mild, damp fall day, you might become aware of an earthy smell that comes not from the trees but the forest floor. This smell is released as springtails and millipedes, bacteria and fungi break down rotten wood and discarded leaves and process the nutrients they contain, making them available to the next generation of forest dwellers. The earthy aroma intensifies after a rain when the force of raindrops hitting the ground splashes bacterial spores up into the air. The smell is most intense after a dry period when spores have been collecting in the soil. We, as humans, are exquisitely attuned to it. We even have a special name for it: petrichor. Perhaps we find it so attractive because it smells like plenty, the promise of new life about to begin.

When you first stepped into the forest, you might have thought you were the most active organism around, but as you can see, the forest itself constantly reacts to and shapes its environment, from the air above it to the earth below. But now it’s time to get that hike underway.

~ 2 ~ The Root of the Matter

THE FOREST IS full of life, both life you can see and life you can’t. For this reason, unless you are lost and have no choice but to go bushwhacking or are in an area you know well and know it’s okay to do so, on most hikes it’s best to stick to well-established trails. In fact, most national, provincial, and state parks insist that you do.

Sticking to trails is partly for your benefit. Off the trail, you can run into plants that are not friendly to hikers. Poison oaks and sumacs and poison ivies, found across the continent, make nutritious food for many animals, but they can give human hikers an extremely painful itch and rash. In the northeast, the arching roots of hobblebush can trip the unwary. In the forests of the Pacific Northwest, devil’s club, which has particularly nasty thorns, abounds. You can keep yourself safe from all of these if you stay on the trails. Well-worn trails also put some welcome space between you and animals you’d rather not meet, such as snakes—unless they happen to be sunbathing in the open—or come into contact with, such as ticks. If you read on, I will tell you later about my own encounter with these unpleasant little creatures.

Sticking to trails also benefits the forest. Every person who walks around a mud puddle rather than through it increases the width of the trail, which can damage delicate vegetation, lead to erosion, and change drainage patterns in the forest. Creating trails can be a challenging process and popular ones are difficult to maintain if too many people stray from them. So, depending on the time of year, come prepared with footwear that allows you to splash through puddles and mud. (Any children you are traveling with will be more than happy to follow this advice.) If you must walk off the beaten track, you can “make like a herd of elk,” as a hike leader once explained to Jane. That is, a group of hikers spreads out to minimize the impact of their footfalls.

And just one more thing before we head off. In places where invasive species pose a problem, use the boot cleaners at trail heads to brush hitchhiking seeds off your boots. The forest will thank you for your thoughtfulness.

YOU MAY THINK of roots mainly as obstacles to step over as you take your forest hike. When roots intrude onto the trail, you need to spend more time looking at the ground than the scenery around you. Roots become especially treacherous when they are wet or icy. Jane tells me that one day while she was hiking in her local forestlands, her foot landed on a long root hidden under leaves. As slippery as ice, the root stretched downhill away from the path. She almost ended up going down over the edge with it. I had a similar experience in my forest in Germany that I’ll tell you about later. Both of us can attest that it is good to pay attention when there are roots around.

What can be an annoyance for us is, of course, vital for a tree. At the most basic level, roots anchor trees so they stand firm when their tops sway in the wind. Sometimes when the soil gets saturated, roots lose their hold on the ground and high winds blow the trees over. Trees are also prone to tipping over in places where there is not much soil for their roots to penetrate. If you come across a downed tree, you can get some idea of how far its supporting root system extends. For example, by a trail Jane walks on Chuckanut Mountain in Washington State, the root mass of a downed Douglas fir towers above hikers, completely dwarfing them.

Beyond the supporting roots, fine feeder roots feel their way through the upper layers of the forest floor searching for water and nutrients. In Philadelphia, the University of Pennsylvania’s Morris Arboretum hosts a great visual demonstration of this. The distance a tree’s roots travel is painted onto the asphalt path so you can see that even when you are walking way out beyond the spread of the tree’s branches, you are still walking on its delicate root system—yet another reason for you to keep to trails in the forest. Trees don’t appreciate you stepping on their toes.

The weight of one person might not seem like much, but over time repeated footfalls can compress the forest soil, making it difficult for the trees’ roots to breathe. Does it sound odd to you that roots breathe? Like us, roots breathe oxygen and drink water. They can only do this when the soil contains sufficient open spaces to store air and water for the trees’ feeder roots to find. By restricting footfalls to trails, you can minimize damage to the trees’ root systems. Soil compaction, and the resulting loss of spaces for oxygen and water, was just one of the reasons having to use heavy machinery in my job as a forester caused me such distress. Compacted soils are not good for long-term forest health, and once soil has been compacted it takes hundreds, even thousands, of years of hard work by trees and all the tiny creatures working underground to reconstruct the open spaces that have been lost.

In some places in North America, notably the American South, trees such as baldcypress have root systems that spend a lot of time underwater. To get around the problem of submerged roots, baldcypress trees grow “knees.” These specialized roots rise out of the ground around the main trunk. (Yet another hazard to the unwary hiker if these roots are growing right in the trail, which can happen.) Cypress knees can grow up to ten feet (three meters) tall, which is tall enough to extend above the average high-water line, and they are thought not only to stabilize the trees in their watery environment, but also to help the roots breathe by transporting oxygen from the air to the parts that are submerged, acting as a kind of snorkel—although that has yet to be proven.

But roots do more than act as physical support (or even as breathing tubes). You could say the essence of treeness lies in a tree’s roots, for the roots are the first part of the tree to grow and the part that persists most reliably as trees age.

When a tree seed falls to the ground—a poplar seed drifting on the breeze in its coating of fluff, perhaps, or a seed dropped from a pinecone by a squirrel hastily eating its lunch—the first part to start growing is the root, stretching out to find water to fuel the seedling’s growth.

The root is a constant as a tree grows. If the crown of a spruce gets toppled in a winter storm, the tree can grow a new one. Long-lived yew trees grow new trunks after disaster (say, lightning) strikes, which is one reason ancient yews often have multiple trunks. Old Tjikko, a Norway spruce growing in the Swedish province of Dalarna, is estimated to be 9,500 years old and is thought to be the oldest living tree in the world. It has shoots that are younger than this, but the root is its s...

Table of contents

• Cover
• Title Page
• Dedication
• Table of Contents
• Introduction
• 1. Total Immersion
• 2. The Root of the Matter
• 3. What the Trees Can Tell You
• 4. Leaves, Nuts, and Seeds
• 5. The Beauty of Bark
• 6. Hitching a Ride or Paying the Rent?
• 7. The Importance of Decay
• 8. Spotlight on the Decomposers
• 9. Interpreting the Forest for Children
• 10. Forest Activities with Children
• 11. The Forest at Night
• 12. Seasonal Walks
• 13. Hidden Connections
• 14. Spotting Wildlife
• 15. Finding Beauty in Small Things
• 16. A Walk on the Wild Side
• 17. Relying on the Forest to Survive
• 18. Comfort in the Forest
• 19. Striking Out Cross-Country
• 20. Choosing Your Wardrobe
• 21. Getting Creative
• In Closing
• Notes
• Bibliography
• Index
• About the Authors
• Copyright Page