The Man Who Was Surprised By A Tree

[Below is my--failed--last minute entry into Christianity Today's science essay contest several months ago. Next time, I suppose, I shouldn't wait until the day of the deadline to write. At any rate, enjoy!]

One can be forgiven for thinking there is nothing particularly surprising about trees. As Matthew Battles asks in his book Tree (An Object Lesson), “can something like a tree … be wild” that is, surprising? Unpredictable? 

Such is the constancy of the tree that Rachel Sussman in her beautiful photography collection The Oldest Living Things in the World describes the “stem map” marking the oldest living trees and groves as “reminiscent of a celestial chart; the trees, earthbound constellations.” One is not surprised by a constellation, which regularly lights the way. They do not jump or shout or stalk or pounce; and, as is famous, much to the chagrin of J.R.R. Tolkien, trees do not walk about (Shakespeare’s Macbeth and Scripture’s Mark 8:24 falling a bit short of his childhood expectations for mobile foliage).

Yet, Peter Wohlleben is a man who was nonetheless surprised by a tree. Not by a tiger, or a volcano, or even by a falling tree—which admittedly would be surprising. In fact, to press a bit further, Peter Wohlleben, a forest ranger in Hümmel, Germany, is the man who was surprised by a tree stump. And writing about it in his recent bestseller The Hidden Life of Trees, the rest of us can share in his shock.

“Years ago,” he recalls, “I stumbled across a patch of strange-looking mossy stones in one of the preserves of old beech trees that grows in the forest I manage.” As he surveyed the scene, he realized that he had passed by this odd collection many times without giving them a second thought. The stones, it turned out, were not stones at all, but old wood. Taking a pocket knife to carefully scrape aside some surface bark, to his surprise he found a greenish layer of chlorophyll that could only mean one thing: these pieces of wood were somehow still alive.

“What I had stumbled upon” he explains, “was the gnarled remains of an enormous ancient tree stump. All that was left were vestiges of the outmost edge. The interior had rotted into humus long ago—a clear indication that the tree must have been felled at least four or five hundred years earlier.”

How then were these outermost edges still clinging to life?

Wohlleben immediately ruled out photosynthesis. This stump-shell had no leaves. Nor could it merely be fasting. No creature, certainly not a stump, could starve for this long and live. “It was clear something else was happening with this stump,” he writes. And this “something else” turns out to be quite remarkable: the stump was getting nutrient donations from its neighboring Beeches through their intertwining root systems. It was, we might say, the trees’ century long version of a community project to keep their down-on-his-luck friend afloat through what were obviously less than ideal circumstances.

As odd as it might sound, Beech trees turn out to be quite communal creatures. Even more startling: they seem to care for one another. “To get to this point, the community must remain intact no matter what,” says Wohlleben. For these trees, it isn’t survival of the fittest, but survival of the friendliest. “If every tree were looking out only for itself, then quite a few of them would never reach old age.” Every tree, big and small, strapping or sapling—even an exhausted stump that cannot fend for itself—is worth keeping around. Sick individuals are nourished back to health because “the supporting tree might be the one in need of assistance” the next time around. Wohlleben’s fascinating conclusion is that Beeches, and other species like Oaks, form forests that last for centuries precisely because they act like families.

But is family just a metaphor? Could this interdependence just be an accident? Roots have to go somewhere, after all. It seems merely a matter of probability that they would eventually run into each other in a forest, and this “community” is just the accidental byproduct of an underground meandering. Things are more complicated than this, however. Wohlleben points to recent research showing that trees are perfectly capable of discerning their roots from related trees, and from other species. The hobnobbing roots are thus no accident: there is a type of intentionality here.

“Forests are superorganisms,” he says, “with interconnections much like ant colonies.” They even grow in such a way as to maximize each other’s time in the sun. “These trees are friends,” he says in an interview with The New York Times, pointing to an example of two particularly large Beeches. “You see how the thick branches point away from each other? That is so they don’t block their buddy’s light.”

Wohlleben is unapologetic for this anthropomorphic language, which he liberally applies throughout his book to portray the interaction of trees. This raised the eyebrows of many German biologists when The Hidden Life of Trees was first published. Why use “speak” or “talk” when the more neutral “communicate” will do, they wondered? But it hardly ends there. “Care,” “friends,” “family,” “personality,” “mother,” “child,” “community,” are all just a sampling of the charged words weaving their way into Wohlleben’s descriptions. A hidden life, indeed—these are hardly attributes one typically associates with the woods.

In part, he deliberately uses this language to provoke. We frequently look at trees “as organic robots,” producing oxygen and lumber, he says. This is due in no small part to the influence of the lumber industry, for whom Wohlleben himself also works. He makes it no secret at the outset of his book that the arguments presented “convinced my employer, the community of Hümmel … to [reconsider the] way they manage their forest.”

Additionally, one is reminded of reductive paradigms in the broader world of biology that were long dominant until recently, such as Richard Dawkins’ now infamous description of particular animals and humans being little more than “lumbering robots” designed to carry and perpetuate “selfish” genetic information. While Dawkins will insist this is just a metaphor to aid explanation, other biologists like his friend Denis Noble in The Music of Life stress that metaphors can actually do some heavy conceptual lifting. Metaphors shape what we can see and imagine, what questions we will seek to answer—or not. “Method is metaphor made instrumental,” as George Steiner has elegantly put it. If Wohlleben’s language of community and intentionality seems overcharged at points, it is no doubt because an entirely new way of speaking—and so seeing—trees is on order.

On the other hand, if Wohlleben uses eyebrow-raising descriptors like “talk” regarding trees, this is also in part due to the fact that at some level this appears to be precisely what is happening. Decades ago, scientists noticed that on the African Savannah, Umbrella Thorn Acacias were understandably quite opposed to Giraffes turning them into a mid-day snack. As soon as the foraging started, the Acacias would pump toxins into their leaves to spoil the flavor. “The giraffes got the message” Wohlleben writes, and would move on to other trees. The giraffes did not move to nearby trees, however, but each time proceeded over a hundred feet away to a new grove, and this always upwind. “The reason for this behavior is astonishing,” Wohlleben reports. “The Acacia trees that were being eaten gave off a warning gas (specifically, ethylene) that signaled to neighboring trees of the same species that a crisis was at hand.” Had the giraffes stayed local, or moved downwind, the trees would have already prepared a bitter surprise ruining the herbivores’ salad.

Similar mechanics work among Wohlleben’s Beeches. When caterpillars or other predatory insects begin their buffet, electric signals are pumped through the labyrinthine network of the root systems between trees—lovingly dubbed the “Wood Wide Web” by S.W. Simard and company in a 1997 article published in Nature. Reminiscent of the excruciatingly slow meeting of the Ents in Tolkien’s The Lord of the Rings, these electric signals only travel a third of an inch per minute. Despite this, it is a stunningly precise mechanism. Trees recognize the saliva of different predators, enabling accurate reports from the front line to warn to their fellow trees. In fact, once the saliva has been identified, the Beeches can circle the wagons in defense by releasing pheromones attracting beneficial predators in turn to dine on whatever happens to be eating the trees at the time. All of this leads Wohlleben to claim that there is something startlingly “brain-like” going on.

Trees, it seems are surprising indeed. But scripture itself ascribes a wonderful and startling agency to trees we might have previously overlooked: trees are invited to sing for joy (1 Chron. 16:33; Ps. 96:12) and clap their hands before the LORD (Is. 55:2). In Psalm 148 trees are exhorted to join in with the sun and the moon, the angels, and even the sea monsters to praise God (v.9). The righteous man flourishes like a palm tree (Ps. 92:12) or like a green olive tree in the house of God (Ps. 52:8). In one of scripture’s stranger turns, when besieging a city God commands that trees be spared, “for are the trees of the field a man that they should be besieged by you?” (Dt. 20:19-20). Indeed, if Wohlleben’s research is right, trees often take care of their own far better than we do.

But more than this, Wohlleben’s research gives us a key lesson in how to search for mystery in God’s creation: it is often not just “out there” but right next to us, if we would only look. It is reminiscent of the charming story G.K. Chesterton uses to open his book The Everlasting Man. A boy has set out, bored of his mundane life, to find adventure, to discover “the effigy or grave of some giant,” some wondrous thing.  Having packed his things, and started his long journey downward from the hillock he lived upon, once a good distance away he turned back for one, last look at his homestead, only to discover what he thought was his homely and boring hill, was actually an exotic thing, “shining flat on the hill-side like the colours and quarterings of a shield, [which] were but parts of some gigantic figure, on which he had always lived, but which was too large and too close to be seen.”  Here our giants have not shields but branches, and roots murmuring in the deep dark earth. And when the rains come, perhaps there is a deep rumbling “hallelujah” that spreads like a whisper through the soil.