The Hidden Life of Trees: What They Feel, How They Communicate-Discoveries from a Secret World

So, let's get back to why the roots are the most important part of a tree. Conceivably, this is where the tree equivalent of a brain is located. Brain? you ask. Isn't that a bit farfetched? Possibly, but now we know that trees can learn. This means they must store experiences somewhere, and therefore, there must be some kind of a storage mechanism inside the organism. Just where it is, no one knows, but the roots are the part of the tree best suited to the task.

Early in The Hidden Life of Trees, author Peter Wohlleben makes the point that when it's asked how trees pump water from their roots to their uppermost branches, we all have some vague answer involving capillary action, transpiration, and osmosis; as though this is settled science; I know that's what I learned in elementary school. And indeed, scientists have always found trees to be so unmysterious that they haven't actually investigated how even their most basic systems work, and presently, no one can quite explain just how trees do pump water all the way to their upper reaches. Noting the void in scientific research, Wohlleben – a German forester whose career took him from managing an artificial lumber forest to his current role as the caretaker of an “environmentally friendly woodland” – has written a book that attempts to fill in the blanks with his own observations (valid and useful) and his own leaps of logic (credibility straining). Throughout, his tone is that of an enthusiastic amateur nature lover, not an academic, and with frequent anthropomorphism and a parenthetical Ouch! every time he mentions a tree being pruned or attacked by beetles or fungus, I couldn't quite grant Wohlleben the authority necessary to bring me around to his more colourful points-of-view. Yet, full points for that enthusiasm. 

At least as far as water is concerned, there is research in the field that reveals more than just behavioral changes: when trees are really thirsty, they begin to scream. If you're out in the forest, you won't be able to hear them, because this all takes place at ultrasonic levels...Vibrations occur in the trunk when the flow of water from the roots to the leaves is interrupted. This is a purely mechanical event and probably means nothing. And yet?

Wohlleben does pepper his musings with some of the latest research, and what he shares is really quite interesting. His main proof for “the hidden life of trees” involves the newly discovered “wood wide web” of underground fungi that connects the root systems of the various trees in a forest, apparently relaying information through electrical signals. Because of this interconnection, trees are able to coordinate mass events (like the irregular fruiting “mast years” of oaks and beeches), and if an individual tree is doing poorly, nearby individuals will share resources through their roots. Because large trees seem to be able to recognise their own offspring and prefer to share with and shelter their own, Wohlleben makes the leap to referring to these as mothers and babies, using terms like nursery and kindergarten, and extrapolating from these “relationships” notions of consciousness and emotions. And that's a leap too far for me.

When you know that trees experience pain and have memories and that tree parents live together with their children, then you can no longer just chop them down and disrupt their lives with large machines. 

And yet, trees don't need to be somehow sentient for everyone to recognise that they are vital to the health of the planet, and it's becoming more and more clear that there is more of biological value going on in an old growth forest than in the straight rows of a transplanted commercial woodlot. Wohlleben describes current efforts in Germany to allow five per cent of their forests to return to a wild state, but the process sounds challenging in human terms: where there are currently cultivated Douglas firs, it will take a couple of decades for them to die off without human intervention, and while the lumber companies lament that they should have been able to harvest the trees while they were still healthy, visitors to these woods will see stands of dead trunks. Within a couple more decades, these dead firs will fall over and have hopefully seeded the next generation, and with any luck, some native beeches and oaks will begin to grow in their shade (which is the best start for these trees to enjoy long lives). In about another century, the next generation of firs will be dead and the native trees will race to fill the canopy, finally in a position to start reproducing themselves. If left entirely alone to attract the varieties of bacteria, fungus, beneficial wildlife and tree seeds that are present in a healthy forest, this process will take about five hundred years. I just can't see people not meddling in all that time, and especially if the forest will look dead for entire human lifespans. (And as a meddler, I don't see why the lumber companies can't clear out those valuable Douglas firs if they're just going to be in the way of the native species for the first two hundred years of the rewilding process; why can't it be helped along with the transplanting of healthy young beeches and oaks?)

I, for one, welcome breaking down the moral barriers between animals and plants. When the capabilities of vegetative beings become known, and their emotional lives and needs are recognized, then the way we treat plants will gradually change, as well.

The Hidden Life of Trees is a very light read, and I had to wonder if something was lost in translation from the German; it simply didn't feel very polished or professional (the Afterword by Dr. Suzanne Simard of UBC was a sudden and stunning contrast with its smooth and polished prose; if only the whole book read like that). And no, I couldn't follow Wohlleben on his more fanciful leaps, but I was charmed by him nonetheless.