THERE ARE A LOT OF HUMANS. Teeming is perhaps an unkind word, but when 8 billion people cram themselves on to a planet that, three centuries before, held less than a tenth of that number, it seems apt. Eight billion hot-breathed individuals, downloading apps and piling into buses and shoving their plasticky waste into bins – it is a stupefying and occasionally sickening thought.
And yet, humans are not Earth’s chief occupants. Trees are. There are 3tn of them, with a collective biomass thousands of times that of humanity. But although they are the preponderant beings on Earth – outnumbering us by nearly 400 to one – they’re easy to miss. Show someone a photograph of a forest with a doe peeking out from behind a maple and ask what they see. “A deer,” they’ll exclaim, as if the green matter occupying most of the frame were mere scenery. “Plant blindness” is the name for this. It describes the many who can distinguish hybrid dog breeds yet cannot identify an apple tree.
Admittedly, trees do not draw our attention. Apart from plopping the occasional fruit upon the head of a pondering physicist, they achieve little that is of narrative interest. They are “ sessile” – the botanist’s term meaning incapable of locomotion. Books about trees often have a sessile quality, too; they are informative yet aimless affairs, heavy on serenity, light on plot.
Or, at least, they were until recently. The German forester Peter Wohlleben’s surprise bestseller, The Hidden Life of Trees (published in English in 2016), has inaugurated a new tree discourse, which sees them not as inert objects but intelligent subjects. Trees have thoughts and desires, Wohlleben writes, and they converse via fungi that connect their roots “like fibre-optic internet cables”. The same idea pervades The Overstory, Richard Powers’ celebrated 2018 novel, in which a forest scientist upends her field by demonstrating that fungal connections “link trees into gigantic, smart communities”.
Both books share an unlikely source. In 1997, a young Canadian forest ecologist named Suzanne Simard (the model for Powers’ character) published with five co-authors a study in Nature describing resources passing between trees, apparently via fungi. Trees don’t just supply sugars to each other, Simard has further argued; they can also transmit distress signals, and they shunt resources to neighbours in need. “We used to believe that trees competed with each other,” explains a football coach on the US hit television show Ted Lasso. But thanks to “Suzanne Simard’s fieldwork”, he continues, “we now realise that the forest is a socialist community”.
The idea of trees as
