Into the woods

In the past 10 years the idea that trees communicate with and look after each other-dubbed the 'wood-wide web' - has gained widespread currency. But have these claims outstripped the evidence?

- Daniel Immerwahr

THERE ARE A LOT OF HUMANS. Teeming is perhaps an unkind word, but when 8 billion people cram themselves onto 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".