Over the holiday period I read The Hidden Life of Trees: What They Feel, How They Communicate―Discoveries from a Secret World. The author, Peter Wohlleben, a forester from Germany, has become an unlikely media star and his book has become a bestseller, and not just among tree-huggers.
Mr Wohllben draws on recent research to argue that trees not only communicate with each other, they also feel pain and help each other out. He writes,
“Beeches, spruce, and oaks all register pain as soon as some creature starts nibbling on them. When a caterpiller takes a hearty bite out of a leaf, the tissue around the site of the damage changes. In addition, the leaf signal sends out electric signals, just as human tissue does when it is hurt.”
When a giraffe starts eating an African acacia tree, the tree releases a chemical into the air that prompts neighbouring trees to pump a toxic chemical into their leaves to make them unpalatable for the giraffes. When attacked by pests, some trees release a chemical that attracts predators that feed on the pest that is attacking the tree.
In a forest the trees communicate with each other through a “wood-wide-web” of soil fungi through which they can also send sugars that can help sustain sick relatives. One such fungus, in Switzerland, covers almost 120 acres of forest and is an estimated at about one thousand years old.
“Another in Oregon is estimated to be 2,400 years old, extends for 2,000 acres, and weighs 660 tons. That makes fungi the largest known living organisms in the world.”
In a note at the end of the book, forest scientist Dr Suzanne Simard describes how douglas firs can live in synergy with neighbouring birch trees,
“We discovered that the exchange between the two species was dynamic: each took different turns as “mother”, depending on the season…mother trees recognize and talk with their kin, shaping future generations…These discoveries have transformed our understanding of trees from competitive crusaders of the self to members of a connected, related, communicating system.”
But what about agricultural crops, plants grown for food or fibres? Peter Wohlleben writes,
“Thanks to selective breeding, our cultivated plants have, for the most part, lost their ability to communicate above or below ground. Isolated by their silence, they are easy prey for insect pests. That is one reason why modern agriculture uses so many pesticides. Perhaps farmers can learn from the forests and breed a little more wilderness back into their grain and potatoes so that they’ll be more talkative in the future.”
And in the preface to the English edition, Tim Flannery writes,
“Perhaps the saddest plants of all are those we have enslaved in our agricultural systems…They have lost their ability to communicate and are isolated by their silence.”
All this creates something of a problem. Anyone who watched the wonderful BBC series Blue Planet II last year will know that fish and (particularly) octopus are way more intelligent than we had thought—and way more social. We all knew that that sea mammals were social, but it was a shock to think that other sea animals, including shellfish, can have emotions and feel pain.
Consumers and legislators are already reacting. For example, the Swiss government recently banned boiling live lobsters, arguing that they really do feel pain. Lobsters now have to be “humanely” killed before being cooked.
I know some previously fishing-eating vegetarians who have now given up eating fish—or at least feel guilty when they eat it—after watching Blue Planet II. I am afraid to recommend that they now read The Hidden Life of Trees.