Peter Wohlleben’s book has become bestseller in Germany but he tells Hay festival audience it has annoyed scientists

Trees are social creatures that mother their young, talk to each other, experience pain, remember things and have sex with each other, a bestselling author has said.

If that persuades you to go and hug the nearest tree, then great, said Peter Wohlleben. Just avoid a birch: “It is not very sociable. Try a beech.”

Wohlleben was at the Hay literary festival in Wales to talk about a book, The Hidden Life of Trees, which has become a bestseller in his native Germany and, remarkably, prompted an online petition against it from scientists.

A former state forester, Wohlleben believes the world has been misled about how humans should treat trees, but he told Hay his anthropomorphising of them had aggravated the forestry industry.

Two scientists from the University of Göttingen started the online petition, calling for “facts not fairytales”, he said. The petition states: “It is very unfortunate … that, through this book, so many people obtain a very unrealistic understanding of forest ecosystems because the statements made here are a conglomerate of half-truths, biased judgments, and wishful thinking derived from very selective and unrepresentative sources of information.”

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Wohlleben said he deliberately anthropomorphised trees but everything he wrote was based on science.

“At university we were told that cutting down trees was good for the environment,” he told Hay. “That we are renewing forests. I believed it … it took time to get that brainwash out of my head.”

The wisdom has been to cut down a big tree so the younger trees have more space to grow, he said, but apply that to human society and … “it would be OK to kill the parents? The children will have more space in the house afterwards?”

He criticised the supposedly green policy of power stations replacing the burning of coal with wooden pellets. “We destroy trees to prevent climate change?”

Wohlleben wants society to be more aware of trees’ “feelings”. Trees that are close to street lights, which burn all night, will die earlier, he said.

Pollarding trees – removing the upper branches to promote a dense head of foliage – is also a bad thing. “It is like cutting your fingers, it hurts and it damages the tree very heavily. A wound more than 3cm deep can cause a fungal infection and perhaps 10 or 20 years later the tree will rot.”

He said people pruning trees were often not particularly educated about what they were doing, and that they were in effect killing trees.

He pointed to a study of African acacia trees, which shows how they release a chemical when giraffes start eating them, as evidence of how trees communicate. The chemical released drifts through the air warning other trees of the danger and they in turn begin producing toxic chemicals before the giraffe has reached them.

Wohlleben acknowledged that he used simple expressions to explain himself. When he talked about oak trees using 600 words, he was talking about a chemical language.

Above all most trees want to live socially, said Wohlleben. “Trees don’t want to grow fast. They want to have companions. They want to live in social groups … they support each other.”

Some trees might have sex every three to five years and go the toilet once a year. “They have stuff they need to get rid of so they pump their waste into their leaves. When you are walking through a forest in winter time you are walking through tree toilet paper.”

Wohlleben was a state forester but now looks after a forest on behalf of the community in Hümmel, Germany, where machinery is banned and the trees are left alone.

Wohlleben is adamant that his book is based on facts, and he is merely popularising the truth. “That’s what I want to do. The scientific community have had 40 years to explain to people and no one knows it … that’s not their fault; they have to express it like that.”

For all his love of trees and appreciation for their feelings, Wohlleben said he was not suggesting we should stop sitting on wooden seats – although we should be aware they are “tree bones” – or not put wood on the fire – “the burning corpse … It is OK to use it. I’m not against using wood otherwise I wouldn’t sell any books. But we should think about what we are doing at least.”

The Hay festival audience was rapt and his book sold out within minutes at the site’s bookshop.

All of those good people were buying slaughtered trees but should not feel guilty. “My aim is that everyone loves trees and when you love trees you do the right thing,” he said.