The Hidden Life of Trees

The Hidden Life of Trees describes how trees can communicate, support each other, learn from experience, and form alliances with other inhabitants of the forest.

For an amateur who only visits the forest every once in a while, trees may seem mindless. Most people assume that whatever is encoded in their genetics simply conditions the entirety of the trees’ lives.

Wohlleben has been observing individual trees doing for years. If you did the same, you would inevitably notice that each and every one of them is unique. This is because trees are able to “remember” experiences and learn from them – which, over time, forms their unique “personalities.”

Any tree needs to make a multitude of decisions over the course of its lifetime. These include important resolves, such as how long to keep the leaves on, or in which direction to grow roots. If a tree makes a mistake, like shedding leaves after the first frost, it won’t make the same one again.

How differently individual trees interpret their experiences is illustrated by an example of the three oaks that grow very close together on Wohlleben’s land. Observing them over the years, the author has realized that one of them always sheds leaves two weeks earlier than the others.

Since all of them experience exactly the same weather conditions, the explanation needs to be something else. That oak tree has grown to simply be more “careful” than its companions.

Although it may seem like it, trees aren’t loners. Actually, just the opposite is true – most of them evolved to be committed, team players. They each care a whole lot about their fellows in the forest. Not being able to move and run away, trees developed alternative systems of protecting themselves against various threats. Most of these systems are founded on communication and mutual support within the forest community. One example is the communication network trees develop by connecting their roots through a system of underground fungi. Thanks to certain fungi species, that grow over areas of many miles, trees can “stay connected” by transmitting electrical impulses through that root-fungi network. This is useful, for example, to warn other trees about an invasion of pests or upcoming drought. There are also other warning mechanisms – for example, based on scent. In African savannas, umbrella acacias’ leaves often get eaten by giraffes. When that happens, the tree starts producing a toxic substance that stops the herbivores from munching on their branches within minutes. Simultaneously, that same substance produces a “warning scent” that other acacias around immediately pick up on – and so, they can prepare for the giraffes’ attack in advance. Another form of support trees give to one another is…