Hardcover,
288 pages
Published in 2016
by Greystone Books, Canada
Peter Wohlleben is a German forester. In times of need, often family members, friends, colleagues and neighbours would offer to help you. Likewise, you wouldn’t hesitate to help them. If there is a greater need, you may choose to convey a concerning message even to neighbouring communities. This network of people offers a great support system that allows you to confide problems within a safe environment. We, humans, work cumulatively in such ways,showing love and care, but also because we depend on each other as a communal species. Given this, is it hard to imagine that other living organisms, such as trees take such decisions and measures for their own good and survival. A tree is not a forest, yet forest consists of many different trees.
Friendship
Even fungi and mosses are a part of it. Is it true that they all work collectively to protect the forest? In the “Hidden Life of Trees”, Peter Wohlleben writes mesmerising facts about the trees that most of us never knew about. In a collection of 36 short chapters, he explains the friendship between the trees, their communication, and relationship to other entities in the forest. He also raises the notion that trees are not merely for commercial use in our modern world and reflects on how astonishing and intricate their mechanisms of communications are.
Knowing that they need each other for protection, trees take great measures to create networks throughout the forest to ensure their survival.The roots from one tree can recognise the roots from the trees of the same kind. They then interconnect with each other and make root networks. Such networks share food and water, thus caring for each other. Didn’t you wonder how an old tree stump with no leaves can stay alive for a long time? The author demonstrated that these roots share and contribute nutrients even with the competitive trees for the survival of the forest.
The book explains the ability of a tree to produce its own chemicals for survival. For example, in African forests, when the giraffes start to eat the leaves of the “umbrella thorn acacia” trees, the trees counteract the stress as a result of the giraffes by releasing toxins into their leaves. This action deters the giraffes, chasing them away. These trees also emit a gas (ethylene) as a warning signal to nearby trees about the threat. This way, neighbouring trees can prepare by sending toxins to the leaves before the giraffes reach them. The cumulative effort by the trees discourage feeding behaviour by the giraffes who often move to a different area altogether.
Since communication by gas emission depends on the climate and the wind, trees also use their root network as an alternative method for sending messages. Communication through roots is done by sending both chemicals and electrical impulses with a speed of about 0.33 inches per minutes. In this fast paced world, it may seem insignificant; however, for a tree growing naturally for a really long time, this is a considerable speed.
But, as in our society, where selfish people exist, likewise, there can be such tree members whose root systems may not participate in communicating vital signals to the neighbouring trees. In such cases, fungi in the soil jumps to action to fill the void. In case of an insect invasion, lack of water, or other challenges, Wohlleben explains that these fungi can act as underground “fiber-optic internet cables”. These root systems and fungi networks are referred to as “wood wide web” by the scientists.
Enemy attack
In an enemy attack, depending on the need, trees are capable of creating different chemicals. Trees can use an insect’s saliva to identify the kind of insect. Wohlleben shows how accurate their identification is by demonstrating with a caterpillar. During a certain caterpillar attack on an elm or pine, the trees had emitted a pheromone that attracted a particular species of wasp that ate the caterpillars.
The ability of the trees to counteract pests and make such decisions is really amazing. However, trees are not the only members of the forest who have such skills. According to the book, insects too are capable of identifying weak trees that they can attack. Trees lose the ability to produce the chemicals when it is compromised. Therefore, insects instigate an initial attack and wait for the tree’s response. If the tree doesn’t react and produce the chemicals to deter the insects, the insects learn that the tree is weak or sick.
Strategies
The strategies that the trees take to propagate their species is mesmerising, as described by Wohlleben. As an example, some deciduous trees cumulatively predict and decide their propagating tactics in advance. Their seeds that fall onto the ground in the summer stay on the forest floor during the winter waiting for the spring to germinate. Since the seeds of beech and oak trees are the staple food of the deer and wild boars, these trees have adapted to know that none of their seeds will remain by spring, on the forest floor.
So, the trees have adjusted to produce flowers, and hence seeds, only in random years to ward off feeding by animals. In the year that no seeds are produced, many pregnant animals die due to starvation reducing their current population.
Trees then produce seeds in the following season, knowing that they would be capable of saving some seeds on the ground to follow through to the next spring.
It doesn’t matter whether a tree grows in a boreal forest or in a tropical rain forest, a tree is a tree. When we were children, we went out of our way to kick a Nidikumba plant only for innocent fun without thinking how the plant would respond to the touching. However, our elders took certain actions on plants/trees with certain expectations. They made fires under some trees or hung coconut shells in lime trees if the trees weren’t fertile. How did they know that such actions would provoke the trees to react to this type of stimuli and make decisions to bloom? Unlike most of us in the modern world, elders loved and respected the trees. They must have known the extraordinary abilities of the trees to sense these actions and the surrounding environment.
The way I perceive and look at a tree has totally changed after reading this book. Trees can live happily without us, but most of us forget the fact that we can’t live without trees. Although, only a small portion of the book was summarised in this article, I would be so glad if this information is enough to even slightly change your attitude towards a tree. We, for no reason, often unintentionally pluck some leaves or flowers when walking past a tree or a bush, carry them for a bit and throw them away. It is time for us to think twice about such acts and respect the intricacy and elegance of the tree community as if it was our own.
- Dr. Dammika Manage