It Takes a Forest to Raise a Tree

By Elmer Joy

February 23, 2018

We think of trees as individuals. That’s how they are sold in nurseries, with the root ball bound in burlap, planting instructions attached. Dig a hole twice the size of the root ball, insert the tree, tamp fresh soil around the root ball, mix in a generous sprinkling of gentle fertilizer or bone meal, and fill the hole with water. Allow to soak in. Fill the hole with available soil. Tamp the soil and water again. The curiosity is that this freshly planted specimen will neither grow as tall nor live as long as the same species of trees seeded naturally in a forest without the benefit of pampering or even breaking the soil. Why?

What foresters will tell you is that trees are not so much individuals as members of a community. Peter Wohlleben, a professional forester in Germany, has written a delightful book entitled “The Hidden Life of Trees.” In it he highlights ways in which trees relate to each other, and illustrates how they and their partners, mostly in the soil, support, feed, and otherwise nurture each other. Especially in old forests.

Take, for example, the umbrella thorn acacia in the African Savannah, whose leaves are the preferred diet of the towering giraffe. Within minutes of the first nibble, the tree starts to pump ethylene gas into the leaves so as to prevent them all from being devoured. The giraffe moves on, not to the next tree, but to a tree at least a 100 yards away.

The gas is not only toxic to the feeding giraffe, but a signal to neighbouring trees to emit the same gas so as to prevent the giraffe from nibbling on them too. It seems, then, that trees communicate for the benefit of their friends.

How is it that other trees, such as the spruce or oak “know” that they are being nibbled on, say by a caterpillar? Can it feel pain or discomfort? We have no way of recording such pain, but it is known that once bitten an electrical signal is slowly sent throughout the tree inviting defensive compounds that ward off the pest. Other trees emit pheromones summoning the exact friendly predators needed to deal with a specific pest.

Secrets of the forest underground expose a complex of roots that, once again, illustrate the community nature of forests, especially those that are old. Roots do not simply grow around each other in some tangled jumble, but often grow into each other, so that roots of a weaker tree can be nurtured or given water by another that is healthier or growing in better soil. Even stumps of long cut trees have been shown to have life in them because they remain connected to this network of roots.

Forest in Summer-by Intern Emily Upcott04

Of course the forest is more than its trees. In fact, some 60% of the forest is underground. Unsung heroes such as a host of insects, bacteria, nematodes and friendly fungi provide a range of support mechanisms. Fungi, particularly, join in with the complex root system to create what has been jokingly called the “wood wide web”.

This short teaser is not intended so much to draw you to the closest bookstore, but to invite us all to stay awhile in the closest forest. It’s a particularly healthful exercise, with Korean studies on visitors to forests showing improvements in blood pressure, lung capacity and even the elasticity of the arteries. No wonder “forest bathing” has become a popular exercise in Japan.

Even more, this short look into the hidden life of trees draws us into the presence of the Creator who makes all things good. Our anthropomorphic predispositions are relativized when one sees something of God in the grandeur of the astonishing forest, even in the not-so-mundane insects and fungi.

Stay updated with our newsletter

Our global family has also been at work in conserving forests. Check out A Rocha International’s African Forest Programme and see how forests in Kenya and Ghana can be protected to flourish biodiversity and people that depend on them.