Take a walk into the forest and close your eyes. Do you hear something? Anything? Wind rustling through the fallen leaves, maybe a bird overhead, a deer trotting nearby, but do you hear the trees? They’re talking to one another: communicating their needs with their mother, sharing resources with a sibling and perhaps sending a warning out to a distant cousin. It’s all happening right before your ears and eyes my friend, right below your feet! The trees are talking!
This communication system has been around longer than we could even imagine. Paintings, stories and other folklore regarding talking trees date back to ancient times. If you think back to most of the stories from your childhood, I would bet there is some reference to talking trees or even trees in general. Alexander the Great was said to have visited a talking tree that told him how he would die. Willow trees played a large part in English folklore and in Ireland the trees were said to help one find a leprechaun’s gold (although usually to no avail). Forests themselves provide a certain aesthetic of wander and enchantment, making a great setting for a nursery rhyme or folktale. The Japanese have always had a deep appreciation for nature, including trees in particular, and often wrote of them with great detail and appreciation in their poetry and stories. Even before official scientific research confirmed it, the Japanese believed that inside each tree was a spirit, or kodama, and that the trees (or spirits within them) would communicate with one another.
A great communication system exists right below our feet that is even more widely used than the World Wide Web and perhaps even more important. It is sometimes referred to as the wood wide web. A network of thousands, if not millions of root systems connected via fungi, that transmits resources and information to different trees throughout the forest thriving beneath our feet. This is called a mycorrhizal network.
Each tree has its own root system that works to transfer minerals and moisture to the tree. Within the root system of a tree, two types of roots exist: woody and non-woody. The woody roots provide overall structural support for the tree as well as the transportation of minerals and water and the storage of carbohydrates. The non-woody roots are found closer to the ground’s surface. These non-woody roots absorb the minerals and moisture and are also where one might find mycorrhizal fungi. These are a special fungi found on the smaller, non-woody roots and whose body resembles tiny threads. These threads reach out even beyond the root system of the tree and stretch out across the forest floor. These threads are called mycelium. Mycelium “infects” other trees’ root systems, connecting one tree to another, creating a network of connected trees. This is the mycorrhizal network and it can span thousands of acres and connect entire forests.
Because of this connection to one another, roots can share resources such as carbon, nitrogen and phosphorus. This network is very similar to a computer network as it consists of hubs, or mother trees, and nodes, which are younger trees. Mother trees will share nutrients with the younger trees to help them grow. Ecologist Suzanne Simard discovered the interworking of this system of the Wood Wide Web two decades ago and through field experiments, was able to prove that the trees are indeed sharing information in the form of different nutrients and that when trees were not a part of a mycorrhizal network they tended to not do as well as those that were.
Mycorrhizal fungi trade their host tree minerals for glucose as well as connect them to other trees, thus assisting them even further in their growing process. Hyphae, or tiny thread like fibers, extend from the mycelium and “dig” holes into surrounding rocks which release extra nutrients that help the tree grow. If you’ve ever been digging around in the dirt in or a near a forest, you may have noticed the dirt being stuck together by a web like system of roots. This is the hyphae and it usually exists throughout the forest floor. In fact, just a pinch of dirt can contain over thirty thousand feet of hyphae!
Along with allowing trees to share resources that help them to flourish, the mycorrhizal network also provides the connected trees with a defense system. Through this wood wide web, trees within the network are able to warn each other of pending danger. For example, a tree that is bitten by an insect can release a chemical signal out to other trees in its network enabling them to prepare themselves by releasing a bitter tasting compound that make the leaves taste less appealing to the insects. This is pretty amazing!
Did you know that trees can be social? Well, they don't meet at coffee shops for a chat but what happens to one tree in a network can affect those that are around it. For instance, if a tree within a network dies, others around it may suffer. If a few trees in a network die, this may cause the surviving trees to experience hardship and those trees may also die if they are not able to establish a connection with other healthy trees. Trees that are close to one another can be quite friendly and will even grow branches away from each other, allowing all of their “friends” to thrive.
Complicated. Simple. Amazing whichever way you see it. I suppose there was more truth to James Cameron’s 2009 film, Avatar. Those who have seen the movie may remember that on planet Panodra the roots of the trees are all interconnected. The trees communicate with one another and the people of planet Pandora, known as Na’vi, are able to communicate with the trees as well. The trees on Pandora are vitally important to the Na’vi people. They provide them with homes, a means of communication and a religious connection to the Eywa (the Na’vi people’s deity). The Na’vi people worship the trees and treat them with the utmost respect because they understand that these trees are vital for their survival. The people on planet Pandora can even communicate with the trees by plugging in their tails.
Here on planet earth, most of us humans do not have tails that would work well plugged into a tree, but perhaps we can still learn from the people of Pandora. Maybe we can learn to treat our trees with more respect and be grateful for the bounteous fruits that they supply us with such as oxygen, food, shelter and medicine. We must also learn to reduce our consumption in order to preserve our natural forests. And perhaps as a society, we can even take notes from the wood wide web and learn to work better together to help each other and our beautiful planet thrive.
-Alesia Gallo, Environmental Educator