People generally think of trees as disconnected loners, competing for water, nutrients, and sunlight, with winners shading out losers and sucking them dry. But evidence to the contrary is coming to light. Forest trees are, in fact, cooperative and live in interdependent relationships maintained by communication and collective intelligence similar to an insect colony.
Unlike other organisms, most of the communication between trees happens underground, through a system known as the “Wood Wide Web”. “[Trees] in every forest that is not too damaged”, explains Peter Wohlleben, a German forester and author, “are connected to each other through underground fungal networks. Trees share water and nutrients through the networks, and also use them to communicate. They send distress signals about drought and disease, for example, or insect attacks, and other trees alter their behaviour when they receive these messages.”
As a fee for their services, the fungi consume about 30 percent of the sugar that the trees photosynthesize from sunlight. This sugar fuels the fungi as they scavenge the soil for nitrogen, phosphorus and other mineral nutrients, which they then pass on to the trees. For young saplings in dense parts of the forest, the network is a lifeline. Without sufficient sunlight to photosynthesize, saplings can only survive because big trees, including their parents, pump sugar into their roots through the network.
