Wood Wide Web
Contrary to what you might expect, in a forest most trees and shrubs are interconnected with a web of fungi via their root system. It is like the Internet of the woods, where the mycelium assists in the transport of nutrients and valuable information, also known as: 'The wood wide web'.
In forest-a-like ecosystems nitrogen is the essential building block plants thrive upon. The more nitrogen available the more growth or fruits a plant, shrub or tree can bear. The air is full of nitrogen, but trees can't get access to it themselves. Instead, via their root system they live in symbioses with a specific type of bacteria – Frankia – known as a nitrogen-fixing bacteria. The Frankia bacteria converts nitrate nitrogen, from air pockets in the soil, to ammonium nitrogen that is usable by the tree. Almost every tree has this relationship in some form, but some excel at it and produce more nitrogen than they can use. These trees are commonly known as: 'nitrogen-fixing trees'.
Nitrogen-fixing trees have built a second beneficial relationship, which is where the mycelium comes in. The beneficial fungi can transport the surplus of nitrogen to nearby plants in exchange for sugars. Most plants use photosynthesis in their green parts to produce those carbohydrates. For the mycelium it is a good trade, because fungi are unable to produce it themselves. The great thing is that the transportation abilities of mycelium aren't limited to just nitrogen. More and more research shows that all sorts of important minerals and chemicals can be distributed by the fungi.
Besides the transportation of nutrients, mycelium plays another vital role in the forest ecosystem. Imagine a large herd that arrives at the edge of a forest, browsing the wealth of edible greens. Shrubs or trees are unable to move or find shelter when they are in danger. Instead, some produce a bitter or even toxic substance to avoid that an animal eats all their leaves or even rip off its bark. They also warn nearby trees and shrubs by releasing specific chemicals that are transported by the mycelium to trees and shrubs close by. These plants start producing the bitter or toxic substance in advance, before the animal arrives.
In the video below, Professor Suzanne Simard explains how this process of exchange works. As if this doesn't blow your mind yet, she also coins the idea of 'mother trees' supporting young trees. This concept nuances the core of Darwin’s idea in which every living organism acts as an individual competing for survival of the fittest. Simard states that they actually help each other out to survive.
Other mycelium uses
Mycologist Paul Stamets is crazy about mycelium, as you will probably find out when you watch the two videos below.
6 ways mushrooms can save the world
Our mycelium wizard Paul Stamets continues his statement on mycelium in his TED talk where he states that mycelium fungus can help save the universe by: cleaning polluted soil, making insecticides, treating smallpox and even flu viruses.