The Wood Wide Web

  • By Anna Rothschild
  • Posted 02.02.17
  • NOVA

Plants use an Internet made of fungus. Explore this powerful network in this episode of Gross Science.

Running Time: 04:08


The Wood Wide Web

Posted: February 2, 2017

Imagine you're walking through a forest. Everything might seem quiet...but beneath your feet is a flurry of conversation. All the plants around you are actually talking to each other. The trees and the shrubs and the flowers are passing information back and forth, with serious life and death consequences. So, how are they communicating? They’re using a giant network of fungi—one so pervasive and powerful that some scientists have started comparing it to the Internet. They’re calling it the “Wood Wide Web.”

I’m Anna, and this is Gross Science.

The so-called Wood Wide Web is made up of what are called “mycorrhizal fungi.” There are many different types of mycorrhizal fungi, but generally these little guys will grow on the roots of plants and provide them with water and nutrients—like nitrogen and phosphorus—in exchange for sugars. While they’re incredibly thin, the threads of the fungi can be up to 1000 times the length of a tree root. This allows the fungi to connect together many different plants. Once connections are made, the fungi can act almost like the neurons in our brain, transporting signals from plant to plant. And these networks are everywhere. It’s estimated that around 90% of land plants are connected to some kind of mycorrhizal network.

So, how can plants use these networks? Well, to begin with, they can help each other out in times of stress. For example, during the fall months, when paper birch trees lose their leaves and can’t produce sugar, Douglas-fir trees may shuttle them nutrients through the fungal network. And in the summer, when paper birch trees have lots of leaves, they send sugars to young Douglas-fir saplings growing in their shadows.

Plants can also warn each other of danger. Douglas-fir trees connected by a fungal network can alert their ponderosa pine neighbors if they’re attacked by budworms. In response, the neighboring ponderosa pine trees will produce insect-repelling chemicals—even though they haven’t been directly exposed to the insects themselves.

Mycorrhizal fungi can also enable parental care of among plants. Some adult trees will help out their younger relatives by sending those seedlings more nutrients through the fungal network than they send to strangers. The adults may even make more room for them in the soil by reducing the number of their own roots.

But not everyone is so generous. Much like our internet, things can sometimes get a little nasty on the Wood Wide Web.

Take Black Walnut trees, for example. They can spread poison through the network, hindering the growth of their neighbors. And the fungi making up the network can be just as tricky. Mycorrhizal fungi tend to pick favorites. They may share resources with one species of tree, but bleed another species dry without giving anything back in return. The fungi may also judge a plant's health. If they think it’s too weak or sick, they may not allow it to receive nutrients or danger signals from the network.

Now, we’re only beginning to understand how complex these relationships get. But imagine the possibilities for agriculture and forestry. If we find out certain species share well across the network, maybe we can plant them near each other to yield better harvests, or grow healthier forests.

So next time you’re walking through the woods or the park don’t forget to thank the fungal web beneath your feet.




Host, Producer, Editor, Animator
Anna Rothschild
Writer, Researcher
Eliza Lehner
Camera, Sound
Rachel Aviles
Special thanks to Dr. Suzanne Simard.


Original Footage
©WGBH Educational Foundation 2017
Forest waterfall
POV Looking up through the trees
In forest
Blueberry Bush
fern, forest flower
Time-lapse of growing fly agaric mushroom, RGB + ALPHA matte (720p)


Jelly Mangling On Plate
Jelly Wobbling On Plate 1
Ice Styrofoam Crackling Foley
Machine Sucking and Expelling Air
Basket Creak
SFX Gross Guts Slime Goo
Tape Pulling Off Surface
Poof of Smoke
Produced by WGBH for PBS Digital Studios


Time-lapse of growing fly agaric mushroom, RGB + ALPHA matte (720p)


Want more info?

Pathways for below-ground carbon transfer between paper birch and Douglas-fir seedlings:

Defoliation of interior Douglas-fir elicits carbon transfer and stress signalling to ponderosa pine neighbors through ectomycorrhizal networks:

Suzanne Simard’s TED Talk:

Related Links