Food for Thought: The Wood Wide Web

Plants can talk, and that matters for food production.

“Talking trees. What do trees have to talk about, hmm… except the consistency of squirrel droppings?” - Gimli, The Lord of the Rings: The Two Towers

If you’ve had the pleasure of walking deep into a forest and sitting amongst the trees, you might’ve experienced the feeling of being surrounded by life, the feeling of being a small part of a larger whole. The birdsong and insect sounds blend with the wind and the rustling of leaves and for a moment it can feel like, more than the sum of its parts, the forest itself is alive. 

As it turns out, this might be more than just a feeling.

The Wood Wide Web

We don’t look at plants the same way we look at animals. Most people would agree animals have some kind of intelligence. They communicate, they make decisions, and many of them have their own forms of social networks and hierarchies. 

We also know plants are alive, but oftentimes they don’t exactly display life in the ways that we recognise it. Most people certainly wouldn’t consider plants to be intelligent. But, it turns out plants are in fact communicating with each other all the time, making decisions (you can get into semantics here and argue it’s not decision making as they’re not consciously deciding so much as reacting to stimuli in some programmed way, but that shouldn’t get in the way of a good story), and operating within a kind of social network.

This is all facilitated through something known as the Wood Wide Web. 

If you’ve been reading these posts for a while you’ll know I’m fascinated by fungi, so you won’t be surprised to hear that the Wood Wide Web is of course a product of the amazing abilities of fungi and the way that they form symbiotic relationships with plants. 

At a high level, the Wood Wide Web is fairly simple - fungi need energy to thrive, and plants need nutrients. Plants can create energy through photosynthesis in the form of energy-rich sugars, and fungi can excrete enzymes that break down soil nutrients into water-soluble forms. There’s clear opportunity for a trade here, and plants and fungi have been taking advantage of it for 450 million years. 

By forming links in the root system, plants provide sugars to fungi and in exchange the fungi provide nutrients to the plants. 

It’s a nice trade and a neat little symbiotic trick, but this is where it starts to get really interesting. Fungal networks are extensive - they can cover far larger surface areas than the roots of a plant and so in most cases the hyphae (the branching arms of mycelium) are in contact with not one, but many plants. This creates a network.

Researchers have found, only fairly recently relative to other big discoveries, that plants can use these networks to communicate with each other. Using chemical and electrical signals plants and trees can use fungal networks to communicate all sorts of things, like “there’s disease here” or “prepare for pests” or even signal to new sprouts to say “this way is up”. 

Even more amazing, trees have been shown to use these networks to share resources. A larger adult tree for example can send carbon to its offspring when they’re too small to get enough sunlight to photosynthesise themselves. In a sense, plants and trees are caring for their neighbours (whether they do it for their own good or for the good of others is unclear - there are competing views of these networks as “capitalist” or “socialist” networks).

What this means for food

Besides just being a fun fact, this knowledge has important implications for agriculture and gardening. Having healthy soil and in-tact fungal networks can allow your plants to communicate with each other. If one plant gets attacked it can warn others and give them time to produce pest-repelling toxins, or they can share resources if a nearby plant is in less-than-ideal conditions. 

The best way to keep these networks in good health is to minimise soil disturbance (not tilling or turning your beds), keeping the soil covered, keeping living roots in the ground for as much of the year as possible, and feeding your soil with lots of compost and organic matter.

Having healthy soil means your plants can operate as a network and ultimately be more resilient to pests and disease, and potentially even achieve better yields. So next time you think “I can probably skip watering my plants today” just remember, they might be talking about you…