If you are new to learning about this, you may be surprised that trees share carbon, and even favor their own children. Now before you call me crazy and leave, this is backed by science, I promise.

This starts with Suzanne Simard, a Canadian ecologist. In her research, she bagged the above-ground portions of several wild trees to isolate them, then injected some of them with tracer isotope carbon dioxide gases. If she later used her Gieger counter and found that a plant she never injected had a reading, that would mean that the plants were sharing through fungi networks.

It turns out they were sharing, and not just sharing, but doing it selectively. For example, during times when the fir trees were still growing but the birch were leafless, the fir would send more carbon to the birch compared to other times in the year.

"I found that most was in the birch and fir. Just by looking at the data, I could determine there was communication going on between them." Suzanne Simard in the article Secrets of a tree whisperer: ‘They get along, they listen – they’re attuned’

And it was not just mutually beneficial competition, either, there was also favoritism. It turns out the mother trees recognize their own young, and not only do they spread out underground to reduce root competition for their kids, but they also send their kids more carbon than other seedlings of the same species. This increases the chance of survival of her kids.

On top of all that, if a mother tree is dying, she will send out a mixture of carbon and defense signals. Those defense signals act as instructions on how to deal with stresses and can make the seedlings stronger.

So how do the trees do all that? With fungi! When we think fungi, we tend to think mushrooms, but the mushroom is just a small part of the fungi. Most of the fungi are underground and look like tiny thread-like roots, and is called Mycelium.

That mycelium weaves through the soil, and infects the roots of trees and plants. In turn, trees use this network to their benefit by sending carbon to their roots, through the mycelium, and to the roots of another tree. This is nicknamed the Wood Wide Web.

So, the next time you are walking through a forest, know that below your feet, there is a complex network of communication happening between trees.

If you want to learn more about this, Suzanne Simard has a YouTube video here, and a book titled Finding the Mother Tree. For a quick video explanation with more information, here are some videos:

At the moment I'm delving into Robert Macfarlane's latest book Underland and it's such an inspiring read. Macfarlane makes us look at the world below our feet - caves, mines, roots, catacombs - and realize that the way we see the world is literally only surface-deep. This drawing is a bit of a meditation on the subject of what lies below our feet, and how the earth links everything together; even life and death (where it becomes clear that one cannot do without the other).