Wood Wide Web
This is another great one from www.radiolab.org…
Everyone knows how trees grow – right?
Sunlight + CO2 + Photosynthesis = Carbon (in the form of sugars) + O2
We’ll it turns out that this is only half the story. A tree made only of carbon wouldn’t grow more than a foot high before flopping over like a dying tulip.
The structural elements that build trunk and limbs come in as nutrients through a tree’s root system – just like we eat vitamins and minerals to build healthy teeth and bones.
Now I’ve seen tree roots and it’s always struck me as strange that what are essentially underground branches are able to suck up all that goodness.
Well it turns out that they can’t – not in any meaningful quantity at any rate.
Instead trees rely on a hidden and hitherto unknown network of fungal tubes to do the sucking for them.
These magical mushrooms are many times thinner than a human eyelash and so have gone unnoticed, but there are about 7 miles of them in every pinch of soil!
Here’s what happens :
- The shrooms wrap around a root and request access to the tree’s circulatory system
- The tree obliges by softening the walls of its cells and an exchange begins
- The tubes weave through the soil until they encounter a useful obstacle
- Pebbles are attacked with an acid which dissolves the calcification and unlocks the minerals they contain. The tubes literally bore their way through rock, leaving internal trails and caverns
- Insects which live underground and eat the fallen leaves are pierced by the fungal fingers and KEPT ALIVE while nitrogen is slowly milked from their bodies
- Discarded fish (from bears apparently) are digested and their fabulous fatty-acids dragged remorselessly into the hellish tubEs which give 20% of what they collect to the trees in exchange for (wait for it…) up to 80% of the sugars that the trees produce.
If the story stopped there then it would already be amazing, but the best is yet to come, because the mushrooms are not local to a single tree – rather they connect every tree to its neighbors, creating a giant networked organism “indistinguishable in structure from an animal brain”.
This Wood Wide Web is truly remarkable. Here are the highlights :
- The www acts as a carbon bank for trees. During good times a tree can deposit sugars in the network, confident that it can withdraw again when times are hard
- When a tree dies, it dumps all its resources into the www which redistributes it – not to neighbors, or to trees of the same species, but to trees most likely to survive the hardship (WTF?)
- When a tree is attacked (e.g by an insect), it sends warning signals to all the other trees via the www. The trees react by producing toxins that deter the attacker
So the next time you walk through a wood, just think of the countless miles of tubes beneath your feet, feeding those magnificent bastards that tower above you, shooting messages from tree to tree just like the neurons in your brain, and ask yourself if vegetarianism isn’t the cruelest irony of all…