Three guests: Suzanne Simard, a professor of forest ecology and teacher at the University of British Columbia, Jennifer Frazer, a science writer that has a blog called The Artful Amoeba, and Roy Halling, a mycologist.
The connection between trees
- Normally trees from different species are competitors.
- Suzanne noticed that by cutting a birch tree, the fir tree next to it dies.
- She leads an experiment to test it out.
- She sealed trees into plastics bags and injected radioactive gas.
- The trees sucked up the gas.
- Where does isotopes go after?
- They are shared between trees.
- 1 tree was connected to 47 other trees.
- The bigger and older the tree is, the more connected it is.
- Trees have a complex communication network.
Wood Wide Web
- The communication is not only made by the main roots.
- The feeder roots that communicate too.
- There are little white threads attached to the roots, smaller than an eyelash.
- They’re everywhere and some even go on for 7 miles.
- Not really plants, but a fungus.
- They’re hollow, like tubes.
- A fungi freeway.
Why are fungi creating this network and why do trees need it?
- The tree has something the fungus needs and the fungus has something the tree needs.
- A tree turns inorganic carbon into organic carbon.
- CO2 into sugar.
- If they only had that mechanism, trees wouldn’t be tall.
- They need minerals
- For example, nitrogen is used in DNA and in lignin cells, which make the tree rigid.
- Fungus can draw water and nutrients from the soil.
- Trees can only absorb nutrients from the tip of its roots.
- That’s not enough.
- Fungus takes sugar from the trees to build their bodies.
- They communicate through chemical signals.
- Fungus tells the tree to soften their roots so they can enter.
How is the fungus getting the minerals?
- It hunts, fishes and strangles.
- They developed a system for mining.
- They worm their way back and forth until they reach a rock.
- They secrete acid and dissolve the rock.
- They suck up the minerals.
- They can also hunt.
- There are some insects living in the soil, called springtails.
- Fungi eat them.
- They have a way of telling if the insect is dead or alive.
- They pierce them and suck the nutrients out of them.
- They can even absorb the nutrients from carcasses of animals that seeped into the soil.
- In some trees, 75% of their nitrogen comes from fish.
How much sugar do the trees give to the fungus?
- The estimate, which depends on each ecosystem, is from 20% to 80%.
- Trees that don’t need sugar right now give it to the fungi.
- When they need it, the fungi can give some back.
- It’s like a bank system.
Alerting the forest
- Trees can also send danger signals through the network to other trees.
- So the other trees start producing chemical that tastes bad to prevent insect from eating them.
- If a tree is dying, he’ll send his carbon to his neighbours.
- Maybe it’s the fungi that decides who gets what.
- Food ends up with new trees that are better at adapting.
- This is the intelligence of the forest.
- Forests act like one big organism.