The internet of trees: how trees talk to each other underground
In June, ecologist Suzanne Simard gave a talk at TED about her 30 years of research into how trees talk to each other. Underneath the forest floor, there is a communications network on which trees — even those from different species — trade carbon with each other, send warnings, and trade messages. Simard described one of her first experiments (from the transcript):
I pulled on my white paper suit, I put on my respirator, and then I put the plastic bags over my trees. I got my giant syringes, and I injected the bags with my tracer isotope carbon dioxide gases, first the birch. I injected carbon-14, the radioactive gas, into the bag of birch. And then for fir, I injected the stable isotope carbon-13 carbon dioxide gas. I used two isotopes, because I was wondering whether there was two-way communication going on between these species.
The idea was to use the isotopes to track whether the trees were trading carbon when some of them were shaded and less able to make their own energy.
The evidence was clear. The C-13 and C-14 was showing me that paper birch and Douglas fir were in a lively two-way conversation. It turns out at that time of the year, in the summer, that birch was sending more carbon to fir than fir was sending back to birch, especially when the fir was shaded. And then in later experiments, we found the opposite, that fir was sending more carbon to birch than birch was sending to fir, and this was because the fir was still growing while the birch was leafless. So it turns out the two species were interdependent, like yin and yang.
Fascinating. German forester Peter Wohlleben came out with a book this week called The Hidden Life of Trees: What They Feel, How They Communicate (Simard contributed a note to the book). From a Guardian review:
Trees have friends, feel loneliness, scream with pain and communicate underground via the “woodwide web”. Some act as parents and good neighbours. Others do more than just throw shade — they’re brutal bullies to rival species. The young ones take risks with their drinking and leaf-dropping then remember the hard lessons from their mistakes. It’s a hard-knock life.
The Monthly, Maclean’s, and Scribd all have excerpts of Wohlleben’s book if you’re interested.
Update: See also this episode of Radiolab, From Tree to Shining Tree. (via @Chan_ing)
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