Do Plants Talk to One Another? (How do Plants Communicate?)
Not too long ago, a scientist considering the idea of plant
communication would have been ostracized. Research funds were
almost certainly never going to be granted into the investigation of such
a ludicrous idea—and yet today we know for a fact that plants have
extensive networks of mycorrhizal fungi through which they not only
communicate, but exchange vital nutrients.
Peter Wohlleben begins his book, The Secret Life of Trees, with a
fantastic story: he was working on a forest in western Germany when he
found a 400-year-old tree stump. By all logic, that stump should have
been dead; the stump had no green leaves, no way to gather energy for
itself. Yet, Wohlleben concluded, the tree stump was alive. The only
explanation for that was that the stump was getting help from its
neighbors.
It was only later that forest ecologist Suzane Simard changed the game
forever.
Simard had long suspected that plants had a means of communication,
but she needed to objectively prove this somehow. She noticed that
researchers had made trees transfer carbon between each other in a
laboratory, and she wondered whether that would also be the case in the
real world.
Simard then nursed 80 saplings of Douglas fir, paper birch, and western
cedars in a forest. When those plants became sufficiently large, she
borrowed some dangerous equipment from her university—namely, a radioactive isotope of carbon and a Geiger counter. She then put plastic
bags over her trees and injected the radioactive carbon-14 isotope into a
bag containing a paper birch. She also injected the fir bag with a stable
carbon-13 isotope.
One hour later, she came back with the Geiger counter. She tested the
birch’s leaves, which returned a “khhhhhh” noise, indicating radiation.
As expected, the leaves had taken up the radioactive gas. Then she tested
the fir: “khhhhhh.”
The fir was also radioactive—somehow the birch had transferred carbon
to the fir.
Simard also found that the birch tree had taken the stable carbon-13
isotope. “Paper birch and Douglas fir were in a lively two-way
conversation,” she recounted. Notably, she noticed the trees weren’t
communicating with the cedar species.
Today it is known that plants have a symbiotic relationship with
mycorrhizal fungi. The plants allow the fungus to colonize their roots
and even give it sugar, in exchange for help getting water, obtaining
nutrients, and communicating with other plants.
Some trees, for example, can warn their neighbors of impending insect
attacks through these mycorrhizal networks, and the neighbors are
known to put up their defenses in advance of these attacks.
It is theorized that trees evolved this because it is in their individual and
collective interest to keep neighboring trees alive, as this supports their
local microclimate. As Peter Wohlleben said, “Each tree fights for each
other so the whole forest will survive. Every tree is interested in keeping
its neighbors alive because together they create a special climate, which
is cool, humid, where every tree feels comfortable.”
Little is known about these communication systems, and what motivates
trees to help out some neighbors but not others. Much scientific
controversy still exists as to whether this demonstrates some type of
intelligence on the part of trees, and overly enthusiastic scientists are
already comparing mycorrhizal networks to animals’ nervous systems.
Plant communication offers great insight into the interconnectedness of
nature.
Edited by Myles Adoh-Phillips
Written by Lucas L