The first day in the forest of British Columbian, when she started her research, Suzanne Simard, a mother grizzly bear and her cub chased her off the job. But she persevered and eventually completed her research. She put on her respirator, and then put plastic bags over her trees to isolate them above ground. With her giant syringes she injected the bags with her tracer isotope carbon dioxide gases. First, she did that to the birch. She injected carbon-14, the radioactive gas, into the bag of birch. And then for fir, she injected the stable isotope carbon-13 carbon dioxide gas. She used two isotopes, because she wanted to know if there was two-way “communication” going on between these species of trees. She wanted to identify the source of the isotopes. She waited an hour because she estimated that this would be enough time for the trees to suck up the CO2 through photosynthesis, turn it into sugars, send it down into their roots. In fact, she hypothesized that the trees would transport the carbon belowground to their neighbors.
When the hour was up, she moved her Geiger counter over the leaves and heard the perfect sound—Kkhh—that indicated to here that in fact the birch had taken up the radioactive gas. Then she moved to the fir tree to see what she would hear there. She heard what to her was a beautiful sound, namely, the same Kkhh! She interpreted this as the sound of the birch tree “talking” to the fir tree. In fact, she interpreted that to mean that the birch was in effect asking the fir tree if it could help it out and the birch “replied” that in fact it could help. Specifically, Simard theorized that the fir was asking for carbon because Simard had placed a shade cloth over it.
This of course is where the sceptic could ask what the justification was for making these conjectures? Was there a better or simpler explanation for the movement of carbon? Was her conclusion a leap of faith instead of an inevitable scientific conclusion based on the available data? I am not so sure, though I find her conjectures deeply intriguing.
After that she examined the cedar and speculated it was silent. The Cedar was in fact in its own world and was not connected to the “Web interlinking birch and fir.” Was there such a web, or was this wishful thinking?
Simard thought the data was clear and irrefutable. In each of her 80 plots she checked all the replicates. The C-13 and C-14 was showing that “paper birch and Douglas fir were in a lively two-way conversation.”
She claimed that the data showed that at that time of the summer, the birch was sending more carbon to the fir tree than the fir tree was sending back to birch and that this was particularly evident when the fir was shaded. At other times of the summer, she discovered that fir was sending more carbon to birch than birch was sending to fir. She speculated that this was as result of the fact that the fir tree was still growing while the birch was leafless. According to Simard, “The two species were interdependent, like yin and yang.”
That led Simard to an epiphany—a Eureka moment. She believed she had made a major discovery that would change forever how scientists look at trees in a forest and how they interact in it. Trees are “not just competitors but…cooperators.” If that is true, that is a revolution in science. She believes that she found solid scientific data that proved there is “a massive belowground communications network, the other world.”
Simard hopes that with new understanding of forests there will come a new way for humans to interact with forest. She really hopes that instead of clear-cutting and instead of applying herbicides we will employ what she called more holistic and sustainable methods. These methods will also be more practical and less costly.
She explained how she viewed her science in relation to these issues. She used science to determine how paper birch and Douglas fir were communicating? According to her research, they were conversing not only in the language of carbon but also nitrogen and phosphorus and water and defense signals and allele chemicals and hormones. All of this she refers to as “information”.
Hard to believe, but…
Maybe forests are more interesting than we ever thought. In fact, maybe nature is ever more interesting than we thought it was.
