A team led by ecologist Justine Karst of the University of Alberta reviewed 1,676 studies published over the past 25 years about the structure and functions of these studies. mycorrhizale networks It turns out that three of the premises on these “exchanges” of information or nutrients, or “partnerships” between trees and fungi, are based on a very small number of studies, always the same.
Thus, one way to prove the existence of these networks would be through comparative analyzes of the genes of fungi and plants living around the roots of several trees of different species and from different locations. But according to this review of the scientific literature, this was only done with two of the world’s 73,300 tree species. the study Posted on February 13 in nature.
Another hypothesis is the “warning signals” that neighboring trees send to each other through this network: here again, a peer-reviewed study points only in this direction, yet it was made in a greenhouse.
“There is some evidence, and we think it is possible that these trees are connected,” Nuance lead author on new world. “But we don’t have very good control over that,” and even if these networks exist, we won’t know how long they can last.
In English, the premise benefited from a more catchy name: “The Wide Wood Web”. The researchers, led by Susan Simard, a forest biologist at the University of British Columbia, and colleagues at the University of Oregon, are oft-cited their posts Pioneer, featured in nature on August 7, 1997 — and I got on the cover that week.
The premise is attractive -” Trees talk to each other ‘, according to the established expression – and Suzanne Simard has continued to defend it ever since, developing the concept of ‘ mother tree —the central tree, which would act as a kind of hub for this “network”. This last concept was, according to some, the inspiration for James Cameron’s film symbol picture.
But despite the attractiveness of the hypothesis, it is possible that we may encounter what the scientific community calls ” Citation bias “: This expression refers to the tendency—particularly in health—to cite more often studies that suggest a significant effect, or the tendency to cite prior studies that agree with our conclusion preferably. In other words, in this case, the researchers who wanted In defense of the hypothesis they find themselves citing the same small group of studies more often than not.
This does not mean that the hypothesis is wrong. However, this means that we jumped to conclusions too quickly and that there is still work to be done to prove that this network exists, that it is capable of communicating information or sharing nutrients.