The underground world of trees

Recent scientific findings about trees are turning forestry on its head, according to Suzanne Simard, who studied forests for over 30 years.

“Instead of (replanting) rows of trees, its families of trees,” said Simard, professor of Forest Ecology at the University of B.C., who was featured in the documentary “The Intelligence of Trees.”

There was standing room only at the San Juan Public Library on Saturday evening, Jan. 27, when the “Intelligence of Trees” was shown. The event was sponsored by the San Juan Chapter of the Washington Native Plant Society and Griffin Bay Books. The Washington Native Plant Society was formed in 1976, with a mission to promote, educate and appreciate native plants. Jane Wentworth, the chairwoman of the society, introduced the film.

“Intelligence of Trees” follows Simard, German forester Peter Wohlleben, who wrote the book “Hidden Life of Trees,” and Teresa Ryan Smhayetsk, postdoctoral fellow of the Forest and Conservation Sciences at the University of B.C.

Contrary to previous notions of forestry, Wohlleben says in the documentary, trees do not need space or to be separated, but like to grow together as if to “cuddle.” Instead of obstructing light and space, he says, they carefully try not to block each other and keep their limbs away from each other. Their roots, on the other hand, become entwined, and through their roots, support each other. Trees are able to pass nutrients, water, carbon dioxide, as well as messages of warning, even fear.

Early on, Simard had a hunch there was a lot more to the forest floor and root systems than was previously known, and suspected trees might transfer nutrients, water, and carbon dioxide to each other underground.

She and her students tested these theories in experiments using plastic mesh bags, radioactive isotopes and liquid nitrogen.

Her discoveries were that not only do trees help their neighbors, but through a network of fungus strands, trees support each other across the entire forest, and support trees of different species as well.

Smhayetsk was not surprised to find forests may work almost as one organism.

“We have a saying,” she said. “Everything is one.”

Smhayetsk has been studying not just trees, but how rivers and salmon affect the forest as well. Bears and other wildlife bring salmon from the river up into the forests to eat, and it is thought that the remains of those feast help fertilize the surrounding forest floor.

If trees are able to transfer nutrients to one another, are they able to transfer messages like danger?

Simard was able to prove they do send messages of pain, measuring the electrical impulses of neighboring trees, as she cut a small branch from one seedling, freezing that branch in liquid nitrogen to measure the impulses occurring in it.

Again, she found trees are able to communicate via their networks of roots and fungus.

Researchers were then able to map the roots and found that some trees, what is commonly referred to as mother trees, or the biggest, oldest trees, are major hubs of information and support sources for the forest.

“It’s almost like the internet,” she explained, or, Simard continued, like a human brain, with roots acting as neurons.

If these mother trees, or if too many of these mother trees are killed, it affects the entire forest.

“When you cut down trees, you not only destroy the connections but the families,” Wohlleben said, adding that the “kids” are left to defend themselves. Old-growth trees can be as old as thousands of years, while young trees can be up to hundreds of years old. In Germany, Wohlleben added, only a fraction of old growth forests are left.

Simard also noted that mother trees invest a great deal of energy into seedlings when the environment is habitable, but if it is inhabitable, like if there is a drought or pest infestation, she does not support them as much.

Humans have always relied on trees. They have been used for shade, heat, food, shelter, furniture, art, and paper products. It is no surprise people feel close to them, and many are not surprised to hear there are more to them than meets the eye.

“When I mention these findings to people, they say, ‘Oh yeah,’” Simard said toward the end of the film.

After the film, there was a discussion about the pending Friday Harbor Airport clearcut.

Eleven acres south of the Friday Harbor Airport runway, including wetland areas and walking trails, will be clearcut and replaced with a different species of tree this winter. The mature, mostly Douglas Firs are considered an obstruction by the Federal Aviation Administration and need to either be topped or cut. After studying the forest, port staff decided topping the trees was not a good option because it would create an unsafe forest by creating dead snags and unhealthy trees.

“There really isn’t hope to protest this,” said longtime islander Shann Weston. “The FAA is making the port do it. But, anyone interested in helping replant afterward, please contact me.”

For more information, read Wohllemben’s “The Hidden Life of Trees,” or listen to Simards Tedx talk at www.ted.com/talks/suzanne_simard_how_trees_talk_to_each_other#t-1086966. To learn more about the Native Plant Society, visit www.wnps.org/sji/home.thml.