Network of ‘mother trees’ keeps forests healthy, says UBC researcher
WILLIAMS LAKE TRIBUNE — A UBC researcher says there’s a more sustainable way to harvest trees that would mean faster forest regrowth and more skilled jobs for British Columbians.
CAPTION: The mother tree experiment involves monitoring regrowth after selective harvesting in B.C. forests. (Submitted photo)
Forest ecology prof. Suzanne Simard is following the progress of 8 forests in B.C., including the John Prince Research Forest in Fort St. James, that were selectively harvested to leave behind the bigger, older trees that she says play a vital role in regrowth.
Simard began the mother tree experiment in 2015 looking at ways to preserve B.C. forests as the climate changes. She said that as opposed to clear-cutting, leaving behind the “mother trees” comes with both environmental and economic benefits.
“The big old trees help protect biodiversity, keep carbon in the ground and help regenerate the next forest. The forest was harvested in that way about four years ago,” Simard said.
The John Prince Research Forest is at the northern limit of the interior Douglas Fir in Canada and is the most northern forest being studied. Simard said northern forests are especially vulnerable to harsh climate when it comes to regrowth.
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Trees might not look like they’re connected but Simard said they do “communicate” with each other below ground through a network of root systems and fungi that transmits and exchanges nutrients between them. The “mother trees” are important hubs for those networks.
“The little seedlings that come up around these old trees hook into that network supported by the old trees,” Simard said. “The old trees send nutrients, water and carbon directly into these little seedlings and help them get going.”
She said there is a 20 to 30 per cent increase in seedling survival when the bigger trees are left standing. The older trees also keep the ground moist and protect seedlings from drying up in the summer.
“These old trees are really important in regenerating the next forest. When you leave old trees, the biodiversity of the ecosystem is also protected,” Simard said. “They also help reduce wildfire in these ecosystems because they have thick bark that can resist the fire.”
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Simard said she came by her interest in forestry naturally as her grandfather and great-grandfather were horse-loggers in the Kootenays.
Having grown up around the industry Simard believes selective logging creates long-term employment and better yields out of the forest over time — while also keeping carbon dioxide, which contributes to global warming, out of the atmosphere.
“These are really good solutions where we can still harvest trees, but it becomes more of a careful approach,” Simard said.
“It protects ecosystem values and ultimately also provides more jobs, because they’re skilled jobs. It takes a lot more skill and labour to selectively log forests than sending in a machine to clear-cut. You create a whole new economy.”
Simard has published more than 200 scientific and popular science articles. Her book, “Finding the Mother Tree”, was published in 2021 by Knopf at Penguin Random House. She will be in Prince George on April 7 to introduce the idea of the mother tree network.
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