Finding the Mother Tree: Uncovering the Wisdom and Intelligence of the Forest

by Suzanne Simard

In my first experiment testing whether birch transmitted carbon to fir through mycorrhizas, I thought I’d be lucky to see anything, but then I detected a pulse strong enough to fuel the setting of seeds. I saw fir giving back to birch the energy it needed to build new leaves in the spring. And my posse of students confirmed the findings of reciprocity, not just between birch and fir but among all sorts of trees. In making the mycorrhizal-network map, I thought we might see a few links. Instead we found a tapestry. With Yuan Yuan, I figured it would be a long shot if dying Douglas firs transmitted messages to ponderosa pines. But they did. Another of my students confirmed it in a second study, as did others in labs around the world. Then I considered it a gamble that Douglas-fir Mother Trees would recognize their own kin, never mind that the signals might move through the mycorrhizal network—and mon Dieu! The firs recognized their relatives! The Mother Trees not only sent carbon to help support their mycorrhizal fungal symbionts, they somehow enhanced the health of their kin. And not only their kin, but of strangers too, and other species, promoting the diversity of the community. Was this all luck?