Suzanne Simard sealed paper birch and Douglas fir seedlings inside plastic bags, fed them carbon-14 and carbon-13 dioxide, and nine days later found carbon had crossed between species through fungal threads in the British Columbia soil beneath her boots (opens in new tab)

Suzanne Simard’s 1997 forest experiment did not show trees whispering to each other. It showed something narrower, stranger, and easier to test: carbon that began in the air around a paper birch seedling later appeared inside a neighbouring Douglas fir, after passing through roots and fungal tissue in the soil. The experiment, published in Nature […]