Dr. Suzanne Simard, scientific researcher into how trees communicate with one another.

Trees are communicating with one another, says Suzanne Simard, Professor of Forest and Conservation Sciences at the University of British Columbia, and what they're sharing is vital information about how to keep the whole forest healthy.

Spreading among the roots of trees and connecting them, Simard has discovered a complex underground web of delicate, threadlike fungi. Moving carbon, water, and nutrients among the trees, this network connects young trees and old ones, healthy trees and those under stress. Simard also found that the trees are not just randomly passing these substances to one another, but directing them specifically toward the plants that most need them. "Plants are not individuals," she explains. "They are a community helping one another to survive."