The Secret Social Life of Trees

A hidden underground. network allows trees to move nutrients and chemicals around. The question is why.

- Rachel Kehoe

Trees may appear to be solitary beings. But they are more connected than it seems. Just beneath our feet lurks a complex underground network of fungi. Trees use this system to pass information, share food, and even wage war on their competitors. Ever-clever scientists have nicknamed this network the "wood wide web."

Underground Network

Every tree has underground roots that keep it anchored in the soil. Most of these roots are covered in a fuzzy, thread-like fungus that grow in and around tree roots. Together, the roots and fungi are called mycorrhizal. This mycorrhizal network spreads like a web, often connecting the roots of many neighboring trees and plants.

Trees and fungi rely on each other. The fungi provide trees with water and nutrients from the soil. In return, the fungi receive sugars from the tree. This relationship is called mutualistic-both organisms benefit. Trees with mycorrhizal fungi are healthier than those without. 

Mycorrhizal fungi also boost a tree's immune system and help forests thrive. Some scientists estimate that 90 percent of all plants have mycorrhizal fungi.

The Secret Language of Trees

For some time, mycorrhizae were believed to be simply an exchange of nutrients between fungus and plant. But in recent decades, scientists have discovered a deeper level of interaction. Mycorrhizae connect individual trees and let them transfer water, carbon, and other minerals.

Suzanne Simard was one of the first scientists to study fungal networks. She is a professor of forest ecology at the University of British Columbia in Canada. In one study, she shaded young saplings that were surrounded by older trees.