Wood Wide Web – arketyp.

The underground network of microbes that connects trees have been mapped for first time by scientists.

Trees, from the mighty redwoods to slender dogwoods, would be nothing without their microbial sidekicks. Millions of species of fungi and bacteria swap nutrients between soil and the roots of trees, forming a vast, interconnected web of organisms throughout the woods. Now, for the first time, scientists have mapped this “wood wide web” on a global scale, using a database of more than 28,000 tree species living in more than 70 countries.

Before scientists could map the forest’s underground ecosystem, they needed to know something more basic: where trees live. Ecologist Thomas Crowther, now at ETH Zurich in Switzerland, gathered vast amounts of data on this starting in 2012, from government agencies and individual scientists who had identified trees and measured their sizes around the world. In 2015, he mapped trees’ global distribution and reported that Earth has about 3 trillion trees.

Inspired by that paper, Kabir Peay, a biologist at Stanford University in Palo Alto, California, emailed Crowther and suggested doing the same for the web of underground organisms that connects forest trees.

The researchers wrote a computer algorithm to search for correlations between the EM-, AM-, and nitrogen-fixer–associated trees in Crowther’s database and local environmental factors such as temperature, precipitation, soil chemistry, and topography. They then used the correlations found by the algorithm to fill in the global map and predict what kinds of fungi would live in places where they didn’t have data, which included much of Africa and Asia.