TThe first global map of the network of roots, bacteria and fungi underground, known on the "wooden wide net", was built by researchers amid fears that it is under threat of climate change.
An international study published in the journal Nature has made a visual model of "Mycorrhizal fungal nets" based on data from 1.2 million plots in more than 70 countries.
It is believed that discoveries can help shed light on how this invisible world is important for limiting climate change and how network damage can accelerate the rise in temperature.
Researchers at Stanford University in the United States and Crowther Laboratory at ETH Zurich, Switzerland, have joined a huge database of the Global Forest Initiative to shape the work.
Professor Thomas Crowater, one of the authors of the report, told the BBC: "This is the first time we have ever understood the world under our feet but globally.
"Just as MRI brain scan helps us understand how the brain works, this global map of the fungus under the soil helps us understand how global ecosystems work.
"What we find is that certain types of microorganisms live in certain parts of the world and understand that we can understand how to recover different types of ecosystems and how the climate is changing."