The first global map of the network of roots, bacteria and fungi beneath the ground known of the “wood wide web” has been built by researchers amid fears it is under threat by climate change.

An international study, published in the journal Nature, made a visual model of "mycorrhizal fungi networks" based on data from 1.2 million forest tree plots in more than 70 countries.

It is believed the findings could help shed light on how this unseen world is important to limiting climate change and how damage to the network could accelerate temperature rises.

Researchers from Stanford University in the US and the Crowther Lab at ETH Zurich, Switzerland, tapped into a vast database by the Global Forest Initiative to shape the work.

Prof Thomas Crowther, one of the authors of the report, told the BBC: "It's the first time that we've been able to understand the world beneath our feet, but at a global scale.

"Just like an MRI scan of the brain helps us to understand how the brain works, this global map of the fungi beneath the soil helps us to understand how global ecosystems work.

"What we find is that certain types of microorganisms live in certain parts of the world, and by understanding that we can figure out how to restore different types of ecosystems and also how the climate is changing."