Scientists estimate global fungal network at 110 quadrillion km

September 22, 2026 at 05:18 AM2 min

This digest was compiled by AI from multiple sources — links to the originals are below.

A team led by the Society for the Protection of Underground Networks published in Science on 11 June 2026 an estimate that arbuscular mycorrhizal fungal hyphae in the top 15 cm of soil total 110 quadrillion kilometres. The figure is based on more than 16,000 soil cores and machine-learning models. Grasslands account for most of the total length.

Key Facts

The total length of arbuscular mycorrhizal fungal hyphae in the top 15 cm of soil is estimated at 110 quadrillion kilometres.
The estimate was published in Science on 11 June 2026 by a team led by the Society for the Protection of Underground Networks.
The figure is based on more than 16,000 soil cores and machine-learning models trained on environmental data.
Around 70 per cent of the world’s plant species rely on arbuscular mycorrhizal fungi.
Laid end to end, the fungal thread would reach the Sun nearly a billion times over.

Measurement Method

The team, led by SPUN’s Dr Justin Stewart with co-lead author Dr Corentin Bisot of the AMOLF physics institute in Amsterdam, combined soil-core measurements with robotic imaging of more than 300,000 living fungal structures grown in the lab. Where field data was thin, environmental variables such as temperature, rainfall, soil chemistry, and plant cover were fed into models that predicted hyphal density. The output is a global density map, released alongside an interactive visualisation built with the data designer Moritz Stefaner. The 110 quadrillion kilometre figure is a modelled estimate, not a direct census.

Scale Comparison

The Sun sits about 150 million kilometres from Earth, and dividing 110 quadrillion by that distance yields roughly 733 million one-way trips to the Sun. The Milky Way is about 100,000 light-years across, which works out to roughly 9.5 × 10¹⁷ kilometres. The fungal thread is a little over 10 per cent of that galactic span.

Grassland Contribution

Grasslands do most of the heavy lifting in the global total.