The Hidden Infrastructure Beneath Our Feet: A Global Map of Mycorrhizal Networks

Mycorrhizal Infrastructure Map

The Hidden Infrastructure Beneath Our Feet: A Global Map of Mycorrhizal Networks

SPUN has released an interactive map revealing the vast, hidden network of mycorrhizal fungi that connects plants worldwide. The map visualizes hyphal density of arbuscular mycorrhizal fungi, showing where these underground networks are densest, from grasslands to croplands. It highlights the surprising scale of this biomass and its critical role in ecosystems, offering a new perspective on global biodiversity and soil health.

Hyphal density of AM fungi (m/cm³)
  1. culi

    > To answer this, we used a combination of approaches. First, we conducted a global meta-analysis of studies in which researchers measured the length of fungal hyphae in local soils using microscopes. This length of hyphae per unit of soil is known as “hyphal density”, and it provides a way to quantify how much fungal network is present in a given amount of soil. We assembled data from 322 studies, representing more than 16,000 individual soil cores collected across 9 global biomes. This gave us one of the most comprehensive datasets of arbuscular mycorrhizal fungal hyphal density compiled to date, spanning ecosystems from forests and grasslands, to drylands and farms.

    > We then used these observations to train a machine learning model. The model was built using dozens of geospatial environmental layers, including climate, vegetation, soils, and land use. By learning how measured hyphal density varied across these environmental conditions, the model allowed us to predict the density of AM fungal networks across Earth’s terrestrial ecosystems at a fine spatial resolution of approximately 1 km². We also used spatial uncertainty analyses, including bootstrapping, to understand where predictions were more or less certain.

    This is absolutely mindblowing work! One of the best things I've ever seen on the internet. I only wish it was granular enough to help identify mother trees[0] in individual forests

    [0] https://www.scientificamerican.com/article/mother-trees-are-...

  2. albumen

    Very cool. "The resulting map is strongest in well-sampled regions, less certain where samples are sparse. Read more about mapping uncertainty here." I can't access the paper to see what countries were actually sampled. The interactive map implies/shows that large areas weren't sampled (e.g. nowhere in the British Isles). It would be helpful if the map showed the uncertainty of the resulting map, on the map somehow.

  3. MathMonkeyMan

    Proud to see that my home state of Florida is absolutely lit up with root fungus.

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2026-08-18