Mycorrhizal Fungi
Mycorrhizal fungi are the internet that plants forgot to mention they need.
Mycorrhizal fungi are the internet that plants forgot to mention they need. These microscopic threads colonize over 90% of plant species' roots, trading soil nutrients for plant sugars in a partnership so fundamental that most terrestrial ecosystems would collapse without it. The fungi didn't just co-evolve with plants - they enabled plant life on land 400 million years ago. Without mycorrhizae, there are no forests.
You can't see them, but they're everywhere. A single teaspoon of forest soil contains kilometers of fungal hyphae - threads 2-10 micrometers wide that extend far beyond where roots can reach, mining phosphorus and nitrogen from rock and dead matter. Plants pay handsomely for this service: up to 20% of everything they photosynthesize goes to feeding their fungal partners. But plants aren't passive clients - they discriminate, routing more sugar to fungi that deliver better nutrients, maintaining quality control through resource allocation.
This is infrastructure: invisible, foundational, expensive to maintain, catastrophic when it fails. Disrupt mycorrhizal networks through tillage, fungicides, or soil compaction and plant diversity crashes within years - not because you killed plants, but because you destroyed the distribution system they depend on. The business parallel is precise: your most critical infrastructure isn't the thing customers see. It's the layer below that makes everything else possible. Lose it and you discover it wasn't 1% of the system - it was 100% of the foundation.
Notable Traits of Mycorrhizal Fungi
- Symbiotic nutrient exchange with plants
- Enables 90%+ of plant species
- Invisible keystone holding plant communities together
- Extends plant nutrient access
- Receives up to 20% of plant photosynthesis
- Bidirectional chemical signaling
- Evolved ~400 million years ago
- Associates with >90% of plant species
- Single mycelium can span square kilometers
- Billions of hyphae per individual
- Cannot photosynthesize - depends on plant carbon
- Provides nitrogen, phosphorus, water to plants
- Transmits chemical warning signals between plants
- Symbiotic with >90% of plants
- Enhances phosphorus uptake
- Extends root absorption area
Mycorrhizal Fungi Appears in 4 Chapters
Over 90% of plant species depend on mycorrhizal partnerships. Representing less than 1% of forest biomass, they enable the majority of plant diversity. When disrupted, plant diversity crashes and forest regeneration fails.
Keystone Infrastructure →Mycorrhizal fungi form partnerships with over 90% of vascular plants, exchanging nutrients for carbohydrates. Plants discriminate among fungal partners, allocating more resources to better providers - maintaining balanced exchange through responsive communication.
Managed Mutualism →Microscopic fungi creating the 'Wood Wide Web' that connects forest ecosystems. Evolved ~400 million years ago, enabling terrestrial plant life. A single mycelium can span square kilometers; one teaspoon of soil contains kilometers of fungal threads.
The Wood Wide Web →Form symbiotic relationships with plant roots, dramatically increasing nutrient absorption surface area. Critical for nutrient cycling, especially phosphorus acquisition in nutrient-poor soils.
Nutrient Distribution Networks →