The Wood Wide Web debate
Where the evidence for tree-to-tree sharing is weaker than the headlines.
In 1997, Simard and colleagues reported carbon moving from birch to fir seedlings, and the press called it the "wood wide web". The idea grew into "mother trees" feeding their young.
In 2023, Karst, Jones and Hoeksema reviewed the field and found three claims often repeated beyond the evidence:
- Networks are widespread in forests: few studies map them.
- Resources move through networks to seedlings: results are mixed.
- Trees favour their kin through the network: very little support.
Evidence: contested
The trade between each tree and its fungus is solid (see Mycorrhizal networks). The rest is an open question, not a settled fact.
Related: Carbon transfer, Reading list
