The Underground Market

With their slow, swaying leaves, plants seem to enjoy a peaceful existence. But all is not as it seems, because below ground there is a frenzy of activity. Plant roots find themselves among teeming insects, worms, micro-organisms and countless fungal ‘roots’ called mycorrhizae. It with these fungi that the plant roots enjoy an especially close relationship, where nutrients are exchanged, and sometimes the fungi even grow into the plant roots.

Toby Kiers studies this living arrangement, this ‘mutualism,’ between plants and fungi. It seems that both sides benefit from the interaction, but how does it arise, and what are the conditions? Kiers is a pioneer in the application of economic theory to the relationship between roots and fungi, and she uses fluorescent nanoparticles to make the exchange of nutrients in the ground visible and measurable. There appears to be a true market place under ground. Plant roots negotiate with fungi about what they have to offer, and the fungi grow into the root which makes the best proposal.

In the end it all comes down to cheating: no natural thing or creature helps another without some element of self-interest. In other words: those plants and fungi are trying to deceive each other, and this only results in a mutually beneficial cooperation if both sides can come up with a strategy to deal with that deception. They are no different to humans.