One part of the mycelium had access to a big patch of phosphorus. Another part had access to a small patch. She was interested in how this would affect the fungus’s trading decisions in different parts of the same network. Some recognizable patterns emerged. In parts of a mycelial network where phosphorus was scarce, the plant paid a higher “price,” supplying more carbon to the fungus for every unit of phosphorus it received. Where phosphorus was more readily available, the fungus received a less favorable “exchange rate.” The “price” of phosphorus seemed to be governed by the familiar dynamics of supply and demand.
Most surprising was the way that the fungus coordinated its trading behavior across the network. Kiers identified a strategy of “buy low, sell high.” The fungus actively transported phosphorus — using its dynamic microtubule “motors” — from areas of abundance, where it fetched a low price when exchanged with a plant root, to areas of scarcity, where it was in higher demand and fetched a higher price. By doing so, the fungus was able to transfer a greater proportion of its phosphorus to the plant at the more favorable exchange rate, thus receiving larger quantities of carbon in return.
We still do not understand how those behaviors are controlled. And that is all from the new and excellent Merlin Sheldrake book Entangled Life: How Fungi Make Our Worlds, Change Our Minds, & Shape Our Futures.