Here are some further findings demonstrating how a dying tree of one species can transfer nutrients to a tree of an entirely different species through complex Rhizopogon mycorrhizal networks acting as conduits between trees… Heres an excerpt from a Scientific American article by Jennifer Frazer discussing this fascinating interaction, along with a link to the complete article.
No tree is an island, and no place is this truer than the forest. Hidden beneath the soil of the forest understory is a labyrinth of fungal connections between tree roots that scientists call the mycorrhizal network. Others have called it thewood-wide web.
The connections are made by the filaments of fungi that grow in and around plant roots and produce many of the forest mushrooms we know and love. They bond trees so intimately that the more you learn about them, the more it is a struggle to view any tree as an individual. Forest trees and their root fungi are more or less a commune in which they share resources in a fashion so unabashedly socialist that I hesitate to describe it in detail lest conservatives reading this go out and immediately set light to the nearest copse.
This story stars two trees. They are the interior douglas-fir and the ponderosa pine — hearty and prolific trees that grow over large spans of the American west. The ponderosa pine is my favorite conifer and maybe also my favorite tree. Its forests are full of air and light; its bark smells like butterscotch or vanilla when warmed by the sun.
Unlike many mycorrhizal fungi, which produce colorful and beautiful gilled or pored mushrooms at the surface, Rhizopogon makes what is called a “false truffle” — an underground spore-making body. Rhizopogon does start to peep through the surface litter, however, as it nears ripeness, as you can see above.
Like all truffles they make their living by enticing mammals with an irresistible smell to dig them up and eat them. The mammals’ digestive systems, fidgety personalities (in the American west, squirrels are often the mammals in question), and the call of nature do the rest. Many, many distantly related fungi have evolved to do this separately; it seems to be an adaptation favored in dry climates where low-humidities make traditional moist breeze-based spore dispersal methods less effective.Rhizopogon seems to have evolved from above-ground pore-bearing mushrooms called boletes.
The spores are produced in the many contortions inside the “fruiting body”, as you can see below. Click through to the original to magnify and appreciate the intricacy of this biological lace.
Mycorrhizal fungi like Rhizopogon partner with plant roots because each gets something out of it. The fungus infiltrates the plants’ roots. But it does not attack — far from it. The plant makes and delivers food to the fungus; the fungus, in turn, dramatically increases the plant’s water and mineral absorptive powers via its vast network of filaments. They provide far more surface area for absorption than the meager supply of short root hairs the tree could grow alone. What has not been appreciated until relatively recently is both how complex mycorrhizal fungal networks can be and that they can also act as conduits between trees. Much of the work I’m about to describe to you has come out of the laboratory of Professor Suzanne Simard at the University of British Columbia.