2,000 kinds of mushrooms call Ohio home
- Herb Broda: Nature Notebook
- March 24, 2019
- 1766
Nature Notebook
For some, spring means gathering bouquets of daffodils; for others, it signals open season on mushrooms. But that colorful little toadstool you see on a forest walk has quite a story to tell. It’s just the tip of a mind-boggling botanical iceberg.
I’m talking about an internet of fungus under our feet: the wood wide web, the earth’s natural internet.
Underneath those mushrooms is a mass of branching, thread-like filaments called the mycorrhizal network. Sounds really fancy, but it’s just a combination of fungus (myco) and root (riza).
These strands can grow around as well as inside tree roots. The fungi provide water and nutrients to the roots and in turn receive sugars from the plants. Some scientists estimate hundreds of miles of threadlike filaments can be found under just one footstep.
In the mid-1800s the King of Prussia commissioned German biologist Albert Bernard Frank to develop practical methods for cultivating yummy truffles. Although he didn’t revolutionize truffle production, he coined the term mycorrhiza and forever changed how scientists view the interrelationships of fungi and plants.
Through this vast structure of filaments, fungi can connect the roots of trees and other plants. This internet of fungus is analogous to our electronic world wide web. Like our digital networks, plants can share resources, provide assistance, signal danger and even promote good parenting. Oh, and there is a dark side to this internet also, but more about that later.
Mother trees
Suzanne Simand is a Canadian biologist and forester. She is credited with coining the term wood wide web to describe the fascinating interactions that can occur beneath the forest floor. Her many years of research have shown that trees of different species can share nutrients through the fungal network.
Simand’s research focused on the concept of hub trees or “mother” trees. These are the most mature trees in an area and can be connected underground to hundreds of other trees through the fungal network. She found that these mother trees will send extra nutrients to young seedlings in need of a boost. It also appears that older trees reduce their root mass to provide some room for young saplings.
When a tree is under stress from insect infestation or disease, the tree sends out chemical signals to other healthy trees so they can increase their own resistance. Simand and other researchers also have found dying trees will send more of their nutrients to other trees in the area.
Just like the electronic internet, there is a dark side to the internet of fungus. There are hackers, like a species of orchids that tap into the mycorrhizal network and steal nutrients. Black Walnut trees also use the network to spread toxic chemicals to their neighbors to lessen competition.
Although this all sounds very human-like, Simand is not suggesting trees are making decisions like people. Some scientists even feel these are just chemical reactions that happen and are not directed to any specific tree or purpose. Although the debate continues, everyone agrees there is networking going on through the earth’s natural internet.
Find time to take a walk in the woods this spring. But as you look up, consider also the “conversations” that are taking place beneath your feet.
Humongous fungus
As you sauté mushrooms for dinner, reflect on this: They have a relative that is the largest single living organism on earth. It’s a type of honey mushroom that lives in Oregon called Armillaria ostoyae, or more affectionately, humongous fungus.
The mammoth Oregon fungus covers nearly 4 square miles: That’s equivalent to 1,665 football fields. It weighs at least 7,500 tons, although some claim it may be as heavy as 35,000 tons. It’s hard to guess age, but it’s at least 2,000 years old and probably much older. Of course what we can see is just a tiny part of the story.
This is a pathogenic fungus, not really a nice guy when it comes to trees. In fact it has been decimating the forests in which it grows in Oregon. It grows around the base of trees and effectively girdles the tree, cutting off the movement of nutrients.
We do have some varieties of honey mushrooms in Ohio but not the humongous fungus type found on the West Coast. Ohio has a lot of mushrooms, though: Over 2,000 kinds call Ohio home.
Email Herb Broda at 4nature.notebook@gmail.com.