I sure hope 2021 turns out better than 2020 and I am sure you do too!! That was one strange year……. We have talked briefly about the symbiotic relationship between trees and fungi. This month I want to spend some more time on these fabulous fungi.
As you read these words, fungi are changing the way life happens as they have done for more than a billion years. They are eating rock, making soil, digesting pollutants, nourishing and killing plants, surviving in space, inducing visions, producing food, making medicines, manipulating animal behavior, and influencing the composition of Earth’s atmosphere.
Animals, plants, and fungi make up the 3 broad categories of life. The best estimate is that there are maybe 10 times as many species of fungi as there are of plants. But I for one was almost totally ignorant about these important creatures.
Mushrooms are only the fruiting bodies of fungi: for the most part, they live their lives as branching, fusing networks of tubular cells know as mycelium. Mycelial networks have no fixed shape. By ceaselessly remodeling themselves they can navigate labyrinths, solve complex routing problems, and expertly explore their surroundings.
The Social Life of Forests
As a graduate student in Forestry, Suzanne Simard understood that loggers were replacing diverse forests with homogenous plantations, evenly spaced in upturned soil stripped of most underbrush. The thinking was that without any competition the newly planted trees would thrive. Guess what actually happened?? They found out that up to 10% of the newly planted douglas fir were likely to get sick and die whenever nearby aspen, paper birch, and cottonwood were removed!!! As we talked about, underground, trees and fungiform partnerships known as mycorrhizas: threadlike fungi envelop and fuse with tree roots, helping them to extract water and nutrients like phosphorus and nitrogen in exchange for some of the carbon-rich sugars that trees make through photosynthesis. The other interesting thing here was that it was when they removed trees not of the same species but different ones. As if the trees of different species were cooperating with each other!!! Now I don’t want to get into the thickets of biological theory but remember ever since Darwin the idea has been that competition, not cooperation was what ruled interactions. So this was a big new idea.
Ms. Simard went on to study the webs of roots and fungi in the Arctic, temperate, and coastal forest of North America for nearly 30 years. What do you think she found? It turns out that these fungal threads link nearly every tree in a forest—even trees of different species. Carbon, water, alarm signals, and hormones can pass from tree to tree through these subterranean circuits. And even more interesting—the resources tended to flow from the oldest and biggest to the smallest and youngest. Seedlings severed from the forest’s underground network were much more likely to die. It turns out that old-growth forests are a vast ancient and intricate society. The trees, understory plants, fungi, and microbes are all connected. These mycorrhizal networks also perfuse prairies, grasslands, and Arctic tundra—essentially everywhere there is life on land. Depending on the species involved, Mycorrhizas supplied trees and other plants with up to 40% of the nitrogen they received from the environment and up to 50% of the water they needed to survive. Many of the most dramatic events on Earth have been the result of fungal activity. Plants only made it out of the water around 500 million years ago because of their collaboration with fungi which served as their root systems for 10’s of millions of years until they could evolve their own. Today more than 90% of plants depend on symbiotic fungi. Fungal networks, mycelium, are ecological connective tissue.
What Else Do Fungi Do?
Fungi are metabolic wizards and their chemical accomplishments have long shaped human life. Bread, cheese, soy sauce, penicillin, powerful anti-viral and anti-cancer compounds, cholesterol-lowering statins, and alcohol (fermented by yeast) are all results of fungal activity. I think you can agree—FUNGI ARE FABULOUS!!
Some Other Neat Things
The Nature Conservancy along with insurance company Swiss Re has figured out a way to have an insurance policy for a coral reef. A coral reef in Mexico is now insured against hurricanes. Coral reefs are only 1% of the planet but 25% of ocean species depend on coral reefs for food and shelter. These coastal ecosystems also protect coasts and support about half the world’s fisheries. And with no reef, there are no beaches so the Mexican state of Quintana Roo, home to Cancun and Tulum, bought reef insurance from Swiss Re since with no beaches there are no tourists. So 103 miles of coastline were insured with the policy paying off for category 3 storms. Unfortunately, it didn’t take long for the policy to pay off and the money was used to cement broken bits of coral back into place. The broken pieces can be saved if they are fastened back onto the reef.