Updated: Apr 29, 2022
Merlin Sheldrake’s “Entangled Life” is a fascinating book about the role fungi play on the stage of life. He tells the story of the fungus kingdom, without which all of our eco- systems would collapse. According to Sheldrake, fungi are ubiquitous and promiscuous, forming relationships with each other and crossing barriers to interact with other kingdoms. The vast majority of plants, including those on the prairie, depend on fungi for the uptake of nutrients and water. But fungi go mostly unnoticed and unappreciated. They live in a subterranean world, only becoming noticeable when they project gaudy displays of mushrooms, the fruiting bodies of the network which form spores for dispersal. These displays delight us all, especially when they appear in fancy patterns like fairy rings. But they are usually ephemeral, appearing overnight and then quickly vanishing. The network, however, remains and continues to be vital to the health of our prairies
Fungi have been around for a long time — possibly as long as 2.4 billion years. Over this time, many relationships have developed between fungi and other organisms. One of the best known is the relationship between fungi and green algae in lichens. Sheldrake points out that there are a wide variety of combinations of different fungi and algae in this symbiotic relationship, forming many different lichens. Recently, it has been found that other microscopic partners such as cyanobacteria have joined the dance. This ancient partnership has thrived through millions of years, and different species have adapted to a wide range of sometimes hostile conditions.
One common species, the elegant sunburst lichen, was brought to the International Space Station and left exposed to the extremes of outer space for 18 months. When it was brought back to earth, it thrived as if nothing had happened! This widespread lichen grows on rocks and is common on rocky bluff prairie remnants such as the photo below taken on Zoerb Prairie.
Lichens can be used to estimate the minimum number of years a rock face has been exposed. For example, the elegant sunburst is known to grow about half a millimeter per year. The diameter of the one in the photo is about 40 mm, so the rock has been exposed at least 80 years — but probably a lot longer! Other lichens, such as the yellow map lichen, grow more slowly and can be used to date older rock faces. Lichens also bring gorgeous color to the prairie all year long. If you're interested, bring a 10x loupe to look at their incredible beauty under magnification.
Perhaps more important than the biology of fungi, says Sheldrake, is their ecology or the relationships they form with other parts of the ecosystem. He says it’s becoming increasingly clear that an individual organism out of the context of its community can be a very different entity than when it’s mixed in with its neighbors. In fact, the lines between individual organisms seem to blur as more is learned about the interactions that take place in the tangle of life. From the microscopic to macroscopic, life intertwines to form a complex whole. The boundaries between individuals can even vary by time of year and conditions. At times it is quid, at others quo. Who is benefitting by how much, and at what time? Many of these details are still unknown.
Sheldrake points out that fungal or mycorrhizal networks are vast and ever-present beneath the surface of ecosystems. They criss-cross with each other, forming connections with the roots of their companion plants. Through this network, resources are shuttled back and forth. The most common patterns involve the movement of nutrients and water from fungus to plant and sugars from plant to fungus. These networks also conduct electrical signals, opening up the intriguing possibility of a sort of network nervous system — a truly mind-boggling concept!
Most of the time, these interactions are mutually beneficial. However, some plants are “all take and no give”, according to Sheldrake. These mycoheterotrophs tap into the fungal network and extract all they need to thrive, including carbohydrates from other photosynthesizing plants. An example of a mycoheterotroph is the Indian-pipe, usually found in woods but occasionally on prairies. Orchids, like the Great Plains Lady's Tresses pictured below as taken on Zoerb, are partial mycoheterotrophs. Most are completely dependent upon fungi early in their lives. Later, as they become more proficient at photosynthesis, they contribute a portion of the carbohydrates they make back to the fungal partner.
Other prairie plants tap into the fungal network indirectly by invading the roots of plants that have mycorrhizal relationships with fungi. Examples of these hemiparasitic plants include bastard toadflax, Indian paintbrush, and wood-betony.
Of course, we’d all be in trouble if the fungi were just composing and not decomposing as well. In a fascinating part of the book, Sheldrake explains that until the end of the Carbon- iferous period (290-360 million years ago), plant matter from wood-producing plants accumulated on the forest floor. This un-rotted material eventually robbed the atmosphere of so much carbon dioxide that it plunged the earth into a period of global cooling. Only when the white rot fungus developed the enzymes needed to break down lignin did decay of wood begin to occur. Now, all ecosystems depend on this ability of fungi to break down dead plant material for recycling into new life.
Hats off to the fungi that form the foundation of our living world! And while we’re at it, let’s give a toast to yeast, a fungus that causes bread to rise and ferments sugars into tasty champagne.