Fungi in the Homestead and Farm Ecology
This article discusses the functions of fungi in the ecology and some of the roles they have played and can play as allies in the homestead and farm. Some of this material appeared as the opening sections of “All About Mushrooms”, published in the August-September 2010 issue of Mother Earth News. Added to the site January 27, 2013.
The key to success in the homesteading, food-self-sufficiency enterprise is making alliances with plant and animal species. Fungi represent an entirely separate kingdom of life (neither plant nor animal) that can also help us create a more balanced, integrated, and productive backyard ecology. Let’s take a closer look at these fascinating beings—the role they play in the ecology and what they have to offer on the homestead and farm. (A related article, “Cultivating Mushrooms”, describes the cultivation of some edible and medicinal species.)
The thing that all fungi have in common, and which distinguishes them from the other biological kingdoms, is that fungi exude powerful enzymes to digest food externally, then absorb the resulting nutrients directly into their cells. Reproduction among fungi centers on spores—carriers of genetic information for the generation of new individuals, similar to seeds among plants, but far smaller—indeed, microscopic—and emitted by the billions. If conditions are right, they germinate into long thin strands called hyphae. Though fungi, unlike plants and animals, do not divide into “male” and “female” genders, each hypha contains half the genetic material needed to produce fertile offspring. When two compatible hyphae fuse, their genetic material combines into one complete set of DNA code; and from that point grows as a single mycelium, the fuzzy material we see, for example, in a rotting log or in the lower levels of leaf litter. The “mushrooms” we see in our walks through meadow and forest are special reproductive structures grown by the mycelium to mature and release spores, and begin the cycle anew.
Fungi are fed on by many players in their ecology, especially bacteria. Upon sprouting from spores, they are extremely vulnerable, and are often overwhelmed and consumed by bacteria before they can become established. If they survive this initial crisis, however, they begin synthesizing potent antimicrobial compounds that protect them from bacterial assault. They also develop the capability to defend their own mycelial “territory” from fierce competition by other fungal species.
There are four classes of mushrooms, based on their main strategies for nourishing themselves: parasitic, endophytic, mycorrhizal, and saprophytic. Though the parasites (which feed on the tissues of living plants) have been thought of as destructive to forests, they actually play positive roles as well—weeding out weakened trees, nourishing other classes of organisms, and renewing habitats following periods of stress. Endophytes form mostly beneficial partnerships with many types of plant, from grasses to trees, assisting them in absorbing nutrients and boosting growth, and helping protect them from parasites, disease, and predation from other organisms (insects, herbivores, other fungi) that feed on them. They offer a number of interesting applications in agriculture and forest management.
Mycorrhizae form beneficial partnerships with plants—including many crop plants—in their root zones, helping to feed plant roots, and protecting them from disease and other threats in the soil. Sometimes they form such relationships with several species at once, and can actually transport nutrients from one of them (for example birches) to others under stress (for example young fir trees with restricted access to sunlight in their early years) to help sustain them and thus keep in being a healthy ecology. Some sought-after wild edible species are mycorrhizal, such as boletes and chanterelles. They have resisted cultivation (since their growth depends on duplicating a whole interdependent community, not all of whose members are known), though some progress has been made in cultivating mycorrhizae such as morels and truffles.
Saprophytes are decomposers, feeding on dead organic tissues while breaking them down to simpler components, making them available to other members of the ecology, and speeding the formation of soil humus. Since this group contains the most “easy” species for beginners, and since they have the longest history of cultivation, the related article, “Cultivating Mushrooms” focuses on them.
Roles Fungi Can Play
Paul Stamets, in Mycelium Running, discusses five major roles fungi can play in the human-fungi alliance (though others are emerging as we learn more about them):
There are many wild mushrooms which are not only delicious but highly nutritious—up to thirty-five percent protein (dry weight), and rich in minerals and ergosterols (precursors to Vitamin D), some of the B vitamins, complex carbohydrates, and more. In the past two or three decades, tremendous strides have been made in the cultivation of some of these species.
Please do note that a few species are lethally and potently toxic, and that the worst mushroom poisonings can be a horrible way to die—no mushroom devotee should eat any mushroom whose identification and safety are not absolutely certain. That sounds scary, but in truth is nothing new as we choose the foods available from our edible landscapes—the solanums, for example (potatoes, tomatoes, eggplants, peppers), are just one group of common garden and orchard plants that offer edible tubers or fruits, while other plant parts are seriously toxic.
This caution applies as much to cultivated as to wild species. Shiitake and oyster mushrooms, for example, are easy to identify when they begin fruiting on the logs in which we have inoculated them. A species like Pholiota nameko, however, is a close enough look-alike to the deadly Galerina autumnalis to require as careful identification of mushrooms on cultivated logs as for those gathered in the wild.
As noted above, fungi are potent synthesizers of enzymes, enzyme inhibitors, and natural antibiotics, used in digesting food sources and defending against challengers. There is a great deal of interest in the pharmaceutical industry in many of these compounds, which hold great promise for treating infections, adult-onset type 2 diabetes, immune disorders, arthritis, and obesity; preventing cancer or inhibiting tumor growth; etc. Many such possibilities are emerging as we learn more, but some species—reishi and turkey tail, for example—have long histories of medicinal use, especially in Asian medical traditions. Extracts from homegrown specimens, in the form of teas and tinctures, can be used daily as an immune system tonic.
In a world in which all living things die, the tasks of disposal and renewal are paramount. The bacteria, for example, leap on easily broken down organic materials like dead annual plants and manures, using them as food energy, passing some of that energy on to other players in the soil food web, and eventually helping in the conversion of organic “wastes” to soil humus. We see this process at work in a compost heap.
Most decomposers, however, are stymied by the extremely strong chemical bonds that make up cellulose and lignin in dense, high-carbon tissues such as leaves, bark, and prunings of shrubs and trees (or even the tougher parts of annual plants such as corn and sunflower stalks). Far too often, we send such materials off to choke our landfills, despairing of processing them in the compost heap.
Enter the saprophytes, the preeminent decomposers, who specialize in harvesting food energy by breaking these bonds, speeding the breakdown of these materials to their component nutrients, adding to soil humus and enhancing soil fertility. Using them as allies, we can keep high-carbon organic debris on the farm or homestead as a resource for soil fertility.
It is a sad fact of modern life that too many landscapes are seriously polluted by the castoffs of our industrial production system. Many species of fungi have the capability of cleansing sites of heavy metal contamination, spilled oil, and other toxic wastes—even chemical and biological warfare agents. One application that might be of interest to homesteaders: Burlap bags full of wood chips can be inoculated with appropriate fungal species, and laid like so many sandbags across pollutant pathways, such as the runoff from a high-confinement animal operation. The runoff, heavy with nutrients from manure and urine that act in natural water systems more like toxins, is blocked by the “bunker spawn” levee, which absorbs it. The fungi feed on the nutrients, cleansing the flow and protecting the quality of down-slope streams.
Stamets points out that certain species (Psilocybe spp., Amanita muscaria, and others) have long had important shamanic usage in some indigenous cultures. It is possible that mushrooms with psychoactive properties could offer much in psychotherapy or treatment of addiction; though experimentation along these lines is at present severely restricted because ingestion of such mushrooms is illegal in this and many other countries.
It is an interesting historic fact that much of what we have learned about cultivating mushrooms in the past few decades came directly from the highly creative, rigorously scientific experiments of young “hippies” of the 1970s and later—who were fascinated by the “magic mushrooms” encountered by Gordon Wasson in his now-famous visit with the Mexican curandera Maria Sabina in 1955. There were then few cultivated fungal species—among the exceptions were the common supermarket “button mushroom” (Agaricus bisporus) and, mostly in Asia at that time, shiitake (Lentinula edodes)—and indeed the common assumption was that fungi were largely impervious to cultivation. Through persistence and rigorous application of the scientific method, young “basement scientists” proved them wrong, discovering how to create sterile, sealed environments in which spores of the hallucinogenic species could germinate and thrive. Having established effective alliances with the psychotropic fungi, many of these innovators expanded their work into the cultivation of a broader range of edible and medicinal species.
It is ironic in the extreme that our society revels in our increased access to culinary mushrooms, and salivates over the prospect for huge profits in the pharmaceutical industry—though we’ve been happy to clap into jail, for years at a time, young scientists whose experiments were achieving the critical breakthroughs. One wonders as well about the state of constitutional liberty in a society that imprisons its citizens for ingesting fungi that have been growing alongside Homo sapiens for millennia, and for whom a number of cultures the world over have had profound gratitude and respect.