Quantcast
Food
Shutterstock

Stinkhorns, Truffles, Smuts: The Amazing Diversity—and Possible Decline—of Mushrooms and Other Fungi

By Alexander Weir

"Whatever dressing one gives to mushrooms ... they are not really good but to be sent back to the dungheap where they are born."

French philosopher Denis Diderot thus dismissed mushrooms in 1751 in his " Encyclopedie." Today his words would be dismissed in France, where cooks tuck mushrooms into crepes, puff pastry and boeuf Bourguignon (beef Burgundy), to name just a few dishes.


The French aren't alone. Mushrooms and their biological relatives feature in global cuisines from Asia to sub-Saharan Africa. Here in North America, they are part of many holiday meals, from humble stuffed mushroom caps to a single costly truffle shaved over pasta. Late fall is wild-mushroom foraging season in much of the U.S., so it's a good time to learn about these fascinating organisms—and to know that some popular species are declining.

Fungi, Not Vegetables

Human experience with mushrooms dates back thousands of years, including references from China, Africa, Greece and Rome. One of the first is attributed to Euripides (A.D. 450-456), who commented on the death of a mother and her family from mushroom poisoning. Indeed, a few species are poisonous—notably, Amanita phalloides, the so-called death cap mushroom, which sickened 14 people in California in 2016. Three required liver transplants.

All the more reason to learn some mycology—the science of fungi. This mega-diverse group of organisms is biologically distinct from its better-known counterparts, plants ( Plantae) and animals (Animalia). Along with mushrooms, it includes such curiosities as conks, puffballs, earthstars, stinkhorns, birds-nests, truffles, morels, molds, rusts and smuts.

Unlike plants, fungi do not have chlorophyll, the pigment in plant leaves that converts light energy to chemical energy through photosynthesis. Instead, fungi are decomposers: They release enzymes that break down tissues from living and dead plants and animals to nourish them as they grow.

Most fungi grow in or on a natural substrate, such as dead logs or manure (Diderot was not wrong to say that they came from a dung-heap). Commercial mushroom growers use materials such as straw or coffee grounds. Mushroom spores put out filaments ( hyphae) that form a network (mycelium). This is the organism's feeding stage, and in some species can grow to an enormous extent, largely hidden in the soil.

Oyster mushroom mycelium growing in a petri dish on coffee grounds. Tobi Kellner

Almost miraculously, in response to a range of environmental cues such as moisture and temperature, this network produces "fruiting bodies" or reproductive structures, that typically erupt out of the substrate. These structures are what we think of as mushrooms. They come in many sizes, shapes and colors, and can either persist or appear and then disappear in a matter of hours or days.

The mysterious origin of these seemingly magical apparitions has fascinated humans for millennia. Certain species erupt naturally in circular formations, which are widely known as "fairy rings" and linked in European folklore with fairies and other magical creatures. Many accounts claim that psilocybin mushrooms, which contain hallucinogenic compounds, have been used for mind-altering purposes for millennia. Today they are being studied as a possible treatment for depression.

Abundant But Also at Risk

Even after more than 200 years of exploration, scientists estimate that only about 5 percent of a likely 1.5 million species of fungi have been described and named. Of those, roughly 10 described species have been "domesticated" and form the basis of the global cultivated mushroom industry, which has an annual value estimated at more than US$35 billion and rising. A 2004 United Nations Food and Agriculture Organization report documented use of more than 1,100 species in over 80 countries.

Meilinger Lab pdf. Bradley Meilinger

Detailed studies have helped to dispel the commonly held view that mushrooms are a low-calorie food with little nutritional benefit. We now know that they are typically low in fat, sodium and carbohydrates, but high in vitamin D, potassium and antioxidants. In short, mushrooms are increasingly recognized as nutritional powerhouses.

Historically, mushrooms were eaten mostly at subsistence levels in rural communities in developing countries. Recently, however, an export trade has developed for wild varieties, moving mainly from poor to rich countries. This growing demand reflects recognition of wild edible mushrooms' nutritional value, but has also been linked to a decline in the numbers and diversity of mushroom fruiting bodies in traditional centers of high consumption, such as Europe and Japan.

This trend is a serious concern for scientists, who are continuously learning more about the important ecological roles that fungi play. Some form relationships with plant roots that sustain the growth of native forests and commercial tree plantations. As decomposers, fungi also recycle nutrients from dead matter in many different types of habitats.

There are vast gaps in our knowledge about fungal biodiversity and how these organisms are affected by trade, land management practices, air pollution, habitat loss and global climate change. One recent study identified three unknown species of porcini in a packet of dried Chinese mushrooms purchased in a London grocery store.

Huitlacoche, a fungus that grows naturally on corn, is harvested as a delicacy in Mexico. Russ Bowling / Flickr

Many countries are developing or have published Red Data Lists of threatened fungi. The International Union for the Conservation of Nature is accepting information for a Global Fungal Red List Initiative that aims to assess and classify at least 300 species of threatened fungi.

Mycologists like me are also a dwindling resource. The number of positions at universities, research institutes and botanic gardens has declined in recent years. Inventorying, describing and understanding the impacts of human-induced and natural disturbances on fungal communities is a huge and challenging task, and an essential step toward determining whether harvesting wild fungi at the current level is sustainable. But this work is starting to gain momentum. Finally, humans are starting to see fungi not just as commodities or as biological organisms, but also as important contributors to ecosystem function that are worthy of conservation.

Reposted with permission from our media associate The Conversation.

Show Comments ()
Sponsored
Abdallah Issa / Flickr

Post-Fire Landslide Problems Likely to Worsen: What Can Be Done?

By Lee MacDonald

Several weeks after a series of wildfires blackened nearly 500 square miles in Southern California, a large winter storm rolled in from the Pacific. In most places the rainfall was welcomed and did not cause any major flooding from burned or unburned hillslopes.

But in the town of Montecito, a coastal community in Santa Barbara County that lies at the foot of the mountains blackened by the Thomas Fire, a devastating set of sediment-laden flows killed at least 20 people and damaged or destroyed more than 500 homes. In the popular press these flows were termed "mudslides," but with some rocks as large as cars these are more accurately described as hyperconcentrated flows or debris flows, depending on the amount of sediment mixed with the water.

Keep reading... Show less
The most notable observation from the count was DeMartino's sighting of the golden crowned kinglet, but in general volunteers found the same species they normally do. (Photo above is of a golden crowned kinglet, but not the one DeMartino spotted.) Melissa McMasters

Birders Get a First Look at How 2017 California Wildfires Affected Wildlife

By Matt Blois

A neighbor knocked on Rick Burgess's door at about 9:30 p.m. to tell him a fire was coming towards his home in Ventura, California. When he looked outside he saw a column of smoke, and the hills were already starting to turn orange. He loaded up his truck with a collection of native plants he was using to write a countywide plant guide, and barely had enough time to get out.

Keep reading... Show less
A learning garden from Kimbal Musk's nonprofit called Big Green. The Kitchen Community

Elon Musk's Brother Wants to Bring #RealFood to 100,000 Schools Across America

Kimbal Musk's nonprofit organization, The Kitchen Community, is expanding into a new, national nonprofit called Big Green, to build hundreds of outdoor Learning Garden classrooms across America.

Learning Gardens teach children an understanding of food, healthy eating and garden skills through experiential learning and garden-based education that tie into existing school curriculum, such as math, science and literacy.

Keep reading... Show less
Drilling fluids spilled into Ohio wetlands during construction of the Rover Pipeline in April. Sierra Club

Rover Pipeline Spills Another 150,000 Gallons of Drilling Fluid Into Ohio Wetlands

Energy Transfer Partners' troubled $4.2 billion Rover pipeline has spilled nearly 150,000 gallons of drilling fluid into wetlands near the Tuscarawas River in Stark County, Ohio—the same site where it released 2 million gallons in April.

The 713-mile pipeline, which will carry fracked gas across Pennsylvania, West Virginia, Ohio and Michigan and Canada, is currently under construction by the same Dallas-based company that built the controversial Dakota Access pipeline.

Keep reading... Show less
Sponsored

Large Dams Fail on Climate Change and Indigenous Rights

Brazil has flooded large swaths of the Amazon for hydro dams, despite opposition from Indigenous Peoples, environmentalists and others. The country gets 70 percent of its electricity from hydropower. Brazil's government had plans to expand development, opening half the Amazon basin to hydro. But a surprising announcement could halt that.

Keep reading... Show less
Jim Henderson / Wikimedia Commons

World's Largest Money Manager: Companies Must Respond to Social and Climate Challenges

The world's largest publicly traded companies must take a more active role in solving social issues or face blowback from investors, the CEO of BlackRock said Tuesday.

"To prosper over time, every company must not only deliver financial performance, but also show how it makes a positive contribution to society," Laurence Fink wrote in his annual letter to CEOs of companies in which BlackRock invests. BlackRock is the world's largest money manager, with more than $6 trillion in assets.

Keep reading... Show less
Sponsored
16:9clue / Flickr

Lawsuit Filed Against Walmart for Claiming 'Cage-Free' Eggs

By Dan Nosowitz

A lawsuit has been filed in a California district court against two of the biggest companies in the country: Walmart and Cal-Maine Foods. The lawsuit claims that Walmart and Cal-Maine—the latter is one of the biggest egg producers in the U.S.—lied to customers about the treatment of hens whose eggs were sold at Walmart. The alleged lie? The packaging claimed "outdoor access," yet the birds are not permitted to go outside.

Keep reading... Show less
Ryan Zinke. Gage Skidmore / Flickr

Majority of National Parks Panel Quits in Protest of Ryan Zinke

Nearly all members of the National Park Service advisory panel abruptly quit on Monday in protest of the Trump administration's policies, which they say have neglected science, climate change and environmental protections.

"From all of the events of this past year I have a profound concern that the mission of stewardship, protection, and advancement of our National Parks has been set aside," the head of the panel, Tony Knowles, wrote in a letter of resignation addressed to Interior Secretary Ryan Zinke, who oversees management of the country's national parks and monuments.

Keep reading... Show less
Sponsored

mail-copy

The best of EcoWatch, right in your inbox. Sign up for our email newsletter!