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.
A rare yellow penguin has been photographed for what is believed to be the first time.
- World-Renowned Photographer Documents Most Remote ... ›
- This Penguin Colony Has Fallen by 77% on Antarctic Islands ... ›
EcoWatch Daily Newsletter
By Stuart Braun
We spend 90% of our time in the buildings where we live and work, shop and conduct business, in the structures that keep us warm in winter and cool in summer.
But immense energy is required to source and manufacture building materials, to power construction sites, to maintain and renew the built environment. In 2019, building operations and construction activities together accounted for 38% of global energy-related CO2 emissions, the highest level ever recorded.
- Could IKEA's New Tiny House Help Fight the Climate Crisis ... ›
- Los Angeles City-Owned Buildings to Go 100% Carbon Free ... ›
- New Jersey Will Be First State to Require Building Permits to ... ›
By Eric Tate and Christopher Emrich
Disasters stemming from hazards like floods, wildfires, and disease often garner attention because of their extreme conditions and heavy societal impacts. Although the nature of the damage may vary, major disasters are alike in that socially vulnerable populations often experience the worst repercussions. For example, we saw this following Hurricanes Katrina and Harvey, each of which generated widespread physical damage and outsized impacts to low-income and minority survivors.
Mapping Social Vulnerability<p>Figure 1a is a typical map of social vulnerability across the United States at the census tract level based on the Social Vulnerability Index (SoVI) algorithm of <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/1540-6237.8402002" target="_blank"><em>Cutter et al.</em></a> . Spatial representation of the index depicts high social vulnerability regionally in the Southwest, upper Great Plains, eastern Oklahoma, southern Texas, and southern Appalachia, among other places. With such a map, users can focus attention on select places and identify population characteristics associated with elevated vulnerabilities.</p>
Fig. 1. (a) Social vulnerability across the United States at the census tract scale is mapped here following the Social Vulnerability Index (SoVI). Red and pink hues indicate high social vulnerability. (b) This bivariate map depicts social vulnerability (blue hues) and annualized per capita hazard losses (pink hues) for U.S. counties from 2010 to 2019.<p>Many current indexes in the United States and abroad are direct or conceptual offshoots of SoVI, which has been widely replicated [e.g., <a href="https://link.springer.com/article/10.1007/s13753-016-0090-9" target="_blank"><em>de Loyola Hummell et al.</em></a>, 2016]. The U.S. Centers for Disease Control and Prevention (CDC) <a href="https://www.atsdr.cdc.gov/placeandhealth/svi/index.html" target="_blank">has also developed</a> a commonly used social vulnerability index intended to help local officials identify communities that may need support before, during, and after disasters.</p><p>The first modeling and mapping efforts, starting around the mid-2000s, largely focused on describing spatial distributions of social vulnerability at varying geographic scales. Over time, research in this area came to emphasize spatial comparisons between social vulnerability and physical hazards [<a href="https://doi.org/10.1007/s11069-009-9376-1" target="_blank"><em>Wood et al.</em></a>, 2010], modeling population dynamics following disasters [<a href="https://link.springer.com/article/10.1007%2Fs11111-008-0072-y" target="_blank" rel="noopener noreferrer"><em>Myers et al.</em></a>, 2008], and quantifying the robustness of social vulnerability measures [<a href="https://doi.org/10.1007/s11069-012-0152-2" target="_blank" rel="noopener noreferrer"><em>Tate</em></a>, 2012].</p><p>More recent work is beginning to dissolve barriers between social vulnerability and environmental justice scholarship [<a href="https://doi.org/10.2105/AJPH.2018.304846" target="_blank" rel="noopener noreferrer"><em>Chakraborty et al.</em></a>, 2019], which has traditionally focused on root causes of exposure to pollution hazards. Another prominent new research direction involves deeper interrogation of social vulnerability drivers in specific hazard contexts and disaster phases (e.g., before, during, after). Such work has revealed that interactions among drivers are important, but existing case studies are ill suited to guiding development of new indicators [<a href="https://doi.org/10.1016/j.ijdrr.2015.09.013" target="_blank" rel="noopener noreferrer"><em>Rufat et al.</em></a>, 2015].</p><p>Advances in geostatistical analyses have enabled researchers to characterize interactions more accurately among social vulnerability and hazard outcomes. Figure 1b depicts social vulnerability and annualized per capita hazard losses for U.S. counties from 2010 to 2019, facilitating visualization of the spatial coincidence of pre‑event susceptibilities and hazard impacts. Places ranked high in both dimensions may be priority locations for management interventions. Further, such analysis provides invaluable comparisons between places as well as information summarizing state and regional conditions.</p><p>In Figure 2, we take the analysis of interactions a step further, dividing counties into two categories: those experiencing annual per capita losses above or below the national average from 2010 to 2019. The differences among individual race, ethnicity, and poverty variables between the two county groups are small. But expressing race together with poverty (poverty attenuated by race) produces quite different results: Counties with high hazard losses have higher percentages of both impoverished Black populations and impoverished white populations than counties with low hazard losses. These county differences are most pronounced for impoverished Black populations.</p>
Fig. 2. Differences in population percentages between counties experiencing annual per capita losses above or below the national average from 2010 to 2019 for individual and compound social vulnerability indicators (race and poverty).<p>Our current work focuses on social vulnerability to floods using geostatistical modeling and mapping. The research directions are twofold. The first is to develop hazard-specific indicators of social vulnerability to aid in mitigation planning [<a href="https://doi.org/10.1007/s11069-020-04470-2" target="_blank" rel="noopener noreferrer"><em>Tate et al.</em></a>, 2021]. Because natural hazards differ in their innate characteristics (e.g., rate of onset, spatial extent), causal processes (e.g., urbanization, meteorology), and programmatic responses by government, manifestations of social vulnerability vary across hazards.</p><p>The second is to assess the degree to which socially vulnerable populations benefit from the leading disaster recovery programs [<a href="https://doi.org/10.1080/17477891.2019.1675578" target="_blank" rel="noopener noreferrer"><em>Emrich et al.</em></a>, 2020], such as the Federal Emergency Management Agency's (FEMA) <a href="https://www.fema.gov/individual-disaster-assistance" target="_blank" rel="noopener noreferrer">Individual Assistance</a> program and the U.S. Department of Housing and Urban Development's Community Development Block Grant (CDBG) <a href="https://www.hudexchange.info/programs/cdbg-dr/" target="_blank" rel="noopener noreferrer">Disaster Recovery</a> program. Both research directions posit social vulnerability indicators as potential measures of social equity.</p>
Social Vulnerability as a Measure of Equity<p>Given their focus on social marginalization and economic barriers, social vulnerability indicators are attracting growing scientific interest as measures of inequity resulting from disasters. Indeed, social vulnerability and inequity are related concepts. Social vulnerability research explores the differential susceptibilities and capacities of disaster-affected populations, whereas social equity analyses tend to focus on population disparities in the allocation of resources for hazard mitigation and disaster recovery. Interventions with an equity focus emphasize full and equal resource access for all people with unmet disaster needs.</p><p>Yet newer studies of inequity in disaster programs have documented troubling disparities in income, race, and home ownership among those who <a href="https://eos.org/articles/equity-concerns-raised-in-federal-flood-property-buyouts" target="_blank">participate in flood buyout programs</a>, are <a href="https://www.eenews.net/stories/1063477407" target="_blank" rel="noopener noreferrer">eligible for postdisaster loans</a>, receive short-term recovery assistance [<a href="https://doi.org/10.1016/j.ijdrr.2020.102010" target="_blank" rel="noopener noreferrer"><em>Drakes et al.</em></a>, 2021], and have <a href="https://www.texastribune.org/2020/08/25/texas-natural-disasters--mental-health/" target="_blank" rel="noopener noreferrer">access to mental health services</a>. For example, a recent analysis of federal flood buyouts found racial privilege to be infused at multiple program stages and geographic scales, resulting in resources that disproportionately benefit whiter and more urban counties and neighborhoods [<a href="https://doi.org/10.1177/2378023120905439" target="_blank" rel="noopener noreferrer"><em>Elliott et al.</em></a>, 2020].</p><p>Investments in disaster risk reduction are largely prioritized on the basis of hazard modeling, historical impacts, and economic risk. Social equity, meanwhile, has been far less integrated into the considerations of public agencies for hazard and disaster management. But this situation may be beginning to shift. Following the adage of "what gets measured gets managed," social equity metrics are increasingly being inserted into disaster management.</p><p>At the national level, FEMA has <a href="https://www.fema.gov/news-release/20200220/fema-releases-affordability-framework-national-flood-insurance-program" target="_blank">developed options</a> to increase the affordability of flood insurance [Federal Emergency Management Agency, 2018]. At the subnational scale, Puerto Rico has integrated social vulnerability into its CDBG Mitigation Action Plan, expanding its considerations of risk beyond only economic factors. At the local level, Harris County, Texas, has begun using social vulnerability indicators alongside traditional measures of flood risk to introduce equity into the prioritization of flood mitigation projects [<a href="https://www.hcfcd.org/Portals/62/Resilience/Bond-Program/Prioritization-Framework/final_prioritization-framework-report_20190827.pdf?ver=2019-09-19-092535-743" target="_blank" rel="noopener noreferrer"><em>Harris County Flood Control District</em></a>, 2019].</p><p>Unfortunately, many existing measures of disaster equity fall short. They may be unidimensional, using single indicators such as income in places where underlying vulnerability processes suggest that a multidimensional measure like racialized poverty (Figure 2) would be more valid. And criteria presumed to be objective and neutral for determining resource allocation, such as economic loss and cost-benefit ratios, prioritize asset value over social equity. For example, following the <a href="http://www.cedar-rapids.org/discover_cedar_rapids/flood_of_2008/2008_flood_facts.php" target="_blank" rel="noopener noreferrer">2008 flooding</a> in Cedar Rapids, Iowa, cost-benefit criteria supported new flood protections for the city's central business district on the east side of the Cedar River but not for vulnerable populations and workforce housing on the west side.</p><p>Furthermore, many equity measures are aspatial or ahistorical, even though the roots of marginalization may lie in systemic and spatially explicit processes that originated long ago like redlining and urban renewal. More research is thus needed to understand which measures are most suitable for which social equity analyses.</p>
Challenges for Disaster Equity Analysis<p>Across studies that quantify, map, and analyze social vulnerability to natural hazards, modelers have faced recurrent measurement challenges, many of which also apply in measuring disaster equity (Table 1). The first is clearly establishing the purpose of an equity analysis by defining characteristics such as the end user and intended use, the type of hazard, and the disaster stage (i.e., mitigation, response, or recovery). Analyses using generalized indicators like the CDC Social Vulnerability Index may be appropriate for identifying broad areas of concern, whereas more detailed analyses are ideal for high-stakes decisions about budget allocations and project prioritization.</p>
By Jessica Corbett
Sen. Bernie Sanders on Tuesday was the lone progressive to vote against Tom Vilsack reprising his role as secretary of agriculture, citing concerns that progressive advocacy groups have been raising since even before President Joe Biden officially nominated the former Obama administration appointee.