Culture
The truly amazing world of fungi (Rebroadcast)
In this rebroadcast of 'The Truly Amazing World of Fungi,' we explore the crucial role fungi play in Earth's ecosystems, from aiding the first land plants to their modern applications i...
The truly amazing world of fungi (Rebroadcast)
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The land here is barren, harsh and hostile. There's no vegetation in sight. The only plants
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that exist live in the ocean, but that's all about to change. This is planet Earth around
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500 million years ago. A major shift is underway. At this point in history, plants are preparing
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to move from water and onto land. But it's not going to be easy. What people don't know is that
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the first land plants, they didn't even have proper root systems. Without roots, how would they
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absorb nutrients and feed themselves? Well, they're going to need help, from an organism with a
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special talent for getting at the good stuff locked away in the rocky surface. Fungi.
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Fungi have a sort of a magic power where they can digest their food outside of their bodies.
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So they actually exude enzymes and chemicals to break down rocks. And as the fungi digested
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rocks, they started feeding some of this digested nutrients to plants. Toby Kiers is a professor of
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evolutionary biology at the Free University in Amsterdam. Plants depended solely on Fungi to
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sort of act as a root system for millions of years. You know, roots, plant roots are kind of a
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new evolutionary innovation. The first land plants team up with Fungi and start trading with them
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in order to survive. A you scratch my back, I'll scratch yours kind of arrangement. And that was the
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beginning of this evolutionary, really evolutionary innovation. This one partnership that led to a 90%
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reduction in atmospheric CO2 as plants started colonizing land and using that CO2 to make sugars
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and fats that they would then feed to the fungi to get at those rock nutrients.
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This special partnership was crucial for the success of early land plants. They flourished and
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evolved, triggering a drastic transformation. The planet began to turn green. Ecosystems emerged.
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The composition of the atmosphere changed, becoming rich in oxygen, while carbon dioxide levels
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dropped by 90%. Creating an environment that would allow animals to evolve on land as well.
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Fungi lie at the base of life on earth. Actually, what what much we see today around ecosystem. So
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we actually owe to fungi, you know, from wolves to redwoods. It's the partnership between the
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ancestors of migrazo fungi and aquatic plants that help build our terrestrial ecosystems. Without
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Fungi, we wouldn't be here. All these millions of years later, that special partnership between
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fungi and plants endures. Today, most plants still depend on fungi in the soil for survival,
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to feed them nutrients and protect them from disease. And that's just one class of fungi.
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Fungi also give us food like mushrooms and life-saving medicines. They can digest pollutants
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and their ability to lock away carbon underground also offers a solution to climate change.
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So, as you can tell from that still very incomplete list, fungi are major players on this earth,
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and we ignore their potential both the good and bad at our peril. This is Living Planet,
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my name is Neil King, and on this week's show, we're going deep into the truly amazing world of
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Fungi.
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When you hear the word fungus, what comes to mind? Well, maybe you're thinking about those semi-circular
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growths on tree trunks in the forest, or some mold on a piece of fruit, or even a nasty skin
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infection like athlete's foot. These are all part of the fungus kingdom, yeasts, molds,
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and perhaps best well-known mushrooms. Mushrooms are the fruits of fungi that you see growing above
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ground, but most of the time, fungi take the form of mycelium, a root-like structure that looks
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a bit like tiny threads branching out, absorbing nutrients from the environment. They might seem
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like plants because they don't move around much and often grow in soil, but fungi actually have
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more in common with animals, because they also have to find food and use enzymes to break it down.
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Fungi are often invisible to the human eye, and out of sight, they're performing an essential role
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in nature, breaking down organic matter and orchestrating the trade and flow of nutrients in the
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environment. Wood wouldn't rot and release nutrients without fungi. There'd be no soil without
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fungi. They seem to weave their way into everything, and it's almost paradoxical because
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they're so vast and they underlie in so many processes that sometimes we don't even notice
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they're there. It's like not noticing our own breath. There are around 150,000 species of
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fungi that have been formally identified, but estimates suggest there could be more than 2.5
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million out there. That means more than 90% of all fungal species are still unknown to science,
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and that new discoveries are happening all the time.
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It's June 2020, and deep inside a cave, about an hour's drive from Kunming City and Southern
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China, a research team has come to search for fungi. There's some old wood on the ground,
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dead insects and bat droppings. The team from the Kunming Institute of Botany has collected
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some samples to test back at the lab. Peter Mortimer is a professor at the Kunming Institute of
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Botany, focusing on fungi and fungal ecology. He is originally from South Africa, and besides
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fungi, he's also passionate about caves. I could see there was a bit of black on the surface of the
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styrofoam, and so we thought we would see if that is a mold and what it's doing and turned out to be
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quite an interesting find. So we studied the fungi growing on that styrofoam and found
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was a new species to science. And that wasn't all. It turned out this new species of fungi also
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had the ability to digest the styrofoam, the plastic it was growing on.
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Coming out of a cave exploration trip, we found not only novel species, but really species with
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potential impact for broader industries. So that kind of stands out in my mind as
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an example of why we should study unexplored habitats.
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Peter has been living in Kunming Yunnan province for more than a decade. In that time,
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the teams he's worked with have discovered hundreds of new species, and that's perhaps not as
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surprising as you might think, because Yunnan has an incredibly rich biodiversity when it comes to
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fungi. We've described more than a thousand new species now. So it really is just mind blowing how
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much we are finding here. We're really scratching the surface of what we're finding and what is known.
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Arguably it is the most biodiversity place. It's an incredible region to work in. It
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you've got Alpine mountains above 5,000 meters elevation to the north and a few hundred kilometers
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to south. You're in tropical rainforests. So all these habitats and everywhere in between
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means there's opportunity and niches for speciation and the development of fungal diversity.
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If you look just at mushrooms, there's about 850 species of edible mushrooms in Yunnan,
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and globally there's only about 2,100. So nearly half of the world's edible mushrooms are just in
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this one province of China. So an incredible diversity.
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Fungi and mushrooms play an important role in China, as key ingredients in Chinese cuisine and
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traditional medicine, and they're big for the economy too. China is the world's biggest mushroom producer.
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It's difficult to describe to someone just how important fungi and mushrooms are to the Chinese.
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The Chinese are incredibly passionate about fungi and they eat a lot of mushrooms. They use all
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sorts of fungi and mushrooms as natural medicines. If you want to put it in perspective, the Chinese
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produce harvest and consume about 70% of the world's mushrooms. So it is a huge volume of mushrooms
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getting eaten. Yeah, it ranges from fungi like the caterpillar fungus, which is harvested usually
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about 4000 meters in elevation. So really in high altitude meadows, this can be incredibly value.
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I think we said it's up to $60,000 a kilo. But there's other mushrooms. I mean, Matsutaki can fetch
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$3,000 or $4,000 a kilo at the start of the season. And areas that produce Matsutaki get
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violently protected. I mean, there's bear traps and vicious dogs that I've put in the forest,
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like the locals really guard their natural resources, their mushrooms. And that's their livelihoods.
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It's their annual income, villages, towns will be solely dedicated to the trade of mushrooms. You
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can go to some towns in Yune. That's all they do. It's mushroom trade, mushroom restaurants,
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guest houses aimed at mushroom tourism. Streets are named after mushrooms. It's really,
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it's crazy. Mushroom fiva is very high. So interesting, interesting place to be.
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Edible mushrooms and truffle are a valuable source of food for us humans. But we also rely on
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fungi for many other edible products, like yeast, to bake bread, water ferment beer, wine, vodka
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and soy sauce. It's a fungus, penicillin, rocker 40, that creates the unique flavor and texture
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of blue cheeses, such as rock for and stilton. And can you guess what we get from the fungus penicillinum
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camemberti? Well, it's a bit of a giveaways in it. It's the rind on soft cheeses such as
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greek and camembert. Fungi also gave us the antibiotic penicillin, which revolutionized modern
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medicine. They've also been used to develop medication to lower cholesterol and immunosuppressant
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drugs used to enable organ transplants. Enzymes produced by fungi are used industrially. Fungi
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have also been employed as pesticides and in the production of biodiesel. Most people don't
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don't con-conceive the role that fungi play across different industries. You would see it for
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maybe for baking and brewing in your yeast or mushrooms that you eat. The range of sort of things
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in your daily life that mushrooms or fungi contribute to, I think, would blow people away.
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The one example I find amazing is there's an enzyme out of certain fungus that's used to make
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Lego the building blocks children play with. Like, Fungi touched on so many different aspects of
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our lives that we are unaware of. We'll be right back after this short message. There are two kinds
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of people in the world. People who think about climate change and people who are doing something
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about it. On the zero podcast, we talk to both kinds of people. People you've heard of, like Bill Gates.
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I'm looking at what the world has to do to get to zero. Not using climate as a moral crusade.
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And the creative minds you haven't heard of yet. It is serious stuff, but never doom and gloom.
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I am Akshadrati. Listen to zero every Thursday from Bloomberg Podcasts on Apple, Spotify,
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or anywhere else you get your podcasts.
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So it's clear that fungi are incredibly versatile and we rely on them in so many ways.
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Take myco-risal fungi. This is the fungi that forms partnerships with plant roots in the soil.
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We heard about them at the top of the show. Well, 90% of plants depend on this fungi to survive,
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from crops to garden shrubs to trees in rainforests. This network sometimes cleverly called the
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wood-wide web is also used by trees to share resources with each other. And they've been shown to
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use it to receive advanced warnings of threats. For example, if they need to boost defenses,
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because a neighboring tree is under attack from pests. And Toby says these fungi, building networks
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underground, can also be powerful allies in the fight against climate change. Because myco-risal
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fungi act as a kind of vacuum to draw carbon into soil systems, keeping it out of the atmosphere.
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The fungi are really important in climate change and this is where we say fungi are more than
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just organisms, right? They're creating this underground infrastructure that helps
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soils actually store this massive amount of carbon. Toby co-authored a recent study published
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in the journal Current Biology that found the world's plants transfer around 13 billion tons of
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carbon to soil fungi each year. That's more than a third of current annual CO2 emissions from fossil
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fuels. It's enough to cancel out the annual carbon emissions from China, the world's biggest
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emitter. This carbon, this drawdown, is actually a major contributor to the structure and health
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of soils. I mean, soils in general, we know they store about 75% of all terrestrial carbon. And
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fungi, they're like the gateway of that carbon to the soil and they play a major role in making that
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carbon drawdown happen. Just as trees are built of carbon fungi, these fungal,
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micro-isal fungal networks are built of carbon. The second thing they do is so cool is they make
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sort of specific compounds. And these are compounds that are tough organic things that they make
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this soil stronger. They make, they make aggregates which are sort of chunky bits of soil that act
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as a stable carbon reservoir. So it reduces erosion and maintains soil structure. It makes the
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soil sticky. Underground fungi also hold soils together preventing erosion. And they increase the
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volume of water soil can retain, which is important during drought or flooding and for reducing
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stress that the trees might face in times of climate change. But this underground fungi is at risk.
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Micro-isal fungal are threatened by agricultural expansion, by deforestation, by urbanization.
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And I mean, if you're putting concrete over underground ecosystems, you're going to really destroy
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the biodiversity that's there. It's worrying. I mean, the data, the data are there. Scientists have
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been sort of trying to sound the alarm on the threats to underground ecosystems for decades.
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More than 90% of the earth's top soil could be degraded by 2050 according to the United Nations.
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It says one soccer pitch of earth erodes every five seconds.
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Logging can decrease the abundance of micro-isal fungi by as much as 95%,
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and intensive farming practices and use of chemicals like fungicides can also disrupt fungal networks.
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This is what we're worried about is what is going to happen to above ground biodiversity and stability,
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these ecosystems, if we lose the foundation of the soil, if we lose these micro-isal networks.
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You know, we call micro-isal networks the coral reefs of the soil because they support so much
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biodiversity and life. And it's hard to know what's going to happen.
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Toby is also the executive director of an organization called Spun, which stands for the
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Society of the Protection of Underground Networks. The group is currently working to map
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fungal networks around the world and advocate for their protection.
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Sometimes it really feels like a race against time. I mean, it's about 99.9% of the earth's surface
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that still needs to be sampled. But some of this biodiversity is disappearing, and so the urgency
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is quite real. The good news is that there's hope. I mean, these organisms, they are resilient.
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We do these experiments in the lab, for example, where we actually use a laser.
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And we cut them very finely, and we can see that depending on the conditions, they can actually fuse
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back together if the disturbance isn't too great. So, you know, there are ways that these organisms,
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they're very resilient. They've been around for millions of hundreds of millions of years.
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The world of fungi is varied and complex, and while these organisms underpin life on earth,
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fungi can also cause as harm. Fungi are behind common maladies like athletes' foot and ringworm,
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but they can also cause life-threatening infections, such as pneumonia. And the number of fungal
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infections has been growing. Of the 150,000 known species of fungi, only a few hundred are
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pathogenic to humans. Their microscopic and are usually only dangerous for people with compromised
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immunity. David Denning, a professor of infectious diseases in global health at the University of
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Manchester in the UK, says around 3.8 million people die globally every year as a result of
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fungal infections. That's more than malaria. But many of these cases go undetected.
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So, one of the reasons why we think there are many more deaths than that have been before is because
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the diagnosis has just been missed completely. The second problem is that they usually, not always,
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but usually complicate other diseases. So, if you have leukemia or you've had a transplant,
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and then you get a fungal infection and you die, it's attributed to the leukemia or to the
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transplant, not to the fungus. Rapid diagnosis is really the core need across the world.
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And that's a combination of doctor considering the diagnosis and the tests being readily available
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and the results turned around within 24-48 hours.
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The World Health Organization has sounded the alarm about the issue. In 2022, for the first time,
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it released a list of fungi considered to pose the most danger to humans. Among those of most
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concern was aspergillus fumigatus, a mould found in soil and decaying leaves, capable of producing
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life-threatening infections in people with weakened immune systems. Another one on the WHO's list,
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a yeast pathogen called Candida auris, was first identified in 2008 and has since spread around
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the world. Such fungi can also be difficult to treat because they've become increasingly
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resistant to the antifungal drugs. That's mainly due to the use of fungicides to spray crops.
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And there's also the possibility that climate change is making the situation worse,
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allowing some pathogens to adapt to higher temperatures and spread to people. Here's David again.
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So there are many different influences of climate change on fungal disease. So there are a few
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fungi that probably Candida auris, which has taken across the world as a multi-resistant
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blood-borne infection, was driven by warmer climates in seawater. We're not absolutely
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sure about that, but it's completely, it was never seen before 2008 and now it's a global pathogen.
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So we think that's possibly one reason. Another issue is the extreme weather that we're getting,
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which is causing a lot of damage to housing and flooding and other things. So people are getting
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exposed to many more fungi in damp moldy houses as a result of climate direct, climate damage.
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And that's a problem not so much for these systemic infections, which kill you in a week or two,
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but more chronic indolent infections related to what is often told black mold. And then the other
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thing is the issues around travel and migrations. So as the world gets hotter, some places in the
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world are become uninhabitable or they run out of water. And so we're seeing already and we'll
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receive many, many more mass migrations of people and they will take fungal disease with them.
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A good example of that, although they're not migrating out of India at the moment, this is more
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people just traveling. There's a multi-resistant skin fungus called tricophyte, or a causing ringworm.
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And it's resistant to the typical topical treatments that you'd use the creams and things like that.
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And it's starting in India about 10 years ago and it's a new fungus and it's now been found in
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many, many countries around the world. Quite a lot of cases in the US, which were missed for many years,
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for example. Humans aren't the only ones affected by these harmful fungi. Thousands of fungus
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species can cause disease in plants. The fungal disease, rice blast, destroys up to 35% of the world's
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rice crop each year. Fungi has also decimated populations of bats and frogs. So the consequences
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for food security and biodiversity can be serious. So where does that leave us?
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As dangerous as they can be for some, fungi also present huge opportunities. We've learned that
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modern medicine relies on fungi. They keep trees healthy and can even help us sequester heat trapping
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CO2. Some fungi have the ability to break down pollutants, such as crude oil in the environment,
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for example, after an oil spill, a process known as micro-remediation.
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Fungi have also been shown to digest plastic, as we heard from Peter in Kunming earlier in the show.
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But he thinks there's still a lot of untapped potential.
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The mainstream adoption of maelium-based packaging, replacing styrofoam and plastic packaging
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with maelium materials. That is definitely the biggest point of impact we can make
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with current technology. A company like EcoVate, of which pioneered it. I care recently gave a
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commitment to transition and to include maelium-based packaging for their products. That's a step in the
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direction we need to be going. I think this is an easy one that's available to us now. We need to
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look at the economics of it, scaling off such industries to be competitive and viable against
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such well-established industries in plastics and styrofoam. But the technology is there and I think
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the shift will happen. Maelium-based materials can also be used to replace energy-intensive
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building materials in the construction sector, or unsustainable materials in the fashion industry.
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I mean there's huge potential to revolutionise textiles and fashion,
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the electronics industry even. So I think we will see a whole change in revolution in a number
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of industries. But we have the technology, the economics needs to follow.
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There's one thing I want to leave you with. Consider all that fungi can do from feeding plants,
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of a million of years, to making medicines, to providing an economically valuable food source,
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to digesting plastic waste, and then consider that less than 10% of fungi species have been discovered
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so far. That means there is likely an abundance of fungi still out there with unknown potential.
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And that's what we also stand to lose if we fail to protect this complex and incredibly versatile
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life form.
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Today's episode of Living Planet was produced by Natalie Muller and me Neil King.
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Our sound engineer was Misha Ilshpringer. You can find this and all our Living Planet
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episodes wherever you get your podcasts. You can also find us on YouTube at DW Podcasts.
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We're always happy to hear from you so if you have any feedback, questions or story suggestions,
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please do send us a voicemail with your name and home country or town to livingplanetat DW.com.
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That's it for this week. Thanks for listening.
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I'm
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Sanyar Patel, Editor in Chief at Quantum Magazine. Our mission at Quantum is to cover what we call
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