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Climate change, overfishing can spoil an expensive parasite



  Market
High quality pieces of caterpillar fungus were sold in Beijing in 2017 for more than $ 140,000 per kilogram, more than three times as much as gold. Caterpillar fungus harvesting has become a major source of income for hundreds of thousands of collectors in the remote high mountains where it grows. (Photo credit: Kelly Hopping)

A parasitic fungus that grows wild in the Himalayas and sells more than its weight in gold could disappear as the current crop and climate trend continue, according to a new Stanford University study , 19659004] The fungus, Ophiocordyceps sinensis survives by capturing caterpillars in some of the highest regions of the Himalayas. The fungus infects and eats the inside of a caterpillar, which penetrates underground into the winter. What the parasite will do next may be too scary to mention about a supposedly healing bowl of aphrodisiac soup (Price: $ 688), made in Las Vegas in fifteen minutes.

"It kills them and then sprouts their heads like a unicorn," said lead author Kelly Hopping, an ecologist who conducted postdoctoral research at Stanford's Earth, Energy, and Environmental Sciences School (Stanford Earth).

Beginning in the 1990s, demand for the fungus as an aphrodisiac, anti-impotence drug and cure for the deadly SARS virus helped – without scientific evidence – to boost global trade. Since then, belief in a wide range of beneficial effects of the fungus has spurred a $ 11 billion market, as well as concerns that crop yields have become unsustainable.

However, official crop records are unreliable because of a lack of health Much of the caterpillar fungus trade goes through illegal channels. This new study, published in the reviewed Proceedings of the National Academy of Sciences presents the most comprehensive data to date on whether and why caterpillar fungus production may be declining, potentially causing a crash for communities, Mushroom

Endangered Species and Livelihoods

  Mushroom
From May to June, collectors dig out infected caterpillars with tailed fungus, usually before they start producing spores – a strategy that will affect population dynamics in the long term could. (Photo credit: Kelly Hopping)

Hopping and study co-author Eric Lambin, a Stanford professor of Earth system science, was interested in the mushroom as a way to understand what happens when a niche product supplies rich consumers with disproportionate influence on rural ones Livelihoods, Land Use Options, and Ecosystems in Producer Regions

Ecosystem degradation research tends to focus on the expansion of globally traded agricultural commodities such as oil palm, soybean, livestock, and wood – the largest drivers of deforestation. The wave effects of commodities that grow and trade on a smaller scale are less understood – but potentially profound, Lambin said. He refers to the rhino horn as an example.

"An emblematic mammal species is becoming extinct due to the demand for a product that is considered a virtue in some traditional cultures," said Lambin.

Caterpillar fungus may lack the charisma of a rhinoceros, but as one of the world's most expensive biological raw materials, it has become a major source of income for hundreds of thousands of collectors. And at a time when up to a third of Earth's parasite species could die out in a matter of decades – which could open new niches for other invasive parasites – conservation biologists are increasingly seeing the need to protect parasites and their hosts.

According to Lambin, who is also a Senior Fellow at the Stanford Woods Institute for the Environment, there is no question that an intense harvest in an increasingly vulnerable landscape is affecting people and the environment. While many local collectors are trying to minimize impact, he said, large influx of people in the Himalayan areas during the high-harvest harvest can degrade degrading ecosystems by disrupting soils, shrubs and trees for fuel and waste to their crops

& # 39; Himalayan gold & # 39;

Widely known in Tibet as yartsa gunbu or "summer grass, winterworm", caterpillar fungus has been used in traditional medicine in the Himalayan region and in China for centuries to treat diseases ranging from cancer and kidney disease towards inflammation and aging processes. In recent years it has been nicknamed "Himalayan Viagra" and "Himalayan Gold".

To address the issue of patchy trade data for the valuable fungus, the team turned to collectors' knowledge of production trends in China, Bhutan, Nepal, and India, as reported in dozens of case studies. The researchers then confirmed the published reports by interviewing 49 collectors on the Tibetan Plateau.

Using these data and 400 records of where the fungus was found in the four countries since the 1970s, the group built models of how much fungus would grow in a given area based on factors such as climate and altitude. The results show that the fungus is more productive in higher, colder areas around the edges of permafrost soils.

Warmer Winter

At present, the caterpillar fungus is plentiful in spring in magnificent production areas, which many people may gather enough in a month or two to sustain themselves for the rest of the year. However, production is already declining due to the intense harvest – and warming winters could exacerbate this trend.

In a region where average winter temperatures in some places have risen by as much as 4 degrees Celsius since 1979 – "a tremendous warming," said Lambin – the researchers found that every degree of winter warming makes it harder for thrive the mushroom. When the permafrost disappears from the lower elevations, the fungus can adapt by shifting to colder, ascending habitats, only when its caterpillars – and the vegetation and seasonal patterns they depend on – also shift upward.

In the long term, if income from caterpillar fungus can be maintained, the study suggests it could provide an important financial cushion for those whose livestock farming living on Hochalm prairie faced growing threats to climate change. "The caterpillar fungus collection has emerged as a way for people in these areas to make relatively easy money," Hopping said, "and in some cases, really increase their standard of living." However, reducing the environmental impact could exacerbate the tensions over access to the harvesting areas, Hopping said. Englisch: www.cosmetic-business.com/en/showar…p?art_id=844. "Communities in areas where they are still growing need to be alert to potential conflict and poaching as people try to harvest this increasingly rare and valuable species."

Lambin is also the Prostial Professor George and Setsuko Ishiyama. Hopping is now Assistant Professor at Boise State University College of Innovation and Design. Study co-author Stephen Chignell is now a Ph.D. student at the University of British Columbia.


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