Friday, September 16, 2022

Mount Everest is teeming with life, from fungi to butterflies

Jude Coleman
 
© Photograph By J Dong Lei, Nature Picture Library 
The Tibetan snowcock (pictured in Tibet) is one of the species recorded on Mount Everest.

In the spring of 2019, Tracie Seimon would lie awake listening to the deep rumble of cracking ice. The glacier she was sleeping on at the base of Mount Everest was shifting beneath her tent.

Seimon, a molecular biologist at the Wildlife Conservation Society in New York City, spent three weeks trekking around that glacier. She hoped to create a snapshot of biodiversity in one of the planet’s most extreme environments—a mountain more than five miles high that’s prone to subzero temperatures, limited oxygen, and intense storms.

But despite its inhospitable nature, the world’s tallest peak is teeming with life. Seimon and her team found 16 percent of Earth’s taxonomic orders—a classification including families, genera, and species—on just Mount Everest’s southern flank. They recently published their findings in the journal iScience.

“You feel very small as you're venturing up into the mountains,” says Seimon. “It’s incredible.”

She adds that most trekkers aren’t aware of the abundant life around them.

Mount Everest’s base camp sits atop the Khumbu Glacier, where Seimon’s team lived during part of the study in tents alongside summit-seeking hikers. The colorful cluster of tents sees around 40,000 people every year, which can be disruptive to the surrounding ecosystem, says co-author Anton Seimon, an atmospheric scientist at Appalachian State University and a National Geographic Explorer.

In addition to the foot traffic, climate change is also straining the mountain, which is why researchers wanted to create a baseline for its biodiversity. Understanding what life exists on Mount Everest now will help scientists track changes in the future.

It’s “been a fascinating experience and a privilege to be part of the effort,” says Anton, who is married to Seimon.

Finding life in meltwater

The team went to Mount Everest as part of the Perpetual Planet initiative, a research collaboration between the National Geographic Society and Rolex studying Earth’s forests, oceans, and mountains. In addition to studying biodiversity, other teams set up new weather stations and collected ice cores. Like most researchers and hikers on Everest, their work was supported by a team of sherpas who carried equipment, maintained camp, and guided the scientists across the mountain.

Seimon’s key to finding signs of life was collecting DNA from pools of thawed water. All living things routinely shed environmental DNA, or eDNA, into the surrounding air, water and soil. Scientists can match up a snippet of unknown eDNA with existing data to find out what organism it came from, in the same way that a library barcode tells librarians information about a book. (Learn how eDNA is revealing secrets of animals’ lives.)

The researchers focused on Everest’s highest ponds and streams, located between 14,700 and 18,000 feet in the high-alpine zone and beyond. In total, the team collected just over five gallons of water from 10 water bodies around the Khumbu region. From that, they identified 187 different orders, one sixth of all of Earth’s taxonomic orders.

A taxonomic order is a classification that helps scientists chart how individual organisms are distantly related to each other. For example, humans are classified as Homo (genus) and sapiens (species), but also fall under the family Hominidae and the order Primate, which also includes lemurs, monkeys, and apes.

In some cases, researchers could identify organisms more specifically down to the genus level; but because so little data exists about Mount Everest’s inhabitants, there was often not enough information to cross reference the DNA in such detail.

Seimon says that Mount Everest and other high mountain ecosystems are understudied.

“The global landmass that exists above 14,700 feet is less than three percent of the global land surface landmass,” she says. “It was very exciting to find as much biodiversity as we found up there.”

Looking deeper on Everest

Among the organisms swimming, flying, and scurrying on Mount Everest’s seemingly barren slopes were tardigrades and rotifers, two hardy microscopic critters that can survive even in the vacuum of space. Butterflies, mayflies, and other flying insects were also present, in addition to various fungi, bacteria, and plants.

“It's the top of the world and it’s so inaccessible,” says Kristine Bohmann, a biologist from University of Copenhagen who works with airborne eDNA and was not involved in the research. She says the work shows that studying biodiversity doesn’t always require a full team of taxonomists and can sometimes be done simpler and more efficiently, even in harsh environments. (Meet the animals that thrive in extreme mountain conditions.)

More research will help create a better record of diversity on Mount Everest and document specific organisms. Performing future studies in different seasons may yield more biodiversity, and show which genera and species live on the mountain in different climatic conditions.

Having created a baseline, one of Seimon’s next goals is to compare the data with future sampling, particularly to document the effects of climate change on Everest’s biodiversity. Their work can help inform future studies, paving the way for more research on the roof of the world.

No comments: