In a remote town in southwest China’s Yunnan province, a team of researchers scrambles down slippery rocks into an abandoned Buddhists’ cave with only torchlights leading the way. Tiny leeches and microsnails glisten on the damp, green walls.
This cave in the town of Menglun is part of a vast system of limestone caves called karsts, which spans across more than 300,000 square miles in Southeast Asia and China. The karsts are home to an untold number of unidentified animal and plant species.
Alice Hughes leads an ecology group at the Chinese Academy of Sciences that is dedicated to identifying those species and protecting them before they’re lost to human development.
In recent years, her team and others have discovered numerous new species, including geckos, pseudoscorpions, millipedes, and cave beetles.
“The majority of karsts have never had a biological inventory,” Hughes says. “So every single time that a specialist group surveys a karst, they will find new species, be they looking at orchids, beetles, or millipedes. And most of those are being lost, undiscovered.”
The biggest threat to southern China’s cave-dwelling species is habitat loss from human activity. A lot of the area is being mined for limestone used to make cement.
In 2017, the world used 4.1 billion tons of limestone, of which China alone accounted for 2.4 billion tons, according to a United States Geological Survey report.
For China, with a population of 1.4 billion, that equated to about 1.7 tons per person per year.
“Every single one of these limestone hills can have species found nowhere else in the world,” Hughes says. “Given that these systems have up to 12 endemic species in a single hill, there is a lot that needs to be done.”
Based in Xishuangbanna, an autonomous prefecture in Yunnan on the northern edge of the Southeast Asian tropics, the team lives and works in China’s biggest and richest botanical gardens. They are the ideal playground for any budding ecologist, spanning 2,720 acres and home to 13,000 species of plants and a limestone forest.
This diversity means the location has been touted as an ecotourism destination. But visit one of the caves, and you’ll find that it looks more like a Disneyland attraction than a protected site.
The rock formations are lit up in technicolor, cement paths have been laid for easy access, and the caverns are adorned with statues of everything from Buddha to Mickey Mouse.
“In many ecosystems, tourism is used as a way to protect the ecosystem,” Hughes says, explaining that it also stops people from poaching bats in these caves. “It’s a double-edged sword because it has positives, but it can also be very dangerous to biodiversity in those systems.”
The lights, for example, can induce plants to grow there unnaturally. Hughes estimates that using motion detectors for the lighting and safeguarding parts of the cave would maintain almost all of the species present.
(Watch: In search of the world’s oldest tea tree in Yunnan)
However, there is no management agency in China responsible for overseeing protection of the caves.
“In most cases, there are no biodiversity surveys before development,” says Tian Mingyi, one of Hughes’ collaborators. His team has discovered about 100 cave-adapted ground beetles and 70 millipedes in recent years.
Hughes estimates that more than 90 percent of cave invertebrates in China remain undiscovered.
“At the moment, we have no idea how many new species there are.”
“At the moment, we have no idea how many new species there are,” she says. “It would be probably thousands of them, all vulnerable to extinction because we don’t know where they are, and most of them are not protected.”
Another researcher, Judson Wynne, an assistant professor at Northern Arizona University, says his team identified at least 10 new animal species just from two days of sampling four caves in southwest China’s Guilin in 2016.
(Watch: How climate change is affecting a town famous for its mushrooms)
“This attests to the impressive biological diversity that the south China karst supports,” Wynne says. “The region already supports the highest diversity of highly evolved cave fish on the planet.”
But accessing the caves is difficult work, which is why few ecologists do it.
“These small animals also have a role in the ecosystem.”
“Lots of researchers like to study big mammals, like tigers, elephants and rhinos,” Tian says. “But these small animals also have a role in the ecosystem. If you disturb one part of the food chain, it will disturb all of it.”
Hughes’ team works tirelessly, exploring dark caves and forests late into the night and writing up their findings over the weekends. They’re now accustomed to the darkness, crawling through narrow tunnels from one cave chamber to another. Some have begun learning rock climbing to access even more difficult locations.
(Watch: The tree in Hong Kong that’s under threat by poachers)
The risks of this research are high. On one expedition, a bumpy rural road was blocked by a recent landslide—apparently common because of soil erosion—and the only access to the cave was across a river with strong currents.
On another, the cave entrance was blocked by giant rocks, which had tumbled because of recent tremors. The team says earthquakes are frequent, not a helpful thought to dwell on while spelunking.
Still, Hughes says the work is important because more information about these ecosystems can lead to policies that better protect them.
“The only way we can protect the biodiversity is to understand where to protect,” Hughes says. “And that’s something we’re only just scratching the surface of.”
Adapted from an article first published in the South China Morning Post.
