Some of China’s giant sinkholes – home to many of the world’s oldest forests are now attracting an influx of tourists and operators, sparking fears that the sinkholes could be lost forever. That is according to Laura Bicker, a Chinese correspondent for the BBC, who said thrill seekers are now lowering themselves deep inside sinkholes within the Guangxi province in the country’s south.
Home to two-thirds of the world’s 300 or more sinkholes, China has become a hub for scientists. Fei Ge—or Brother Fei as he is known to locals—guides experts from the UK, France, and Germany around the ancient sinkholes.
“The experts were astonished,” Brother Fei told the BBC. “They found new plants and told us they’d been researching for decades and had never seen these species. They were very excited. We couldn’t believe that something we had taken for granted nearby was such a treasure.”
Why are Sinkholes so rare?
Sinkholes are rare. Why China – and Guangxi – has so many because of the abundance of limestone. When an underground river slowly dissolves the surrounding limestone rock, a cave expands out of the ground. Eventually, the ground collapses, leaving a yawning hole. Its depth and width must measure at least 100m to qualify as a sinkhole. Some, like the one found in Guangxi in 2022, are much bigger, stretching 300m into the Earth and 150m wide.
For scientists, the pits are a journey back in time to study animals and plants they thought were extinct. They have also found species they had never seen or known, including types of wild orchids, ghostly white cavefish, spiders, and snails. Protected by sheer cliffs, jagged mountains and limestone caves, plants and animals have thrived deep in the Earth.
In recent years, videos of the Guangxi sinkholes have gone viral on social media, attracting a huge influx of Chinese tourists who want to scale the sinkholes. What is fun and daring for young people is a source of much-needed revenue in a province that was only recently lifted out of poverty.
Guangxi’s unusual terrain, with little farmland and mountainous borders, makes trade difficult with the rest of China and neighbouring Vietnam. Still, people come for the views. Pristine rivers and the soaring karst peaks of Guilin and Yangshuo in the north draw more than a million Chinese tourists each year. Photographs of mist-covered Guangxi have even made it onto the 20-yuan note.
Yet few have heard of Ping’e village, the nearest settlement to the sinkholes. But that is changing with Brother Fei telling the BBC that a steady stream of visitors is changing fortunes for some in Ping’e. “It used to be very poor. We started developing tourism, which brought many benefits, like when the highways were built. We were really happy knowing we had something so valuable here.”
Could tourism revenue override the demands for research?
However, there are concerns that tourism revenue could override scientific research demands. About 50km from Ping’e, developers have built what they say is the highest viewing platform, which overlooks Dashiwei, the second-deepest sinkhole in the world. Tourists can peer 500m down into this “heavenly pit.”
“We should better protect such habitats,” says Dr Lina Shen, a leading sinkhole researcher in China. “Sinkholes are paradises for many rare and endangered plant species. We are continuing to make discoveries.”
By studying sinkholes, scientists hope to understand how the Earth has changed over tens of thousands of years and the impacts of climate change. At least one sinkhole has already been closed to tourists to protect unique orchid varieties.
“Overdevelopment could cause tremendous damage. We should maintain their original ecological state,” Dr Shen says, adding that the solution lies in striking a balance. Hot air balloons, drones for aerial photography, and appropriate pathways for observation from a distance could allow tourists to view sinkholes closely yet remotely while disturbing as few organisms as possible.”
Brother Fei agrees but insists there are “clear rules” to protect the sinkholes and what they hold. To him, they are a prized find that has changed his life. He is now one of Guangxi’s most qualified climbers and a renowned guide for tourists and scientists, making him “very happy”.
Giant Karst sinkholes found with an ancient forest deep inside
Last year, Wood Central revealed that Chinese scientists had discovered a giant karst sinkhole more than 620 feet (or 190 metres) deep, containing a well-preserved primitive forest and the potential for new species.
The karst sinkhole dubbed ‘The Eagle’ is 490 feet (or 150 metres) wide and is more than 5 million cubic metres in size. Wood Central understands that is is part of a series of sinkholes interconnected via a cave system and an underground river, making the largest cluster ever discovered south of the Tropic of Cancer, according to Zhang Yuanhai, a member of the team organized by the Institute of Karst Geology of the China Geological Survey.
After abseiling 100 metres to the bottom of the pit, the leader of the cave expedition team, Chen Lixin, said the ancient trees at the bottom were almost 40 metres high, with some plants growing at shoulder height.
“The tree vines were entangling us like spider webs, and you have no idea how deep your next step was going to be,” according to Lixin. “The plants were so brittle that you could pull them down with your hands, but they’d recover just as quickly. When we returned [up], the path was hidden again.”
