'China’s hidden labs': Tiankengs may be hiding ancient trees and unknown life

Produced by: Manoj Kumar

Hidden worlds

Deep in China’s karst terrain, tiankengs—massive sinkholes—hold entire forests untouched by human hands, where ancient species thrive in silence.

Vertical jungle

A tiankeng discovered in Guangxi plunges over 190 meters deep and shelters trees as tall as 40 meters, unseen by civilization for millennia.

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Nature’s vaults

Shielded by steep cliffs and dense canopies, these ecosystems have evolved in secret, free from modern disturbance or environmental degradation.

Living fossils

Plants linked to prehistoric times, including rare ferns and Chinese rain bells, have adapted to low-light and nutrient-rich cave conditions.

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Nutrient trick

Despite limited sunlight, plants here absorb unusually high levels of key minerals, allowing lush growth in this hidden world.

Humidity haven

The tiankengs’ closed structure traps moisture and cool air, forming a unique microclimate that boosts biodiversity and resilience.

Oxygen islands

Negative oxygen ions fill the air, supporting vibrant life and potentially enhancing plant survival in extreme underground conditions.

Geology meets life

Two-thirds of the world’s known tiankengs are in China, making it a global hotspot for subterranean biodiversity and geological wonder.

Earth’s secrets

Scientists believe these heavenly pits could still harbor unknown species—living proof of evolution’s patient hand in untouched pockets.