China’s Hidden Crater Forests Mysteriously Thrive in the Dark

A new study has revealed that plants thriving in China’s giant craters are showing accelerated growth rates attributed to high levels of nutrients.

The karst terrain in southwestern China is characterized by deep pits up to 100 meters deep called tianqing (a word derived from Mandarin and meaning “heavenly pits”). These pits are home to ancient forests as well as unique plants. However, scientists have long puzzled over how these plants thrive in such an isolated habitat.

Now, scientists have discovered the secret to their success: an abundance of nutrients. Craters often signal disaster, but some, like Sinkholes, preserve nature.

Sinkholes are natural depressions found mostly in karst terrain, which is characterized by soluble rocks such as limestone, dolomite, and gypsum. Some are at least 100 meters (328 feet) deep.

The pits are home to plants that thrive in moist, shaded environments, with some species exclusive to the area. According to a report by Live Science, the pits are home to laurel, nettle, and ferns. Additionally, Sinkholes host modern karst forest plants, such as Nepali hog plum and Chinese rain bell. Unlike those on the surface, plants in the pits have easy access to nitrogen, phosphate, potassium, calcium, and magnesium.

These essential nutrients, which are often scarce above ground, fuel rapid growth, allowing the plants to access the limited sunlight that filters through from the depths. The study suggests that "plants can adapt to adverse environments by adjusting their nutrient content. Because of the steep slopes and steep terrain of Sinkholes, it has been less disturbed by human activities," the study said.

The researchers compared 64 plant species from inside and outside 30 pits in Liyi County, China. The focus of the study was to analyze carbon and nutrient levels to determine differences in plant growth strategies.

"Our study compared the stoichiometry of carbon (C), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) in leaves of plants inside and outside the Tianqing group in Dashui, Guangxi," the paper said. It is likely that these plants have evolved this unique strategy to survive in these low-light conditions.

They reduced their carbon content, instead focusing on nutrient uptake. This allows them to thrive in a humid environment without the need for water-saving structures.

On the other hand, carbon is crucial for terrestrial plants, providing structural support and helping to retain water. For this reason, surface plants were found to have more carbon.

“The forest outside the pit is characterized by high light intensity, rapid water evaporation, poor soil, greater interference from human activities, and easy soil loss,” the researchers wrote in the paper. “Based on the group analysis, the 64 plants can be classified into calcium-loving and drought-resistant plants, balanced plants, and high-yielding plants.”

The results were published in the Chinese Journal of Plant Ecology.

Source: Interesting Engineering - Published 4-August-2024 https://ar.rt.com/y131