At about 4,500 meters above sea level in the Qilian Mountain Range in northwest China's Gansu Province, moss thrives.

The plant is scattered on the slope, in big or small green clumps.

It produces neither flowers, nor seeds, and is common around the world.

But scientists believe that the plant is critical to the formation of life.

In a study by the University of Exeter of the United Kingdom, researchers found that as one of the earliest land plants that colonized the land from 470 million years ago onwards, the plant is responsible for the levels of oxygen that sustains our lives today.

Series Introduction:

Qilian Mountains – a world unto itself

The Qilian Mountains are part of a critical mountain range in northwest China, home to numerous animals and plants that the country considers to be treasures.

In this series, CGTN Nature's crew takes you on a journey into the mountains, valleys, and deserts... presenting you the true Qilian, a different landscape.

(Cover image from screenshot)

(If you want to contribute and have specific expertise, please contact us at nature@cgtn.com)