In pics: guardians of endangered trees in SW China's Chongqing

Thuja sutchuenensis seedlings are seen at the Thuja sutchuenensis research base of Xuebaoshan national nature reserve in Kaizhou District of southwest China's Chongqing, Aug. 7, 2024. Wild Thuja sutchuenensis is an endangered species of gymnosperm endemic to China and under national first-class protection. In 1998, the International Union for Conservation of Nature declared Thuja sutchuenensis extinct, but the species was rediscovered in Chengkou County in 1999. At present, the number of wild adult Thuja sutchuenensis plants in the world is less than 10,000, and they are only distributed in the areas of Daba Mountains including Kaizhou District and Chengkou County of Chongqing.

In order to protect this endangered species, Yang Quan from Chongqing Xuebaoshan national nature reserve led a team to carry out the investigation and study of wild Thuja sutchuenensis communities, hoping to expand its population.

Through years of efforts, the research team chose to take cuttings as a method to realize the large-scale propagation of wild Thuja sutchuenensis. Up to now, a total of 2.7 million plants have been artificially bred. Since March last year, the artificially bred plants have been transplanted to 18 experimental bases in 11 provinces and autonomous regions including Yunnan, Ningxia, Shaanxi, Gansu and Xizang for ex-situ conservation and adaptive cultivation.

"We hope to take Thuja sutchuenensis as a typical case and to expand our experience to the rescue and protection of more endangered plants," Yang Quan said. (Xinhua/Huang Wei)

Staff members of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve patrol the fields at the nature reserve in Kaizhou District of southwest China's Chongqing, Aug. 8, 2024. (Xinhua/Huang Wei)

A staff member of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve takes a cutting of Thuja sutchuenensis plant at the research base in Kaizhou District of southwest China's Chongqing, April 26, 2024. (Xinhua)

Staff members of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve build a sunshade for Thuja sutchuenensis seedlings at the research base in Kaizhou District of southwest China's Chongqing, Aug. 7, 2024. (Xinhua/Huang Wei)

An aerial drone photo taken on Aug. 8, 2024 shows a view of Xuebaoshan national nature reserve in Kaizhou District of southwest China's Chongqing. (Xinhua/Huang Wei)

A staff member of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve sprays pesticide over Thuja sutchuenensis seedlings at the research base in Kaizhou District of southwest China's Chongqing, Aug. 7, 2024. (Xinhua/Huang Wei)

Staff members of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve remove the weeds among Thuja sutchuenensis seedlings at the research base in Kaizhou District of southwest China's Chongqing, Aug. 7, 2024. (Xinhua/Huang Wei)

Workers transplant Thuja sutchuenensis seedlings at a forestry base in Mangkam County, Qamdo, southwest China's Xizang Autonomous Region, June 5, 2024. (Photo by Zheng Yu/Xinhua)

Seeds of Thuja sutchuenensis plants are seen at the Thuja sutchuenensis research base of Xuebaoshan national nature reserve in Kaizhou District of southwest China's Chongqing, Aug. 7, 2024. (Xinhua/Huang Wei)

A drone photo taken on Aug. 7, 2024 shows Thuja sutchuenensis plants at the Thuja sutchuenensis research base of Xuebaoshan national nature reserve in Kaizhou District of southwest China's Chongqing. (Xinhua/Huang Wei)

Staff members of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve transplant Thuja sutchuenensis seedlings at the research base in Kaizhou District of southwest China's Chongqing, April 26, 2024. (Xinhua)

An aerial drone photo taken on Aug. 7, 2024 shows a view of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve in Kaizhou District of southwest China's Chongqing. (Xinhua/Huang Wei)

A staff member of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve measures the length of the root of a Thuja sutchuenensis seedling at the research base in Kaizhou District of southwest China's Chongqing, Aug. 7, 2024. (Xinhua/Huang Wei)

Transplanted thuja sutchuenensis seedlings are seen at a forestry base in Mangkam County, Qamdo, southwest China's Xizang Autonomous Region, June 5, 2024. (Photo by Zheng Yu/Xinhua)

Staff members of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve patrol the fields at the nature reserve in Kaizhou District of southwest China's Chongqing, Aug. 8, 2024. (Xinhua/Huang Wei)

Staff members of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve discuss the breeding technique with Guo Quanshui (1st R), expert from Chinese Academy of Forestry, at the research base in Kaizhou District of southwest China's Chongqing, April 26, 2024. (Xinhua)

Staff members of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve take records of Thuja sutchuenensis seedlings after transplantation at a forestry base in Mangkam County, Qamdo, southwest China's Xizang Autonomous Region, June 5, 2024. (Photo by Zheng Yu/Xinhua)

Staff members of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve remove the weeds among Thuja sutchuenensis seedlings at the research base in Kaizhou District of southwest China's Chongqing, Aug. 7, 2024. (Xinhua/Huang Wei)

Automatic spraying device waters Thuja sutchuenensis seedlings at the Thuja sutchuenensis research base of Xuebaoshan national nature reserve in Kaizhou District of southwest China's Chongqing, Aug. 7, 2024. (Xinhua/Huang Wei)

An aerial drone photo taken on Aug. 7, 2024 shows a view of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve in Kaizhou District of southwest China's Chongqing. (Xinhua/Huang Wei)

Staff members of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve monitor the growth condition of Thuja sutchuenensis seedlings at the research base in Kaizhou District of southwest China's Chongqing, Aug. 7, 2024. (Xinhua/Huang Wei)

A staff member of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve checks the condition of Thuja sutchuenensis seeds at the research base in Kaizhou District of southwest China's Chongqing, Aug. 7, 2024. (Xinhua/Huang Wei)

A staff member of the Thuja sutchuenensis research base of Xuebaoshan national nature reserve checks the condition of Thuja sutchuenensis seeds at the research base in Kaizhou District of southwest China's Chongqing, Aug. 7, 2024. (Xinhua/Huang Wei)