Researchers dig deep, go across the nation to bring plant species back

An ancient cypress species once on the brink of extinction is spearheading a major ecological turnaround in southwestern China, as artificial propagation efforts move the rare tree from precarious survival to widespread reforestation.

Scientists and conservation teams at the Chongqing Xuebaoshan National Nature Reserve in Kaizhou district, alongside the Mayun Forest Farm, have successfully brought the cliff cypress (Thuja sutchuenensis) back from the edge. Reintroduced into the wild in 2015, the initial batch of artificially cultivated seedlings has reached full reproductive maturity and is now producing viable seeds independently.

A research team led by Guo Quanshui, a researcher at the Chinese Academy of Forestry, is working on a multifaceted mission involving propagation, wild reintroduction, ex-situ conservation and adaptive cultivation of the cliff cypress.

Ex-situ conservation involves the maintenance and preservation of living specimens outside their natural habitats. This process can include whole plants, seeds, pollen, vegetative propagules or tissue and cell cultures. Meanwhile, adaptive cultivation involves introducing new species into new areas to test their survival with technical support and expertise.

According to Yang Liuyan, deputy director of the Kaizhou forest bureau, ex-situ conservation efforts focus on regions with more favorable conditions than Kaizhou, such as areas south of the Yangtze River, including Kunming and Pu'er in Yunnan province, as well as regions in Hubei province. In contrast, adaptive cultivation trials are conducted in less hospitable areas like the Inner Mongolia autonomous region and Changdao Island in Shandong province.

"The goal is to enable the species to adapt to a broader range of environments," Yang said. "Ultimately, we hope to see this rare tree become a potential staple in national greening projects."

Currently, these trials are progressively unfolding across China, with the cliff cypress being planted and growing in new territories. This includes trials in multiple national nature reserves such as the Gaoligong Mountains in Yunnan province, Daqing Mountain in the Inner Mongolia autonomous region, Helan Mountains in the Ningxia Hui autonomous region and Tianhua Mountain in Shaanxi province.

At a breeding base in Leyuan village, Wenquan township — one of the four local cliff cypress breeding bases in Kaizhou — Yang emphasized a broader vision: "Our aim with ex-situ conservation and adaptive cultivation is to transform this species from rare to common. This way, it can be widely used in ecological conservation to achieve true harmony between humans and nature."