Rich biodiversity

The Yangbi maple is an example of successful human intervention to pull a species back from the brink.

"China is one of the world's most biodiversity-rich nations, and Yunnan in particular is home to more than half the country's wildlife species," said Li Dezhu, head of the Germplasm Bank of Wild Species at the Kunming Institute of Botany.

However, due to their low populations and sparse distribution areas, some species are under threat from many influences, such as climate change, human activity and natural disasters, he said.

Moreover, population growth of some plants, such as Manglietiastrum sinicum－a type of magnolia known as huagaimu in Chinese and a member of the Magnoliaceae family, a genus unique to China－is restricted by its limited reproductive cycle.

In 2011, it was placed on the International Union for Conservation of Nature's Red List of Threatened Species because fewer than 50 trees had been discovered in the wild. It could only be saved from extinction by artificial breeding because it rarely reproduces in the wild.

In 1983, the Kunming Botanical Garden propagated saplings from seeds that had been transplanted for conservation. After three decades, a 13-meter-high tree blossomed in the garden for the first time, indicating that the team's off-site conservation program had been successful.

"Implementing conservation action for such listed species is an urgent task," Li said.

As the first province to initiate action to protect plant species with extremely small populations, Yunnan has invested 140 million yuan ($21.7 million) to safeguard flora in the past 15 years. By the end of 2019, the province had launched more than 120 projects and established 30 conservation areas for 61 plant species, according to the Yunnan Forestry and Grassland Bureau.

In the PSESP Garden, a special zone in the botanical garden, visitors can learn about some of the most threatened plants with small populations by getting close to them and by reading and watching detailed descriptions of how they have been saved.

In the garden, Sun showed off a special tree under national first-class protection－the Qiaojia five-needled pine, which is endemic to Yunnan's Qiaojia county.

When the species was discovered in 1990, only 34 trees were found in the wild.

The species is characterized by low levels of genetic diversity, vulnerability to many threats and a limited distribution range.

After years of conservation efforts, nearly 7,000 saplings or seedlings have been artificially propagated and cultivated from scratch.